Plants

18 pages, 1569 KiB

Open AccessReview

The Role of Iron in Phytopathogenic Microbe–Plant Interactions: Insights into Virulence and Host Immune Response

by Sheo Shankar Pandey

Plants 2023, 12(17), 3173; https://doi.org/10.3390/plants12173173 - 4 Sep 2023

Cited by 4 | Viewed by 2705

Iron is an essential element required for the growth and survival of nearly all forms of life. It serves as a catalytic component in multiple enzymatic reactions, such as photosynthesis, respiration, and DNA replication. However, the excessive accumulation of iron can result in [...] Read more.

Iron is an essential element required for the growth and survival of nearly all forms of life. It serves as a catalytic component in multiple enzymatic reactions, such as photosynthesis, respiration, and DNA replication. However, the excessive accumulation of iron can result in cellular toxicity due to the production of reactive oxygen species (ROS) through the Fenton reaction. Therefore, to maintain iron homeostasis, organisms have developed a complex regulatory network at the molecular level. Besides catalyzing cellular redox reactions, iron also regulates virulence-associated functions in several microbial pathogens. Hosts and pathogens have evolved sophisticated strategies to compete against each other over iron resources. Although the role of iron in microbial pathogenesis in animals has been extensively studied, mechanistic insights into phytopathogenic microbe–plant associations remain poorly understood. Recent intensive research has provided intriguing insights into the role of iron in several plant–pathogen interactions. This review aims to describe the recent advances in understanding the role of iron in the lifestyle and virulence of phytopathogenic microbes, focusing on bacteria and host immune responses. Full article

(This article belongs to the Special Issue Plant-Microbes Interactions in the Context of Abiotic Stress)

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Chemical structure of two of the most common iron–sulfur clusters: the 2Fe-2S (A) and the 4Fe-4S (B) clusters. These iron–sulfur clusters have been present in life since the ancient stages of evolution. Iron is abundantly present in metalloproteins as part of these iron–sulfur clusters, which play a crucial role in cellular redox reactions. Full article ">Figure 2
Bacterial iron homeostasis. The ferric and ferrous iron uptake pathways are independent in nature but markedly interdependent in regulation. Under high intracellular iron, the Holo Fur (Fur–Fe2+ complex) binds to the regulatory sites of iron uptake genes and turns off their expression. When intracellular iron levels are low, the Holo Fur releases the Fe2+ iron, and it turns into Apo Fur (Fur alone). The Apo Fur loses the ability to bind to regulatory sites, which makes the regulatory sites free from Fur and enables the expression of iron uptake genes. Bacteria synthesize ferric iron-chelating compounds, siderophores, and release them into the extracellular milieu to sequester ferric iron. The TonB-dependent outer membrane receptors recognize the Fe3+–siderophore complex, causing a conformational change in the plug domain of the receptor’s channel to internalize it. ExbB and ExbD energize TonB using an electrochemical charge gradient along the cytoplasmic membrane to release the Fe3+–siderophore complex into the periplasmic space. Further, periplasmic-binding proteins deliver the complex to the cognate ABC transporter to transport it into the cytoplasm. The ferrous iron is transported to the periplasm by Fe2+-specific porins. The glucan–Fe2+ complex can also bring ferrous iron to the periplasmic space. Further, the FeoB complex (FeoABC) transporter transports the ferrous iron to the cytoplasm. The outer membrane and cytoplasmic ferric reductases reduce ferric iron to ferrous iron at their respective places. Abbreviations: R = receptor; G = glucan; PBP = periplasmic-binding protein; EM = extracellular moiety; OM = outer membrane; P = periplasm; CM = cytoplasmic membrane; C = cytoplasm. Full article ">Figure 3
Iron in plant–phytopathogenic bacterial interactions. The host and phytopathogenic bacteria compete for iron resources during the in planta infection process and colonization. Plants limit the availability of iron for bacterial pathogens by transporting iron into the vacuole and sequestering it into ferritins. This results in low-iron conditions for bacteria, which trigger the induced expression of iron uptake genes and siderophore biosynthesis to obtain iron from the iron-depleted host environment. Low-iron conditions also induce bacterial motility and chemotaxis, as well as the expression of virulence genes, T3SS, and effectors. However, the response to low iron varies among bacterial pathogens. PAMP-induced PTI and effector-triggered ETI can cause the HR, which restricts bacterial growth. The siderophore pseudobactin has also been reported as a potential PAMP in Arabidopsis. Excess iron generates ROS via Fenton’s reaction, which triggers programmed cell death at low levels and necrosis at a threshold level. Full article ">

17 pages, 2173 KiB

Open AccessArticle

Fungal–Algal Association Drives Lichens’ Mutualistic Symbiosis: A Case Study with Trebouxia-Related Lichens

by Ya-Bo Zuo, Da-Yong Han, Yan-Yan Wang, Qiu-Xia Yang, Qiang Ren, Xin-Zhan Liu and Xin-Li Wei

Plants 2023, 12(17), 3172; https://doi.org/10.3390/plants12173172 - 4 Sep 2023

Viewed by 2738

Abstract

Biotic and abiotic factors influence the formation of fungal–algal pairings in lichen symbiosis. However, the specific determinants of these associations, particularly when distantly related fungi are involved, remain poorly understood. In this study, we investigated the impact of different drivers on the association [...] Read more.

Biotic and abiotic factors influence the formation of fungal–algal pairings in lichen symbiosis. However, the specific determinants of these associations, particularly when distantly related fungi are involved, remain poorly understood. In this study, we investigated the impact of different drivers on the association patterns between taxonomically diverse lichenized fungi and their trebouxioid symbiotic partners. We collected 200 samples from four biomes and identified 41 species of lichenized fungi, associating them with 16 species of trebouxioid green algae, of which 62% were previously unreported. The species identity of both the fungal and algal partners had the most significant effect on the outcome of the symbiosis, compared to abiotic factors like climatic variables and geographic distance. Some obviously specific associations were observed in the temperate zone; however, the nestedness value was lower in arid regions than in cold, polar, and temperate regions according to interaction network analysis. Cophylogenetic analyses revealed congruent phylogenies between trebouxioid algae and associated fungi, indicating a tendency to reject random associations. The main evolutionary mechanisms contributing to the observed phylogenetic patterns were “loss” and “failure to diverge” of the algal partners. This study broadens our knowledge of fungal–algal symbiotic patterns in view of Trebouxia-associated fungi. Full article

(This article belongs to the Special Issue Phylogeny and Taxonomy of Lichen Symbionts)

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17 pages, 3768 KiB

Open AccessArticle

Genome-Wide Identified MADS-Box Genes in Prunus campanulata ‘Plena’ and Theirs Roles in Double-Flower Development

by Chaoren Nie, Xiaoguo Xu, Xiaoqin Zhang, Wensheng Xia, Hongbing Sun, Na Li, Zhaoquan Ding and Yingmin Lv

Plants 2023, 12(17), 3171; https://doi.org/10.3390/plants12173171 - 4 Sep 2023

Cited by 4 | Viewed by 1531

Abstract

The MADS-box gene family plays key roles in flower induction, floral initiation, and floral morphogenesis in flowering plants. To understand their functions in the double-flower formation of Prunus campanulata ‘Plena’ (hereafter referred to as PCP), which is an excellent flowering cherry cultivar, we [...] Read more.

The MADS-box gene family plays key roles in flower induction, floral initiation, and floral morphogenesis in flowering plants. To understand their functions in the double-flower formation of Prunus campanulata ‘Plena’ (hereafter referred to as PCP), which is an excellent flowering cherry cultivar, we performed genome-wide identification of the MADS-box gene family. In this study, 71 MADS-box genes were identified and grouped into the Mα, Mβ, Mγ and MIKC subfamilies according to their structures and phylogenetic relationships. All 71 MADS-box genes were located on eight chromosomes of PCP. Analysis of the cis-acting elements in the promoter region of MADS-box genes indicated that they were associated mainly with auxin, abscisic acid, gibberellin, MeJA (methyl jasmonate), and salicylic acid responsiveness, which may be involved in floral development and differentiation. By observing the floral organ phenotype, we found that the double-flower phenotype of PCP originated from petaloid stamens. The analysis of MIKC-type MADS-box genes in PCP vegetative and floral organs by qRT–PCR revealed six upregulated genes involved in petal development and three downregulated genes participating in stamen identity. Comparative analysis of petaloid stamens and normal stamens also indicated that the expression level of the AG gene (PcMADS40) was significantly reduced. Thus, we speculated that these upregulated and downregulated genes, especially PcMADS40, may lead to petaloid stamen formation and thus double flowers. This study lays a theoretical foundation for MADS-box gene identification and classification and studying the molecular mechanism underlying double flowers in other ornamental plants. Full article

(This article belongs to the Special Issue Flower Germplasm Resource and Genetic Breeding)

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23 pages, 17336 KiB

Open AccessArticle

Genome-Wide Identification and Expression Analysis of RLCK-VII Subfamily Genes Reveal Their Roles in Stress Responses of Upland Cotton

by Yuhan Cen, Shiyi Geng, Linying Gao, Xinyue Wang, Xin Yan, Yuxia Hou and Ping Wang

Plants 2023, 12(17), 3170; https://doi.org/10.3390/plants12173170 - 4 Sep 2023

Viewed by 1574

Abstract

Receptor-like cytoplasmic kinase VII (RLCK-VII) subfamily members are vital players in plant innate immunity and are also involved in plant development and abiotic stress tolerance. As a widely cultivated textile crop, upland cotton (Gossypium hirsutum) attaches great importance to the cotton [...] Read more.

Receptor-like cytoplasmic kinase VII (RLCK-VII) subfamily members are vital players in plant innate immunity and are also involved in plant development and abiotic stress tolerance. As a widely cultivated textile crop, upland cotton (Gossypium hirsutum) attaches great importance to the cotton industry worldwide. To obtain details of the composition, phylogeny, and putative function of RLCK-VII genes in upland cotton, genome-wide identification, evolutionary event analysis, and expression pattern examination of RLCK-VII subfamily genes in G. hirsutum were performed. There are 129 RLCK-VII members in upland cotton (GhRLCKs) and they were divided into nine groups based on their phylogenetic relationships. The gene structure and sequence features are relatively conserved within each group, which were divided based on their phylogenetic relationships, and consistent with those in Arabidopsis. The phylogenetic analysis results showed that RLCK-VII subfamily genes evolved in plants before the speciation of Arabidopsis and cotton, and segmental duplication was the major factor that caused the expansion of GhRLCKs. The diverse expression patterns of GhRLCKs in response to abiotic stresses (temperature, salt, and drought) and V. dahliae infection were observed. The candidates that may be involved in cotton’s response to these stresses are highlighted. GhRLCK7 (GhRLCK7A and D), which is notably induced by V. dahliae infection, was demonstrated to positively regulate cotton defense against V. dahliae by the loss-of-function assay in cotton. These findings shed light on the details of the RLCK-VII subfamily in cotton and provide a scaffold for the further function elucidation and application of GhRLCKs for the germplasm innovation of cotton. Full article

(This article belongs to the Special Issue The Molecular Role of Plant Receptors in Resistance to Biotic Stress)

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9 pages, 307 KiB

Open AccessArticle

The Genus Sagina (Caryophyllaceae) in Italy: Nomenclatural Remarks

by Duilio Iamonico, Laura Guglielmone and Emanuele Del Guacchio

Plants 2023, 12(17), 3169; https://doi.org/10.3390/plants12173169 - 4 Sep 2023

Cited by 3 | Viewed by 1378

Abstract

A contribution to the nomenclature of the genus Sagina is presented. The following 10 taxa are recognized as being part of the Italian flora: S. alexandrae, S. apetala, S. glabra, S. maritima, S. micropetala, S. nodosa, S. [...] Read more.

A contribution to the nomenclature of the genus Sagina is presented. The following 10 taxa are recognized as being part of the Italian flora: S. alexandrae, S. apetala, S. glabra, S. maritima, S. micropetala, S. nodosa, S. pilifera, S. procumbens, S. revelierei, and S. saginoides subsp. saginoides. The names S. apetala var. decumbens (=S. apetala subsp. apetala), S. bryoides (=S. procumbens), S. patula (=S. apetala subsp. apetala), S. revelierei, Spergula glabra (=S. glabra), Spergula pilifera (=S. pilifera), and Spergella subulata var. macrocarpa (=S. saginoides subsp. saginoides) are here typified. Specimens deposited at B-W, C, E, and LY, and illustrations by Reichenbach were considered for the typifications. Specifically, two Reichenbach’s illustrations are chosen for S. bryoides and S. saginoides var. macrocarpa. A specimen at B-W is designated as the lectotype of S. glabra. Two specimens at C and G are designated as the lectotypes of S. apetala var. decumbens and S. revelierei, respectively. A specimen at LY is designated for S. patula. As we did not find original material, a neotype at G is designated for S. pilifera. Full article

(This article belongs to the Special Issue Taxonomy and Nomenclature of Caryophyllales)

18 pages, 2435 KiB

Open AccessArticle

Antioxidant, Anti-Inflammatory and Antiproliferative Effects of Osmanthus fragrans (Thunb.) Lour. Flower Extracts

by Steven Kuan-Hua Huang, Paolo Robert P. Bueno, Patrick Jay B. Garcia, Mon-Juan Lee, Kathlia A. De Castro-Cruz, Rhoda B. Leron and Po-Wei Tsai

Plants 2023, 12(17), 3168; https://doi.org/10.3390/plants12173168 - 4 Sep 2023

Cited by 1 | Viewed by 3672

Abstract

Osmanthus fragrans (Thunb.) Lour. flowers (OF-F) have been traditionally consumed as a functional food and utilized as folk medicine. This study evaluated the antioxidant, anti-inflammatory and cytotoxic effects of OF-F extracts on prostate cancer cells (DU-145) and determined possible protein-ligand interactions of its [...] Read more.

Osmanthus fragrans (Thunb.) Lour. flowers (OF-F) have been traditionally consumed as a functional food and utilized as folk medicine. This study evaluated the antioxidant, anti-inflammatory and cytotoxic effects of OF-F extracts on prostate cancer cells (DU-145) and determined possible protein-ligand interactions of its compounds in silico. The crude OF-F extracts—water (W) and ethanol (E) were tested for phytochemical screening, antioxidant, anti-inflammatory, and anti-cancer. Network and molecular docking analyses of chemical markers were executed to establish their application for anticancer drug development. OF-F-E possessed higher total polyphenols (233.360 ± 3.613 g/kg) and tannin (93.350 ± 1.003 g/kg) contents than OF-F-W. In addition, OF-F-E extract demonstrated effective DPPH scavenging activity (IC₅₀ = 0.173 ± 0.004 kg/L) and contained a high FRAP value (830.620 ± 6.843 g Trolox/kg). In cell culture experiments, OF-F-E significantly reduced NO levels and inhibited cell proliferation of RAW-264.7 and DU-145 cell lines, respectively. Network analysis revealed O. fragrans (Thunb.) Lour. metabolites could affect thirteen molecular functions and thirteen biological processes in four cellular components. These metabolites inhibited key proteins of DU-145 prostate cancer using molecular docking with rutin owning the highest binding affinity with PIKR31 and AR. Hence, this study offered a new rationale for O. fragrans (Thunb.) Lour. metabolites as a medicinal herb for anticancer drug development. Full article

(This article belongs to the Special Issue Plant Phytochemicals on Crop Protection and Drug Development)

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Cytotoxicity of O. fragrans (Thunb.) Lour. crude extracts. Values mean ± standard error of the mean (n = 3). Media with 0.5% DMSO and 5–flurouracil (5–FU) were used as negative and positive controls, respectively. Comparisons with 5–FU (***) p < 0.001. Full article ">Figure 2
(a) Gene set relationship between PRAD and selected O. fragrans (Thunb.) Lour. metabolites; (b) compound-target network, where PHI = phillygenin, LIG = ligustroside, VER = verbascoside, HPA = 4-hydroxyphenyl acetate, and RUT = rutin. Full article ">Figure 3
Protein-protein interaction network (PIN) of identified proteins. PIN of intersected genes set with interaction score at least 0.90 where red labelled proteins are top-ranking in interactivity. Full article ">Figure 4
(a–c) Gene ontology term and (d) KEGG pathway enrichment analysis of OFF metabolite targets to PRAD. Full article ">Figure 5
Molecular docking of OFF major metabolites and compound-target interactions. The protein-ligand complexes are (a) PIK3R1-rutin, (b) Grb2-verbascoside, (c) PDGFRB-ligustroside, and (d) AR-rutin. Full article ">

18 pages, 1517 KiB

Open AccessReview

Recent Updates on ALMT Transporters’ Physiology, Regulation, and Molecular Evolution in Plants

by Siarhei A. Dabravolski and Stanislav V. Isayenkov

Plants 2023, 12(17), 3167; https://doi.org/10.3390/plants12173167 - 4 Sep 2023

Cited by 3 | Viewed by 2024

Abstract

Aluminium toxicity and phosphorus deficiency in soils are the main interconnected problems of modern agriculture. The aluminium-activated malate transporters (ALMTs) comprise a membrane protein family that demonstrates various physiological functions in plants, such as tolerance to environmental Al³⁺ and the regulation of [...] Read more.

Aluminium toxicity and phosphorus deficiency in soils are the main interconnected problems of modern agriculture. The aluminium-activated malate transporters (ALMTs) comprise a membrane protein family that demonstrates various physiological functions in plants, such as tolerance to environmental Al³⁺ and the regulation of stomatal movement. Over the past few decades, the regulation of ALMT family proteins has been intensively studied. In this review, we summarise the current knowledge about this transporter family and assess their involvement in diverse physiological processes and comprehensive regulatory mechanisms. Furthermore, we have conducted a thorough bioinformatic analysis to decipher the functional importance of conserved residues, structural components, and domains. Our phylogenetic analysis has also provided new insights into the molecular evolution of ALMT family proteins, expanding their scope beyond the plant kingdom. Lastly, we have formulated several outstanding questions and research directions to further enhance our understanding of the fundamental role of ALMT proteins and to assess their physiological functions. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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Schematic representation of the domain arrangement in one AtALMT1 subunit. The TMD (transmembrane domain) contains six TMs (transmembrane helices I to VI); the CTD (C-terminal cytosolic domain) contains six Hs (α-helix bundles 1 to 6); and the magenta rectangle represents the fusaric acid resistance protein-like (pfam13515) domain. Full article ">Figure 2
The role of ALMTs in stomatal opening and closure. ALMT proteins are responsible for the influx/efflux of compounds (blue arrows); black arrows represent activation and blunt arrows represent inhibition, while the dotted arrow represents indirect regulation. ROS—reactive oxygen species, Mal2-—malate, ABA—abscisic acid, PP2C—protein phosphatases type 2C, MPKs—mitogen-activated protein kinases, GABA—γ-aminobutyric acid, CPKs—calcium-dependent kinases. Full article ">Figure 3
Schematic representation of STOP-mediated transcriptional regulation of target genes under Al stress and normal conditions. Genes responsible for early-phase Al response are depicted in a pink rectangle, and late-phase Al response genes are shown within a pale green rectangle. Regulators of STOP1 are depicted in a dark green rectangle. Black arrows represent activation, and blunt arrows represent inhibition. Full article ">Figure 4
Schematic model for the role of ALMT1 expression under low-Pi conditions. Under low-Pi and acidic conditions, Fe and Al accumulate in the cytoplasm, where they decrease the proteasomal degradation of STOP1, thereby promoting ALMT1 transcription. The tonoplast-located ALS2–STAR1 proteins transport Fe/Al to the vacuole, thus reducing their concentration in the cytosol and, subsequently, reducing STOP1 accumulation in the nucleus and ALMT1 transcription. ALMT1 exuded malate where it coupled with Fe and LOW PHOSPHATE ROOT 1 (LPR1); they generate ROS which inhibit cell wall expansion. Also, low Pi induced LPR1/2 expression, which converts Fe2+ to Fe3+. MEDIATOR 16 (MED16) interacted with STOP1 and linked with RNA polymerase II (RNA Pol II) to promote the expression of ALMT1 and malate efflux. The F-box protein Regulation of AtALMT1 Expression 1 (RAE1) interacted with STOP1 and promoted STOP1 ubiquitination and its further proteasomal degradation. At the same time, STOP1 promoted RAE1 transcription, thus creating a negative feedback loop between RAE1 and STOP1 (depicted in magenta arrows). Black arrows represent activation, blunt black arrows represent repression, dashed arrows represent transfer between compartments, and blue arrows indicate that the reaction involved other proteins. Full article ">

10 pages, 2013 KiB

Open AccessCommunication

OsGSTU17, a Tau Class Glutathione S-Transferase Gene, Positively Regulates Drought Stress Tolerance in Oryza sativa

by Jinyan Li, Lijun Meng, Shuohan Ren, Chunying Jia, Ruifang Liu, Hongzhen Jiang and Jingguang Chen

Plants 2023, 12(17), 3166; https://doi.org/10.3390/plants12173166 - 4 Sep 2023

Cited by 7 | Viewed by 1887

Abstract

As a great threat to the normal growth of rice, drought not only restricts the growth of rice, but also affects its yield. Glutathione S-transferases (GSTs) have antioxidant and detoxification functions. In rice, GSTs can not only effectively cope with biological stress, but [...] Read more.

As a great threat to the normal growth of rice, drought not only restricts the growth of rice, but also affects its yield. Glutathione S-transferases (GSTs) have antioxidant and detoxification functions. In rice, GSTs can not only effectively cope with biological stress, but also play a defense role against abiotic stress. In this study, we selected OsGSTU17, a member gene that was induced by drought, to explore the role of GSTs and analyze their physiological mechanisms that are involved in rice drought tolerance. With the CRISPR/Cas9 knockout system techniques, we obtained two independent mutant lines of osgstu17. After 14 days of drought stress treatment, and then re-supply of the water for 10 days, the survival rate of the osgstu17 mutant lines was significantly reduced compared to the wild-type (WT). Similarly, with the 10% (w/v) PEG6000 hydroponics experiment at the seedling stage, we also found that compared with the WT, the shoot and root biomass of osgstu17 mutant lines decreased significantly. In addition, both the content of the MDA and H₂O₂, which are toxic to plants, increased in the osgtu17 mutant lines. On the other hand, chlorophyll and proline decreased by about 20%. The activity of catalase and superoxide dismutase, which react with peroxides, also decreased by about 20%. Under drought conditions, compared with the WT, the expressions of the drought stress-related genes OsNAC10, OsDREB2A, OsAP37, OsP5CS1, OsRAB16C, OsPOX1, OsCATA, and OsCATB in the osgtu17 mutant lines were significantly decreased. Finally, we concluded that knocking out OsGSTU17 significantly reduced the drought tolerance of rice; OsGSTU17 could be used as a candidate gene for rice drought-tolerant cultivation. However, the molecular mechanism of OsGSTU17 involved in rice drought resistance needs to be further studied. Full article

(This article belongs to the Special Issue Cereal Crop Breeding)

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Quantitative assessment of the relative expression of OsGSTU17 during drought stress treatment was conducted using real-time RT-PCR. Rice seedlings were subjected to an initial growth period of 7 days in the regular IRRI solution, followed by transfer to a nutrient solution containing 10% (w/v) PEG6000 for varying durations. Subsequent RNA extraction was performed on distinct segments, namely (A) root and (B) shoot tissues of the Nipponbare rice cultivar. The error bars in the figures represent the standard error (SE) derived from triplicate analyses (n = 3 plants). The different letters indicate a significant difference between the treatments (p < 0.05, one-way ANOVA). Full article ">Figure 2
Drought stress sensitivity of osgstu17 mutant lines at the seedling stage. (A) Schematic diagram of the position of the target site (spacer) by CRISPR/Cas9-induced editing is shown on the OsGSTU17 gene structure. Sequencing outcomes of mutant alleles are aligned against the reference genome sequence, and the sizes of the insertions and/or deletions (In/Del) are indicated on the right. (B) Phenotype of drought-stressed plants followed by recovery. The seedlings were cultivated for a duration of 21 days under adequately irrigated conditions, employing a practice of accommodating 10 seedlings of uniform size per pot. Subsequently, irrigation was suspended for a span of 14 days, followed by a 10-day rehydration phase. A bar of 10 cm was utilized for scale reference. (C) Seedling survival. The count of seedlings that displayed at least one fully expanded leaf was recorded. The error bars in the figures depict the standard error (SE) derived from triplicate pots (n = 3 pots). The utilization of distinct letters signifies statistically significant disparities between the transgenic line and the wild type (WT) based on a significance level of p < 0.05, as determined by a one-way analysis of variance (ANOVA). Full article ">Figure 3
The biomass of osgstu17 mutant lines under control and drought stress conditions. Rice seedlings were cultivated in the standard IRRI solution for a period of 2 weeks, subsequent to which they were transplanted into a nutrient solution supplemented with 10% (w/v) PEG6000 for an additional 2-week duration. Phenotype of OsGSTU17 mutant lines grown in (A) control and (B) drought stress (10% PEG6000) conditions. Bar = 10 cm. (C) Root and (D) shoot biomass (dry weight) of plants grown in control and drought stress conditions. Error bars: SE (n = 4 plants). Varied letters denote a statistically significant distinction between the transgenic line and the WT as determined by a one-way analysis of variance (ANOVA) with a significance level of p < 0.05. Full article ">Figure 4
Physiological and biochemical changes in osgstu17 mutant lines. The growth conditions and treatment protocols remained consistent with the description provided in <a href="#plants-12-03166-f003" class="html-fig">Figure 3</a>. (A) The chlorophyll content, (B) proline content, (C) MDA content, (D) H2O2 content, (E) CAT activity and (F) SOD activity of osgstu17 mutant lines under control and drought stress. Error bars: SE (n = 4 plants). Varied letters denote a statistically significant distinction between the transgenic line and the WT as determined by a one-way analysis of variance (ANOVA) with a significance level of p < 0.05. Full article ">Figure 5
Transcript levels of stress-responsive genes in the osgstu17 mutant lines were assessed. The growth conditions and treatment protocols remained consistent with the description outlined in <a href="#plants-12-03166-f003" class="html-fig">Figure 3</a>. RNA extraction was carried out from the shoot tissues of seedlings subjected to (A) control and (B) drought stress conditions. The error bars depicted in the figures represent the standard error (SE) derived from triplicate plant samples (n = 3 plants). Varied letters indicate statistically significant distinctions between the transgenic line and the WT, as determined by an ANOVA with a significance level of p < 0.05. Full article ">

21 pages, 4034 KiB

Open AccessEditor’s ChoiceReview

In Vitro Cultivation and Ginsenosides Accumulation in Panax ginseng: A Review

by Fengjiao Xu, Anjali Kariyarath Valappil, Ramya Mathiyalagan, Thi Ngoc Anh Tran, Zelika Mega Ramadhania, Muhammad Awais and Deok Chun Yang

Plants 2023, 12(17), 3165; https://doi.org/10.3390/plants12173165 - 3 Sep 2023

Cited by 8 | Viewed by 3781

Abstract

The use of in vitro tissue culture for herbal medicines has been recognized as a valuable source of botanical secondary metabolites. The tissue culture of ginseng species is used in the production of bioactive compounds such as phenolics, polysaccharides, and especially ginsenosides, which [...] Read more.

The use of in vitro tissue culture for herbal medicines has been recognized as a valuable source of botanical secondary metabolites. The tissue culture of ginseng species is used in the production of bioactive compounds such as phenolics, polysaccharides, and especially ginsenosides, which are utilized in the food, cosmetics, and pharmaceutical industries. This review paper focuses on the in vitro culture of Panax ginseng and accumulation of ginsenosides. In vitro culture has been applied to study organogenesis and biomass culture, and is involved in direct organogenesis for rooting and shooting from explants and in indirect morphogenesis for somatic embryogenesis via the callus, which is a mass of disorganized cells. Biomass production was conducted with different types of tissue cultures, such as adventitious roots, cell suspension, and hairy roots, and subsequently on a large scale in a bioreactor. This review provides the cumulative knowledge of biotechnological methods to increase the ginsenoside resources of P. ginseng. In addition, ginsenosides are summarized at enhanced levels of activity and content with elicitor treatment, together with perspectives of new breeding tools which can be developed in P. ginseng in the future. Full article

(This article belongs to the Special Issue Production of Plant Secondary Metabolites Using Plant Tissue Culture and Bioreactor Culture Techniques)

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Figure 1
History of in vitro plant tissue culture of ginseng species. Note: This figure shows the in vitro cultivation of ginseng species from 1967 to present. Full article ">Figure 2
A summary of the standard procedures of P. ginseng’s in vitro culture methods and ways to increase ginsenosides accumulation. Note: The direct and indirect organogenesis methods can obtain the in vitro culture of P. ginseng. Likewise, the accumulation of ginsenosides can be acquired through the adventitious roots, cell suspension, and hairy root cultures. In addition, the large-scale culture in bioreactors treated with biotic and abiotic elicitors also increases the biomass and the ginsenosides accumulation. Full article ">Figure 3
Types of P. ginseng tissue culture. Note: (a) Callus (bar 1 cm) [<a href="#B32-plants-12-03165" class="html-bibr">32</a>], (b) somatic embryos (bar 1 mm) [<a href="#B33-plants-12-03165" class="html-bibr">33</a>], (c) shoots (bar 1 cm) [<a href="#B32-plants-12-03165" class="html-bibr">32</a>], (d) hairy roots (bar 820 μm) [<a href="#B34-plants-12-03165" class="html-bibr">34</a>], (e) cell suspension [<a href="#B35-plants-12-03165" class="html-bibr">35</a>], and (f) adventitious roots [<a href="#B36-plants-12-03165" class="html-bibr">36</a>]. Full article ">Figure 4
The protocol of somatic embryogenesis from callus to whole plants. Note: This figure shows the indirect organogenesis. First, the optimal callus was selected to form the embryogenic callus. In the next step of somatic embryogenesis, a regenerated whole plant can be obtained under optimal culture conditions. Full article ">Figure 5
The biosynthetic pathways of ginsenosides. Note: the two pathways are MVA and MEP, respectively; the three stages are the formation of IPP and DMAPP; IPP and DMAPP are converted into 2,3-oxidoSqualene; ginsenosides of dammarenediol type; PPD and PPT types are synthesized from 3 steps. The green color represents the related genes and enzymes. Full article ">

13 pages, 2039 KiB

Open AccessArticle

Preventing Overgrowth of Cucumber and Tomato Seedlings Using Difference between Day and Night Temperature in a Plant Factory with Artificial Lighting

by Young Ho Kim, Hwi Chan Yang, Yun Hyeong Bae, Soon Jae Hyeon, Seung Jae Hwang, Dea Hoon Kim and Dong Cheol Jang

Plants 2023, 12(17), 3164; https://doi.org/10.3390/plants12173164 - 3 Sep 2023

Cited by 2 | Viewed by 1806

Abstract

This study aimed to determine the feasibility of temperature difference as an overgrowth-prevention technique to influence plant height and internode length in a plant factory with artificial lighting. The control plants were grown in a commercial nursery greenhouse using a growth regulator (Binnari), [...] Read more.

This study aimed to determine the feasibility of temperature difference as an overgrowth-prevention technique to influence plant height and internode length in a plant factory with artificial lighting. The control plants were grown in a commercial nursery greenhouse using a growth regulator (Binnari), and +DIF (25 °C/15 °C), 0DIF (20 °C/20 °C), and −DIF (15 °C/25 °C) were the treatments with different day/night temperatures and the same average temperature (20 °C). Cucumbers showed the strongest suppression under the −DIF treatment, with a dwarfism rate of 33.3%. Similarly, tomatoes showed 0.8% and 22.2% inhibition in the 0DIF and −DIF treatments, respectively. The F_V/F_M of cucumber was approximately 0.81 for all treatments. The OJIP changes differed for cucumbers; however, both cucumbers and tomatoes had similar OJIP curve patterns and no abnormalities. The relative growth rate of cucumbers at the growth stage was 1.48 cm·cm·day⁻¹ for days 6–9 in +DIF stage 3, which was the highest growth rate among all treatments, and 0.71 cm·cm·day⁻¹ for days 3–6 in −DIF stage 1, which was the most growth-inhibited treatment. In tomatoes, we found that days 3–6 of −DIF stage 1 had the most growth inhibition at 0.45 cm·cm·day⁻¹. For cucumber, −DIF days 3–6 had the most growth inhibition, with a relative growth rate of 0.71 cm·cm·day⁻¹, but the fidelity was significantly higher than the other treatments, with a 171% increase. The same was true for tomatoes, with days 3–6 of −DIF stage 1 showing the most inhibited growth at 0.45 cm·cm·day⁻¹ but a 200% increase in fidelity. Therefore, applying the −DIF treatment at the beginning of growth would be most effective for both cucumbers and tomatoes to prevent overgrowth through the DIF in a plant factory with artificial lighting because it does not interfere with the seedling physiology and slows down the growth and development stage. Full article

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Root length (A), total root surface area (B), root average diameter (C), and total root volume (D) of cucumber and tomato in relation to the difference between day and night temperature. Significant differences between data are shown by different letters, p ≤ 0.05. Full article ">Figure 2
OJIP curves for cucumber (A) and tomato (B) grown under condition with a difference between day temperature and night temperature. +DIF: 25/15 °C (day/night); 0DIF 20/20 °C (day/night); −DIF 15/25 °C (day/night). Full article ">Figure 3
Growth stages of cucumber and tomato seedlings in DIF treatments and relative growth in plant height by day of treatment. (A) Relative growth rate of cucumber in 9 days before grafting; (B) relative growth rate of cucumber with +DIF treatment; (C) relative growth rate of cucumber with 0DIF treatment; (D) relative growth rate of cucumbers with −DIF treatment; (E) relative growth rate of tomato in 9 days before grafting; (F) relative growth rate of tomato with +DIF treatment; (G) relative growth rate of tomato with 0DIF treatment; (H) relative growth rate of tomato with −DIF treatment. Significant differences between data are shown by different letters, p ≤ 0.05. Full article ">Figure 4
Growth stages of cucumber and tomato seedlings in DIF treatments and compactness by day of treatment. (A) +DIF treatment; (B) 0DIF treatment; (C) −DIF treatment. Significant differences between data are shown by different letters, p ≤ 0.05. Full article ">Figure 5
Interior of the experimental plant factory with artificial lighting used in research. Growing cucumber (a) and tomato (b) using PFAL. Full article ">Figure 6
The day and night temperatures inside the plant factory with artificial lighting used in the study. Full article ">

16 pages, 2862 KiB

Open AccessArticle

Plant Growth Hormones and Micro-Tuberization in Breaking the Seed Dormancy of Bunium persicum (Boiss.) Fedts

by Mudasir Hafiz Khan, Niyaz Ahmad Dar, Bashir Ahmad Alie, Ghulam Hassan Mir, Uzma Fayaz, Azra Khan, Basharat Bashir, Ajaz Ahmad, Sheikh Mansoor, Yong Suk Chung and Seong Heo

Plants 2023, 12(17), 3163; https://doi.org/10.3390/plants12173163 - 3 Sep 2023

Viewed by 1659

Abstract

Bunium persicum is a valuable medicinal plant with limited production but high market demand. It thrives predominantly in high-altitude regions. The main challenges hindering its widespread cultivation are seed dormancy and a lengthy seed-to-seed cycle, making its large-scale cultivation difficult. Six genotypes of [...] Read more.

Bunium persicum is a valuable medicinal plant with limited production but high market demand. It thrives predominantly in high-altitude regions. The main challenges hindering its widespread cultivation are seed dormancy and a lengthy seed-to-seed cycle, making its large-scale cultivation difficult. Six genotypes of Bunium persicum were collected from different altitudes to evaluate its germination behavior and seed dormancy. The study was conducted during 2020–23 and comprised three experiments (viz., seed germination under an open field, controlled conditions, and micro-tuberization). Under open field conditions, germination percent was genotype dependent, and the highest germination percentage, root length, and shoot length were recorded in Shalimar Kalazeera-1. Germination behavior assessment of the Bunium persicum revealed that treatment T₉ (GA₃ (25 ppm) + TDZ (9 µM/L)) is effective in breaking the dormancy of Bunium persicum as well as in obtaining a higher germination percent for early development of the tubers. Similarly, with regard to the effect of temperature and moisture conditions, stratification under moist chilling conditions showed effectiveness in breaking seed dormancy as the germination percentage in stratified seeds was at par with the most efficient growth hormone. With regard to the in vitro micro-propagation, direct regeneration showed multiple shoot primordia at the base of the tubers without intervening callus phase from the MS medium supplemented with BA (22.2 µM) and NAA (13.95 µM) 4 weeks after sub-culturing. Similarly, medium supplemented with JA (8.0 mg/L) and BA (22.2 µM) produced well-organized somatic embryos with shiny surfaces, which appeared at the swelled basal portion of apical stems. Further, the combination of JA (6.0 mg/L) and BA (22.2 M) was effective in developing the micro-tubers and also enhanced the weight and length of Bunium persicum micro-tubers. Full article

(This article belongs to the Special Issue Plant Growth Promoters: The Eliciting Role of Recycled Biomasses)

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Seedling and tuber development of Bunium persicum under field conditions. Full article ">Figure 2
Influence of PGRs on seed germination of Bunium persicum. Full article ">Figure 3
Germination behavior of Bunium persicum genotypes under controlled conditions. Full article ">Figure 4
Tuber development of Bunium persicum under field conditions: (a) seed germination under pot culture; (b) nursery development of 14 treatments; (c) tuber development after 3 years; and (d) treatment effect on tuber development. Full article ">Figure 5
Shoot parameters as affected by PGR treatments under in vitro conditions. Full article ">Figure 6
Different stages of micro-tuber development in Bunium persicum (a) green tip of apical stem; (b) middle portion of apical stem; (c,d) swollen basal part of apical stems; (e) micro-tubers. Full article ">Figure 7
Experimental site. Full article ">

12 pages, 3253 KiB

Open AccessArticle

Virus-Induced Gene Silencing in the Tea Plant (Camellia sinensis)

by Wei Yang, Xianya Chen, Jiahao Chen, Peng Zheng, Shaoqun Liu, Xindong Tan and Binmei Sun

Plants 2023, 12(17), 3162; https://doi.org/10.3390/plants12173162 - 3 Sep 2023

Cited by 8 | Viewed by 2497

Abstract

The recent availability of a number of tea plant genomes has sparked substantial interest in using reverse genetics to explore gene function in tea (Camellia sinensis). However, a hurdle to this is the absence of an efficient transformation system, and virus-induced [...] Read more.

The recent availability of a number of tea plant genomes has sparked substantial interest in using reverse genetics to explore gene function in tea (Camellia sinensis). However, a hurdle to this is the absence of an efficient transformation system, and virus-induced gene silencing (VIGS), a transient transformation system, could be an optimal choice for validating gene function in the tea plant. In this study, phytoene desaturase (PDS), a carotenoid biosynthesis gene, was used as a reporter to evaluate the VIGS system. The injection sites of the leaves (leaf back, petiole, and stem) for infiltration were tested, and the results showed that petiole injection had the most effective injection, without leading to necrotic lesions that cause the leaves to drop. Tea leaves were inoculated with Agrobacterium harboring a tobacco rattle virus plasmid (pTRV2) containing a CsPDS silencing fragment. The tea leaves exhibited chlorosis symptoms 7–14 days after inoculation, depending on the cultivar. In the chlorosis plants, the coat protein (CP) of tobacco rattle virus (TRV) was detected and coincided with the lower transcription of CsPDS and reduced chlorophyll content compared with the empty vector control, with 81.82% and 54.55% silencing efficiency of ‘LTDC’ and ‘YSX’, respectively. These results indicate that the VIGS system with petiole injection could quickly and effectively silence a gene in tea plants. Full article

(This article belongs to the Section Plant Molecular Biology)

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Conserved domains of CsPDS. The red boxes indicate the conserved domains of the PDS superfamily, and the * indicated singular ten number of amino acid sequence. The PDS sequences of Actinidia chinensis var. chinensis, Arabidopsis thaliana, Oryza sativa L., and Vitis vinifera L. were downloaded from NCBI (<a href="https://www.ncbi.nlm.nih.gov" target="_blank">https://www.ncbi.nlm.nih.gov</a>). Full article ">Figure 2
Schematic of pTRV2-CsPDS vector construction. (a) Map of pTRV1, pTRV2, and pTRV2-CsPDS vectors. LB, left border; RB, right border; 2 × 35S, two consecutive 35S promoters; RdRp, RNA-dependent RNA polymerase; MP, movement protein; 16K, 16 kD protein; Rz, self-cleaving ribozyme; NOSt, NOS terminator; CP, coat protein; and MCS, multiple cloning site. (b) Schematic of the construction process. (c) PCR amplification of the CsPDS silencing gene fragment (SGF) in the empty and recombinant plasmid. Full article ">Figure 3
Silencing of phytoene desaturase (PDS) in Camellia sinensis L. (a) Injection sites indicated. Red arrow for petiole injection; blue arrow stem for injection; black arrow for leaf back injection; (b) chlorosis symptom in ‘YSX’ leaves after treatment with pTRV1+pTRV2-CsPDS and the controls; nondestructive evaluation of chlorophyll content using a SPAD-502 plus chlorophyll meter on infected leaves of ‘LTDC’ on the seventh day after injection (DAI) (c) and ‘TSX’ 14 DAI (d). Statistical analyses to compare the plants were carried out with the least significant difference (LSD) test (** p < 0.01). Data are presented as the mean ± SD (n = 3); silencing efficiency in ‘LTDC’ and ‘YSX’ (e); (f) detection of tobacco rattle virus (TRV) fragments after virus-induced gene silencing (VIGS) treatments. Full article ">Figure 4
Evaluation of virus-induced gene silencing (VIGS) of phytoene desaturase (PDS) using petiole injection in tea leaves. Chlorosis symptoms after VIGS of CsPDS in ‘LTDC’ on the seventh day after injection (DAI) (a) and ‘YSX’ on the fourteenth DAI (f); each of 11 tea plants from ‘LTDC’ and ‘YSX’ were infected, named PDS1-PDS11, respectively, and (a,e) only presented the leaves of a single plant with chlorosis symptoms. Relative expression of CsPDS in ‘LTDC’ (b) and ‘YSX’ (g); total chlorophyll, chlorophyll a, and chlorophyll b contents in the VIGS-treated leaves of ‘LTDC’ (c–e) and ‘YSX’ (h–j). Statistical analyses to compare the plants were carried out with the least significant difference (LSD) test (* p < 0.05 and ** p < 0.01). Data are presented as the mean ± SD (n = 3). Full article ">

15 pages, 2520 KiB

Open AccessArticle

Ribonucleotide and R-Loop Damage in Plastid DNA and Mitochondrial DNA during Maize Development

by Diwaker Tripathi, Delene J. Oldenburg and Arnold J. Bendich

Plants 2023, 12(17), 3161; https://doi.org/10.3390/plants12173161 - 2 Sep 2023

Viewed by 1427

Abstract

Although the temporary presence of ribonucleotides in DNA is normal, their persistence represents a form of DNA damage. Here, we assess such damage and damage defense to DNA in plastids and mitochondria of maize. Shoot development proceeds from meristematic, non-pigmented cells containing proplastids [...] Read more.

Although the temporary presence of ribonucleotides in DNA is normal, their persistence represents a form of DNA damage. Here, we assess such damage and damage defense to DNA in plastids and mitochondria of maize. Shoot development proceeds from meristematic, non-pigmented cells containing proplastids and promitochondria at the leaf base to non-dividing green cells in the leaf blade containing mature organelles. The organellar DNAs (orgDNAs) become fragmented during this transition. Previously, orgDNA damage and damage defense of two types, oxidative and glycation, was described in maize, and now a third type, ribonucleotide damage, is reported. We hypothesized that ribonucleotide damage changes during leaf development and could contribute to the demise of orgDNAs. The levels of ribonucleotides and R-loops in orgDNAs and of RNase H proteins in organelles were measured throughout leaf development and in leaves grown in light and dark conditions. The data reveal that ribonucleotide damage to orgDNAs increased by about 2- to 5-fold during normal maize development from basal meristem to green leaf and when leaves were grown in normal light conditions compared to in the dark. During this developmental transition, the levels of the major agent of defense, RNase H, declined. The decline in organellar genome integrity during maize development may be attributed to oxidative, glycation, and ribonucleotide damages that are not repaired. Full article

(This article belongs to the Special Issue DNA Damage and Repair Response in Plants)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
R-loop levels in orgDNA during maize development. Plastid (a) and mitochondrial (b) DNAs from Stalk lower (S1), Stalk upper (S2), and L1 (first leaf) were isolated, spotted onto nylon membranes, and probed with R-loop antibodies. Signal intensity was measured following detection using NBT/BCIP reagents. The orgDNA was assayed using dsDNA antibodies and similar detection procedures. The integrated density of each dot blot was determined using ImageJ. The ordinate shows the R-loop/dsDNA signal normalized to the tissue with the lowest value (Stalk lower), which is set at one. For the data in <a href="#plants-12-03161-f001" class="html-fig">Figure 1</a>, <a href="#plants-12-03161-f002" class="html-fig">Figure 2</a>, <a href="#plants-12-03161-f003" class="html-fig">Figure 3</a>, <a href="#plants-12-03161-f004" class="html-fig">Figure 4</a>, <a href="#plants-12-03161-f005" class="html-fig">Figure 5</a> and <a href="#plants-12-03161-f006" class="html-fig">Figure 6</a>, all assays were performed at least three times. The statistically significant differences were measured using ANOVA statistic test with post hoc analysis using Tukey’s HSD and are shown as asterisks, where *** p-value ≤ 0.001. Full article ">Figure 2
R-loop levels in orgDNA from maize seedling grown under light and dark conditions. Plastid (a) and mitochondrial (b) DNAs from total leaf tissues of seedlings grown in light and dark were isolated and spotted onto membranes. The membranes were probed with R-loop antibodies and signal intensity was measured following detection using NBT/BCIP reagents. OrgDNA in each dot was determined using dsDNA antibodies and similar detection procedures. The integrated density of each dot blot was determined using ImageJ. The ratio of integrated density of R-loop/dsDNA signal was normalized to the tissue with the lowest value (Dark-grown leaves), which is set at one. The statistically significant differences were measured using ANOVA statistic test with post hoc analysis using Tukey’s HSD and are shown as asterisks, where *** p-value ≤ 0.001. Full article ">Figure 3
rNMP levels in orgDNA during maize development. Plastid (a,c) and mitochondrial (b,d) DNAs from Stalk lower, Stalk upper, and L1 were isolated and treated with RNase H1 (a,b) and RNase H2 (c,d) to remove ribonucleotides at RNA/DNA hybrid regions. Labeling of regions where rNMPs were removed was carried out using DNA Pol I and DIG-dUTP, and this was also conducted for orgDNA without RNase H treatment. The ratio of the integrated density of +RNase H/–RNase H signal was normalized to the tissue with the lowest value (Stalk lower), which is set at one. The statistically significant differences were measured using ANOVA statistic test with post hoc analysis using Tukey’s HSD and are shown as asterisks, where ** p-value ≤ 0.01, *** p-value ≤ 0.001. Full article ">Figure 4
rNMP levels in orgDNA from maize seedling grown under light and dark conditions. Plastid (a) and mitochondrial (b) DNAs from total leaf tissues of seedlings grown in light and dark were isolated and treated with RNase H1 (a,b) or RNase H2 (c,d) to remove ribonucleotides at RNA/DNA hybrid regions (as described for <a href="#plants-12-03161-f003" class="html-fig">Figure 3</a>). The integrated density of each dot blot was determined using ImageJ. The ratio of +RNase H/–RNase H signal was normalized to the tissue with the lowest value (dark-grown leaves). The statistically significant differences were measured using ANOVA statistic test with post hoc analysis using Tukey’s HSD and are shown as asterisks, where *** p-value ≤ 0.001. Full article ">Figure 5
Measurement of RNase H1 (a,b) and RNase H2A (c,d) protein levels in organelles during maize development. Plastid (a) and mitochondrial (b) proteins from Stalk lower, Stalk upper, and L1 were isolated and spotted to nitrocellulose membranes, and then probed with either RNase H1 (a,b) or RNase H2A (c,d) antibodies. The ratio of integrated signal density was normalized to the tissue with the lowest value (L1), which is set at one. The statistically significant differences were measured using ANOVA statistic test with post hoc analysis using Tukey’s HSD and are shown as asterisks, where ** p-value ≤ 0.01, *** p-value ≤ 0.001. Full article ">Figure 6
Measurement of RNase H1 (a,b) and RNase H2A (c,d) protein levels in organelles from maize seedlings grown under light and dark conditions. Plastid (a,c) and mitochondrial (b,d) proteins from total leaf tissues of seedlings grown in light and dark were isolated and probed with RNase H1 (a,b) and RNase H2A (c,d) antibodies. The signals were normalized to the tissue with the lowest value (dark-grown leaves), as in <a href="#plants-12-03161-f005" class="html-fig">Figure 5</a>. The statistically significant differences were measured using ANOVA statistic test with post hoc analysis using Tukey’s HSD and are shown as asterisks, where *** p-value ≤ 0.001. Full article ">

18 pages, 3211 KiB

Open AccessArticle

Melatonin Reverses High-Temperature-Stress-Inhibited Photosynthesis in the Presence of Excess Sulfur by Modulating Ethylene Sensitivity in Mustard

by Noushina Iqbal, Zebus Sehar, Mehar Fatma, Sheen Khan, Ameena Fatima Alvi, Iqbal R. Mir, Asim Masood and Nafees A. Khan

Plants 2023, 12(17), 3160; https://doi.org/10.3390/plants12173160 - 2 Sep 2023

Cited by 5 | Viewed by 1407

Abstract

Melatonin is a pleiotropic, nontoxic, regulatory biomolecule with various functions in abiotic stress tolerance. It reverses the adverse effect of heat stress on photosynthesis in plants and helps with sulfur (S) assimilation. Our research objective aimed to find the influence of melatonin, along [...] Read more.

Melatonin is a pleiotropic, nontoxic, regulatory biomolecule with various functions in abiotic stress tolerance. It reverses the adverse effect of heat stress on photosynthesis in plants and helps with sulfur (S) assimilation. Our research objective aimed to find the influence of melatonin, along with excess sulfur (2 mM SO₄²⁻), in reversing heat stress’s impacts on the photosynthetic ability of the mustard (Brassica juncea L.) cultivar SS2, a cultivar with low ATP-sulfurylase activity and a low sulfate transport index (STI). Further, we aimed to substantiate that the effect was a result of ethylene modulation. Melatonin in the presence of excess-S (S) increased S-assimilation and the STI by increasing the ATP-sulfurylase (ATP-S) and serine acetyltransferase (SAT) activity of SS2, and it enhanced the content of cysteine (Cys) and methionine (Met). Under heat stress, melatonin increased S-assimilation and diverted Cys towards the synthesis of more reduced glutathione (GSH), utilizing excess-S at the expense of less methionine and ethylene and resulting in plants’ reduced sensitivity to stress ethylene. The treatment with melatonin plus excess-S increased antioxidant enzyme activity, photosynthetic-S use efficiency (p-SUE), Rubisco activity, photosynthesis, and growth under heat stress. Further, plants receiving melatonin and excess-S in the presence of norbornadiene (NBD; an ethylene action inhibitor) under heat stress showed an inhibited STI and lower photosynthesis and growth. This suggested that ethylene was involved in the melatonin-mediated heat stress reversal effects on photosynthesis in plants. The interaction mechanism between melatonin and ethylene is still elusive. This study provides avenues to explore the melatonin–ethylene-S interaction for heat stress tolerance in plants. Full article

(This article belongs to the Special Issue Amino Acid-Originated Growth Regulators: Functions and Regulation of Plant Developmental Responses under Changing Environmental Conditions)

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14 pages, 1839 KiB

Open AccessArticle

Soil Contamination with Europium Induces Reduced Oxidative Damage in Hordeum vulgare Grown in a CO₂-Enriched Environment

by Hanaa E. A. Amer, Hamada AbdElgawad, Mahmoud M. Y. Madany, Ahmed M. A. Khalil and Ahmed M. Saleh

Plants 2023, 12(17), 3159; https://doi.org/10.3390/plants12173159 - 2 Sep 2023

Viewed by 1408

Abstract

The extensive and uncontrolled utilization of rare earth elements, like europium (Eu), could lead to their accumulation in soils and biota. Herein, we investigated the impact of Eu on the growth, photosynthesis, and redox homeostasis in barley and how that could be affected [...] Read more.

The extensive and uncontrolled utilization of rare earth elements, like europium (Eu), could lead to their accumulation in soils and biota. Herein, we investigated the impact of Eu on the growth, photosynthesis, and redox homeostasis in barley and how that could be affected by the future CO₂ climate (eCO₂). The plants were exposed to 1.09 mmol Eu³⁺/kg soil under either ambient CO₂ (420 ppm, aCO₂) or eCO₂ (620 ppm). The soil application of Eu induced its accumulation in the plant shoots and caused significant reductions in biomass- and photosynthesis-related parameters, i.e., chlorophyll content, photochemical efficiency of PSII, Rubisco activity, and photosynthesis rate. Further, Eu induced oxidative stress as indicated by higher levels of H₂O₂ and lipid peroxidation products, and lower ASC/DHA and GSH/GSSG ratios. Interestingly, the co-application of eCO₂ significantly reduced the accumulation of Eu in plant tissues. Elevated CO₂ reduced the Eu-induced oxidative damage by supporting the antioxidant defense mechanisms, i.e., ROS-scavenging molecules (carotenoids, flavonoids, and polyphenols), enzymes (CAT and peroxidases), and ASC-GSH recycling enzymes (MDHAR and GR). Further, eCO₂ improved the metal detoxification capacity by upregulating GST activity. Overall, these results provide the first comprehensive report for Eu-induced oxidative phytotoxicity and how this could be mitigated by eCO₂. Full article

(This article belongs to the Collection Feature paper in Plant Response to Abiotic Stress and Climate Change)

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Figure 1
Effect of Eu, elevated CO2 (eCO2), and their combination (Eu + eCO2) on the fresh (A) and dry (B) biomasses of 28-day old H. vulgare plants. Each value represents the mean of five independent replicates and the vertical bars represent the standard error. Different lower-case letters on the bars, within the same graph, indicate significant difference at the 0.05 probability level as indicated by Tukey’s multiple range tests. Full article ">Figure 2
Effect of Eu, elevated CO2 (eCO2), and their combination (Eu + eCO2) on the photosynthesis-related parameters of 28-day old H. vulgare plants. (A): chlorophyll a; (B): chlorophyll b; (C): chlorophyll a + b; (D): carotenoids; (E): chlorophyll fluorescence; (F): stomatal conductance; (G): Rubisco activity; (H): rate of photosynthesis. Each value represents the mean of five independent replicates and the vertical bars represent the standard error. Different lower-case letters on the bars, within the same graph, indicate significant difference at the 0.05 probability level as indicated by Tukey’s multiple range tests. Full article ">Figure 3
Effect of Eu, elevated CO2 (eCO2), and their combination (Eu + eCO2) on the activity of antioxidant enzymes in the shoots of 28-day old H. vulgare plants. (A): SOD, superoxide dismutase; (B): CAT, catalase, (C): POX, peroxidase; (D): APX, ascorbate peroxidase, (E): DHAR, dehydroascorbate reductase; (F): MDHAR, monodehydroascorbate reductase; (G): GPX, glutathione peroxidase; (H): GR, glutathione reductase. Each value represents the mean of five independent replicates and the vertical bars represent the standard error. Different lower-case letters on the bars, within the same graph, indicate significant difference at the 0.05 probability level as indicated by Tukey’s multiple range tests. Full article ">Figure 4
Effect of Eu, elevated CO2 (eCO2), and their combination (Eu + eCO2) on the levels of metabolites of glutathione-ascorbate cycle in the shoots of 28-day old H. vulgare plants. (A): ASC, reduced ascorbate; (B): DHA, oxidized ascorbate; (C): TASC, total ascorbate; (D): ASC/DHA ratio; (E): GSH, reduced glutathione; (F): GSSG, oxidized glutathione; (G): TGSH, total glutathione; (H): GSH/GSSG ratio. Each value represents the mean of five independent replicates and the vertical bars represent the standard error. Different lower-case letters on the bars, within the same graph, indicate significant difference at the 0.05 probability level as indicated by Tukey’s multiple range tests. Full article ">

15 pages, 3876 KiB

Open AccessArticle

Phytochemical Cue for the Fitness Costs of Herbicide-Resistant Weeds

by Hong-Yu Li, Yan Guo, Bo-Yan Jin, Xue-Fang Yang and Chui-Hua Kong

Plants 2023, 12(17), 3158; https://doi.org/10.3390/plants12173158 - 2 Sep 2023

Cited by 1 | Viewed by 1373

Abstract

Despite increasing knowledge of the fitness costs of viability and fecundity involved in the herbicide-resistant weeds, relatively little is known about the linkage between herbicide resistance costs and phytochemical cues in weed species and biotypes. This study demonstrated relative fitness and phytochemical responses [...] Read more.

Despite increasing knowledge of the fitness costs of viability and fecundity involved in the herbicide-resistant weeds, relatively little is known about the linkage between herbicide resistance costs and phytochemical cues in weed species and biotypes. This study demonstrated relative fitness and phytochemical responses in six herbicide-resistant weeds and their susceptible counterparts. There were significant differences in the parameters of viability (growth and photosynthesis), fecundity fitness (flowering and seed biomass) and a ubiquitous phytochemical (–)-loliolide levels between herbicide-resistant weeds and their susceptible counterparts. Fitness costs occurred in herbicide-resistant Digitaria sanguinalis and Leptochloa chinensis but they were not observed in herbicide-resistant Alopecurus japonicas, Eleusine indica, Ammannia arenaria, and Echinochloa crus-galli. Correlation analysis indicated that the morphological characteristics of resistant and susceptible weeds were negatively correlated with (–)-loliolide concentration, but positively correlated with lipid peroxidation malondialdehyde and total phenol contents. Principal component analysis showed that the lower the (–)-loliolide concentration, the stronger the adaptability in E. crus-galli and E. indica. Therefore, not all herbicide-resistant weeds have fitness costs, but the findings showed several examples of resistance leading to improved fitness even in the absence of herbicides. In particular, (–)-loliolide may act as a phytochemical cue to explain the fitness cost of herbicide-resistant weeds by regulating vitality and fecundity. Full article

(This article belongs to the Special Issue Sustainable Weed Management II)

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15 pages, 5203 KiB

Open AccessArticle

Identification of Differentially Expressed lncRNAs in Response to Blue Light and Expression Pattern Analysis of Populus tomentosa Hybrid Poplar 741

by Hongyan Li, Yiwen Zhang, Jinping Lan, Shijie Wang, Hongyu Cai, Xin Meng, Yachao Ren and Minsheng Yang

Plants 2023, 12(17), 3157; https://doi.org/10.3390/plants12173157 - 2 Sep 2023

Viewed by 1179

Abstract

Poplar is an important shelterbelt, timber stand, and city tree species that has been the focus of forestry research. The regulatory role of the long non-coding RNA molecule (lncRNA; length > 200 nt) has been a research hotspot in plants. In this study, [...] Read more.

Poplar is an important shelterbelt, timber stand, and city tree species that has been the focus of forestry research. The regulatory role of the long non-coding RNA molecule (lncRNA; length > 200 nt) has been a research hotspot in plants. In this study, seedlings of 741 poplar were irradiated with LED blue and white light, and the Illumina HiSeq 2000 sequencing platform was used to identify lncRNAs. |logFC| > 1 and p < 0.05 were considered to indicate differentially expressed lncRNAs, and nine differentially expressed lncRNAs were screened, the target genes of which were predicted, and three functionally annotated target genes were obtained. The differentially expressed lncRNAs were identified as miRNA targets. Six lncRNAs were determined to be target sites for twelve mRNAs in six miRNA families. LncRNAs and their target genes, including lncRNA MSTRG.20413.1-ptc-miR396e-5p-GRF9, were verified using quantitative real-time polymerase chain reaction analysis, and the expression patterns were analyzed. The analysis showed that the ptc-miR396e-5p expression was downregulated, while lncRNA MSTRG.20413.1 and GRF9 expression was upregulated, after blue light exposure. These results indicate that lncRNAs interact with miRNAs to regulate gene expression and affect plant growth and development. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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Figure 1
Global data analysis of mRNA and lncRNA expression under different light types in 741 poplar. (a) Two types of transcript length distribution plots; (b) distribution graph of different databases used for predicting coded transcripts. Full article ">Figure 2
Identification of differentially expressed lncRNAs under blue-white light. (a) Numbers of differentially expressed lncRNAs; (b) Venn diagram of differentially expressed lncRNAs. Full article ">Figure 3
GO annotation of differentially expressed lncRNAs target genes. Full article ">Figure 4
Differential lncRNA expression patterns. Full article ">Figure 5
Differentially expressed lncRNA target gene expression patterns. Full article ">Figure 6
Expression pattern analysis of the lncRNA MSTRG.20413.1, ptc-miR396e-5p and GRF9. Full article ">Figure 7
Western blot to detect GRF protein expression. * 0.01 < p ≤ 0.05. Full article ">

23 pages, 6921 KiB

Open AccessArticle

Genomic and Transcriptional Profiling Analysis and Insights into Rhodomyrtone Yield in Rhodomyrtus tomentosa (Aiton) Hassk

by Alisa Nakkaew, Thipphanet Masjon and Supayang Piyawan Voravuthikunchai

Plants 2023, 12(17), 3156; https://doi.org/10.3390/plants12173156 - 1 Sep 2023

Viewed by 1218

Abstract

Rhodomyrtus tomentosa is a source of a novel antibiotic, rhodomyrtone. Because of the increasing industrial demand for this compound, germplasm with a high rhodomyrtone content is the key to sustainable future cultivation. In this study, rhodomyrtone genotypes were verified using the plastid genomic [...] Read more.

Rhodomyrtus tomentosa is a source of a novel antibiotic, rhodomyrtone. Because of the increasing industrial demand for this compound, germplasm with a high rhodomyrtone content is the key to sustainable future cultivation. In this study, rhodomyrtone genotypes were verified using the plastid genomic region marker matK and nuclear ribosomal internal transcribed spacer ITS. These two DNA barcodes proved to be useful tools for identifying different rhodomyrtone contents via the SNP haplotypes C569T and A561G, respectively. The results were correlated with rhodomyrtone content determined via HPLC. Subsequently, R. tomentosa samples with high- and low-rhodomyrtone genotypes were collected for de novo transcriptome and gene expression analyses. A total of 83,402 unigenes were classified into 25 KOG classifications, and 74,102 annotated unigenes were obtained. Analysis of differential gene expression between samples or groups using DESeq2 revealed highly expressed levels related to rhodomyrtone content in two genotypes. semiquantitative RT-PCR further revealed that the high rhodomyrtone content in these two genotypes correlated with expression of zinc transporter protein (RtZnT). In addition, we found that expression of RtZnT resulted in increased sensitivity of R. tomentosa under ZnSO₄ stress. The findings provide useful information for selection of cultivation sites to achieve high rhodomyrtone yields in R. tomentosa. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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19 pages, 1444 KiB

Open AccessArticle

Seasonal Variation in Cell Wall Composition and Carbohydrate Metabolism in the Seagrass Posidonia oceanica Growing at Different Depths

by Marwa Ismael, Quentin Charras, Maïté Leschevin, Damien Herfurth, Romain Roulard, Anthony Quéro, Christine Rusterucci, Jean-Marc Domon, Colette Jungas, Wilfred Vermerris and Catherine Rayon

Plants 2023, 12(17), 3155; https://doi.org/10.3390/plants12173155 - 1 Sep 2023

Cited by 1 | Viewed by 1452

Abstract

Posidonia oceanica is a common seagrass in the Mediterranean Sea that is able to sequester large amounts of carbon. The carbon assimilated during photosynthesis can be partitioned into non-structural sugars and cell-wall polymers. In this study, we investigated the distribution of carbon in [...] Read more.

Posidonia oceanica is a common seagrass in the Mediterranean Sea that is able to sequester large amounts of carbon. The carbon assimilated during photosynthesis can be partitioned into non-structural sugars and cell-wall polymers. In this study, we investigated the distribution of carbon in starch, soluble carbohydrates and cell-wall polymers in leaves and rhizomes of P. oceanica. Analyses were performed during summer and winter in meadows located south of the Frioul archipelago near Marseille, France. The leaves and rhizomes were isolated from plants collected in shallow (2 m) and deep water (26 m). Our results showed that P. oceanica stores more carbon as starch, sucrose and cellulose in summer and that this is more pronounced in rhizomes from deep-water plants. In winter, the reduction in photoassimilates was correlated with a lower cellulose content, compensated with a greater lignin content, except in rhizomes from deep-water plants. The syringyl-to-guaiacyl (S/G) ratio in the lignin was higher in leaves than in rhizomes and decreased in rhizomes in winter, indicating a change in the distribution or structure of the lignin. These combined data show that deep-water plants store more carbon during summer, while in winter the shallow- and deep-water plants displayed a different cell wall composition reflecting their environment. Full article

(This article belongs to the Collection Feature Papers in Plant Physiology and Metabolism)

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Starch content (A) and amylase activity (B) in leaves and rhizomes from P. oceanica harvested in summer and winter at water depths of 2 and 26 m. Data are means ± SD (n = 3). The different letters indicate significant differences (p ≤ 0.05) between the seasons and the depth of sampling according to Kruskal-Wallis test. DM: dry mass. FM: fresh mass. Full article ">Figure 2
Soluble carbohydrate content in leaves and rhizomes from P. oceanica harvested in summer and winter at water depths of 2 and 26 m. (A) Sucrose, (B) glucose, (C) fructose. Data are means ± SD (n = 3). Different letters indicate statistically significant differences between samples from different seasons and/or depths of sampling (p ≤ 0.05) according to Kruskal-Wallis test. DM: dry mass. Full article ">Figure 3
Cinnamyl alcohol dehydrogenase (CAD) enzyme activity assays in leaves and rhizomes from P. oceanica harvested in summer and winter at water depths of 2 and 26 m., Data are means ± SD (n = 3). The means marked with different letters indicate statistically significant differences between the seasons and the depths of sampling, (p ≤ 0.05) according to Kruskal-Wallis test. FM: fresh mass. Full article ">Figure 4
The carbon profile in P. oceanica meadows according to their leaves, rhizomes, the season and depth. The leaves and rhizomes studied are surrounded by a rectangle. The arrows and the tables show the significant changes in the study parameters between the two different depths and seasons, respectively. The color of the arrows and tables correspond to the study parameters as shown above. The direction of the arrows presents the changes in the parameters between the two different depths. The upward-pointing arrows mean levels are higher in shallow water. The downward-pointing arrows indicate higher levels in deep water. +: high amount in summer compared to winter, -: low amount in summer compared to winter. NS: non-significant. Full article ">

15 pages, 11986 KiB

Open AccessArticle

Phylogenetic Analysis of the PR-4 Gene Family in Euphorbiaceae and Its Expression Profiles in Tung Tree (Vernicia fordii)

by Chengbo Yang, Yaqi Yi, Jiabei Wang, Liu Ge, Lin Zhang and Meilan Liu

Plants 2023, 12(17), 3154; https://doi.org/10.3390/plants12173154 - 1 Sep 2023

Viewed by 1185

Abstract

Pathogenesis-related protein-4 (PR-4) is generally believed to be involved in physiological processes. However, a comprehensive investigation of this protein in tung tree (Vernicia fordii) has yet to be conducted. In this study, we identified 30 PR-4 genes in the [...] Read more.

Pathogenesis-related protein-4 (PR-4) is generally believed to be involved in physiological processes. However, a comprehensive investigation of this protein in tung tree (Vernicia fordii) has yet to be conducted. In this study, we identified 30 PR-4 genes in the genomes of Euphorbiaceae species and investigated their domain organization, evolution, promoter cis-elements, expression profiles, and expression profiles in the tung tree. Sequence and structural analyses indicated that VF16136 and VF16135 in the tung tree could be classified as belonging to Class II and I, respectively. Phylogenetic and Ka/Ks analyses revealed that Hevea brasiliensis exhibited a significantly expanded number of PR-4 genes. Additionally, the analysis of promoter cis-elements suggested that two VfPR-4 genes may play a role in the response to hormones and biotic and abiotic stress of tung trees. Furthermore, the expression patterns of VfPR-4 genes and their responses to 6-BA, salicylic acid, and silver nitrate in inflorescence buds of tung trees were evaluated using qRT-PCR. Notably, the expression of two VfPR-4 genes was found to be particularly high in leaves and early stages of tung seeds. These results suggest that VF16136 and VF16135 may have significant roles in the development of leaves and seeds in tung trees. Furthermore, these genes were found to be responsive to 6-BA, salicylic acid, and silver nitrate in the development of inflorescence buds. This research provides valuable insights for future investigation into the functions of PR-4 genes in tung trees. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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Sequence classification analysis of PR-4 protein in seven species. Different classes are marked in different colors The arrows marked six conserved cysteine residues in the PR-4 gene family. Full article ">Figure 2
Phylogenetic relationship of PR-4 in seven species. (a) Phylogenetic relationship tree. Different bootstrap values represented the credibility of the branch. Black dot: Arabidopsis thaliana; grey dot: Hevea brasiliensis; red dot: Vernicia fordii; orange dot: Ricinus communis; pink dot: Manihot esculenta; green dot: Populus trichocarpa; blue dot: Jatropha curcas. (b) Four main categories of membership statistics. Different colors pie chart indicated different classes. Orange, green, purple, and yellow pie charts represented Class Ia, Class Ib, Class Iia, and Class IIb, respectively. (c) Statistics PR-4 classifications in different species. Full article ">Figure 3
Conserved motifs and gene structures of PR-4 gene family. (a) PR-4 motif locations; 5 motifs were identified in the 30 protein sequences of PR-4 family, each motif was shown as a box in one of 5 different colors (b) PR-4 gene structures. Green boxes and black lines represented exons and introns. Full article ">Figure 4
Analyses of paralogous and orthologous PR-4 genes and Ka, Ks, and Ka/Ks. (a–d) Analyses of paralogous and orthologous PR-4 genes, circles of different colors represented different species. (e–g) Correlative relation analyses of Ka, Ks, and Ka/Ks. (Ka/Ks) > 1 was indicated positive selection, Ka/Ks = 1 was indicated neutral selection, and Ka/Ks < 1 was indicated purifying selection. Full article ">Figure 5
The cis-acting element analysis of PR-4 family genes. (a) The different cis-acting element location analysis. (b) The different colored histograms represented the sum of the cis-acting elements in each category. (c–e) Pie charts of different sizes indicated the ratio of each promoter element in each category, respectively. Full article ">Figure 6
Expression pattern of PR-4 genes in tung tree. (a–d) The relative expression of genes in different tissues and different stages of tung seeds. (e–h) The relative expression of genes in different times and different developmental stages after 6-BA treatment of inflorescence buds. (i,j) The relative expression of genes in inflorescence buds treated with SA at different concentrations. (k,l) The relative expression of genes in inflorescence buds treated with SN at different developmental stages of inflorescence buds. The data were representative of three independent biological replicates, and all data points indicated the mean ± standard error (SE) of the three biological repeats. Significant difference: *, p < 0.05; **, p < 0.01. (m) Subcellular localization analysis of VF16136 in tobacco leaves. The green light represented the GFP carried by VF16136, the red light represented the chloroplast autofluorescence, and the merge represented the co-localization of GFP and chloroplast autofluorescence in bright. (n) Subcellular localization analysis of VF16135 in tobacco leaves. The green light represented the GFP carried by VF16135, the 4′,6-diamidino-2-phenylindole (DAPI) was used as the nuclear dye. The length of the scale bar is 10 μm. Full article ">

19 pages, 17631 KiB

Open AccessArticle

Genome-Wide Identification and Characterization of the PP2C Family from Zea mays and Its Role in Long-Distance Signaling

by Huan Wu, Ling Zhu, Guiping Cai, Chenxi Lv, Huan Yang, Xiaoli Ren, Bo Hu, Xuemei Zhou, Tingting Jiang, Yong Xiang, Rujun Wei, Lujiang Li, Hailan Liu, Imran Muhammad, Chao Xia and Hai Lan

Plants 2023, 12(17), 3153; https://doi.org/10.3390/plants12173153 - 1 Sep 2023

Cited by 3 | Viewed by 1875

Abstract

The protein phosphatase 2C (PP2C) constitutes a large gene family that plays crucial roles in regulating stress responses and plant development. A recent study has shown the involvement of an AtPP2C family member in long-distance nitrogen signaling in Arabidopsis. However, it remains unclear [...] Read more.

The protein phosphatase 2C (PP2C) constitutes a large gene family that plays crucial roles in regulating stress responses and plant development. A recent study has shown the involvement of an AtPP2C family member in long-distance nitrogen signaling in Arabidopsis. However, it remains unclear whether maize adopts a similar mechanism. In this study, we conducted a genome-wide survey and expression analysis of the PP2C family in maize. We identified 103 ZmPP2C genes distributed across 10 chromosomes, which were further classified into 11 subgroups based on an evolutionary tree. Notably, cis-acting element analysis revealed the presence of abundant hormone and stress-related, as well as nitrogen-related, cis-elements in the promoter regions of ZmPP2Cs. Expression analysis demonstrated the distinct expression patterns of nine genes under two nitrogen treatments. Notably, the expression of ZmPP2C54 and ZmPP2C85 in the roots was found to be regulated by long-distance signals from the shoots. These findings provide valuable insights into understanding the roles of ZmPP2Cs in long-distance nitrogen signaling in maize. Full article

(This article belongs to the Special Issue Long Distance Signaling in Plants)

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23 pages, 1020 KiB

Open AccessReview

Are Basic Substances a Key to Sustainable Pest and Disease Management in Agriculture? An Open Field Perspective

by Silvia Laura Toffolatti, Yann Davillerd, Ilaria D’Isita, Chiara Facchinelli, Giacinto Salvatore Germinara, Antonio Ippolito, Youssef Khamis, Jolanta Kowalska, Giuliana Maddalena, Patrice Marchand, Demetrio Marcianò, Kata Mihály, Annamaria Mincuzzi, Nicola Mori, Simone Piancatelli, Erzsébet Sándor and Gianfranco Romanazzi

Plants 2023, 12(17), 3152; https://doi.org/10.3390/plants12173152 - 1 Sep 2023

Cited by 6 | Viewed by 2973

Abstract

Pathogens and pests constantly challenge food security and safety worldwide. The use of plant protection products to manage them raises concerns related to human health, the environment, and economic costs. Basic substances are active, non-toxic compounds that are not predominantly used as plant [...] Read more.

Pathogens and pests constantly challenge food security and safety worldwide. The use of plant protection products to manage them raises concerns related to human health, the environment, and economic costs. Basic substances are active, non-toxic compounds that are not predominantly used as plant protection products but hold potential in crop protection. Basic substances’ attention is rising due to their safety and cost-effectiveness. However, data on their protection levels in crop protection strategies are lacking. In this review, we critically analyzed the literature concerning the field application of known and potential basic substances for managing diseases and pests, investigating their efficacy and potential integration into plant protection programs. Case studies related to grapevine, potato, and fruit protection from pre- and post-harvest diseases and pests were considered. In specific cases, basic substances and chitosan in particular, could complement or even substitute plant protection products, either chemicals or biologicals, but their efficacy varied greatly according to various factors, including the origin of the substance, the crop, the pathogen or pest, and the timing and method of application. Therefore, a careful evaluation of the field application is needed to promote the successful use of basic substances in sustainable pest management strategies in specific contexts. Full article

(This article belongs to the Special Issue Biological Control of Plant Diseases —Volume II)

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17 pages, 2968 KiB

Open AccessArticle

Blue Light Enhances Health-Promoting Sulforaphane Accumulation in Broccoli (Brassica oleracea var. italica) Sprouts through Inhibiting Salicylic Acid Synthesis

by Youyou Guo, Chunyan Gong, Beier Cao, Tiantian Di, Xinxin Xu, Jingran Dong, Keying Zhao, Kai Gao and Nana Su

Plants 2023, 12(17), 3151; https://doi.org/10.3390/plants12173151 - 1 Sep 2023

Cited by 2 | Viewed by 1684

Abstract

As a vegetable with high nutritional value, broccoli (Brassica oleracea var. italica) is rich in vitamins, antioxidants and anti-cancer compounds. Glucosinolates (GLs) are one of the important functional components widely found in cruciferous vegetables, and their hydrolysate sulforaphane (SFN) plays a [...] Read more.

As a vegetable with high nutritional value, broccoli (Brassica oleracea var. italica) is rich in vitamins, antioxidants and anti-cancer compounds. Glucosinolates (GLs) are one of the important functional components widely found in cruciferous vegetables, and their hydrolysate sulforaphane (SFN) plays a key function in the anti-cancer process. Herein, we revealed that blue light significantly induced the SFN content in broccoli sprouts, and salicylic acid (SA) was involved in this process. We investigated the molecular mechanisms of SFN accumulation with blue light treatment in broccoli sprouts and the relationship between SFN and SA. The results showed that the SFN accumulation in broccoli sprouts was significantly increased under blue light illumination, and the expression of SFN synthesis-related genes was particularly up-regulated by SA under blue light. Moreover, blue light considerably decreased the SA content compared with white light, and this decrease was more suppressed by paclobutrazol (Pac, an inhibitor of SA synthesis). In addition, the transcript level of SFN synthesis-related genes and the activity of myrosinase (MYR) paralleled the trend of SFN accumulation under blue light treatment. Overall, we concluded that SA participates in the SFN accumulation in broccoli sprouts under blue light. Full article

(This article belongs to the Special Issue Edible Plant Sprouts: Safety in Production and Quality Control)

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16 pages, 1879 KiB

Open AccessArticle

Determination of Heavy Metal Content: Arsenic, Cadmium, Mercury, and Lead in Cyano-Phycocyanin Isolated from the Cyanobacterial Biomass

by Daiva Galinytė, Gabrielė Balčiūnaitė-Murzienė, Jūratė Karosienė, Dmitrij Morudov, Rima Naginienė, Dalė Baranauskienė, Jurgita Šulinskienė, Ieva Kudlinskienė, Arūnas Savickas and Nijolė Savickienė

Plants 2023, 12(17), 3150; https://doi.org/10.3390/plants12173150 - 1 Sep 2023

Cited by 3 | Viewed by 2594

Abstract

Cyano-phycocyanin (C-PC) is a light-absorbing biliprotein found in cyanobacteria, commonly known as blue-green algae. Due to its antioxidative, anti-inflammatory, and anticancer properties, this protein is a promising substance in medicine and pharmaceuticals. However, cyanobacteria tend to bind heavy metals from the environment, making [...] Read more.

Cyano-phycocyanin (C-PC) is a light-absorbing biliprotein found in cyanobacteria, commonly known as blue-green algae. Due to its antioxidative, anti-inflammatory, and anticancer properties, this protein is a promising substance in medicine and pharmaceuticals. However, cyanobacteria tend to bind heavy metals from the environment, making it necessary to ensure the safety of C-PC for the development of pharmaceutical products, with C-PC isolated from naturally collected cyanobacterial biomass. This study aimed to determine the content of the most toxic heavy metals, arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in C-PC isolated from different cyanobacterial biomasses collected in the Kaunas Lagoon during 2019–2022, and compare them with the content of heavy metals in C-PC isolated from cultivated Spirulina platensis (S. platensis). Cyanobacteria of Aphanizomenon flos-aquae (A. flos-aquae) dominated the biomass collected in 2019, while the genus Microcystis dominated the biomasses collected in the years 2020 and 2022. Heavy metals were determined using inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS analysis revealed higher levels of the most investigated heavy metals (Pb, Cd, and As) in C-PC isolated from the biomass with the dominant Microcystis spp. compared to C-PC isolated from the biomass with the predominant A. flos-aquae. Meanwhile, C-PC isolated from cultivated S. platensis exhibited lower concentrations of As and Pb than C-PC isolated from naturally collected cyanobacterial biomass. Full article

(This article belongs to the Special Issue Phytochemical Profiles of Plant Materials: From Extracts to Added Value Ingredients)

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Content of heavy metals in C-PC samples (μg/g dw). (a) Heavy metal concentrations in sample S1. (b) Heavy metal concentrations in sample S2. (c) Heavy metal concentrations in sample S3. (d) Heavy metal concentrations in sample S4. Different letters above the bars indicate significant differences among the different metal concentrations (p < 0.05) identified using Dunnett’s T3 test. Means and standard deviations are presented. The experiment was repeated 4 times. Full article ">Figure 2
The purity coefficients of C-PC samples S1, S2, S3, and S4. Different letters above the bars indicate significant differences (p < 0.05) identified using Bonferroni’s test. Means and standard deviations are presented. The experiment was repeated 3 times. Full article ">Figure 3
Graphical representation of heavy metal concentrations (μg/g dw) in C-PC samples. (a) Pb concentration. (b) Cd concentration. (c) As concentration. (d) Hg concentration. Different letters above the bars indicate significant differences among the different metals (p < 0.05) identified using Bonferroni’s test. Means and standard deviations are presented. The experiment was repeated 4 times. Full article ">Figure 4
Heavy metal content (μg/L) in the surface water and bottom sediments of the Kaunas Lagoon. (a) Pb and As content in the surface water of the Kaunas Lagoon. (b) Pb and As content in the bottom sediments of the Kaunas Lagoon. (c) Hg and Cd content in the surface water of the Kaunas Lagoon. (d) Hg and Cd content in the bottom sediments of the Kaunas Lagoon [<a href="#B15-plants-12-03150" class="html-bibr">15</a>]. Full article ">Figure 5
Changes in the average annual water temperature and pH of the Kaunas Lagoon in 2019–2022. Full article ">

12 pages, 4948 KiB

Open AccessArticle

Screening for Fungicide Efficacy in Controlling Blackleg Disease in Wasabi (Eutrema japonicum)

by Yanjun Liu, Changjiang Song, Xin Ren, Guoli Wu, Zihan Ma, Mantong Zhao, Yujia Xie, Yu Li and Yunsong Lai

Plants 2023, 12(17), 3149; https://doi.org/10.3390/plants12173149 - 1 Sep 2023

Viewed by 1544

Abstract

Blackleg disease is devastating for wasabi (Eutrema japonicum) production, occurring at any time and everywhere within the main production area of the Sichuan Province, China. There have been very few studies on the chemical control of this disease. In this study, [...] Read more.

Blackleg disease is devastating for wasabi (Eutrema japonicum) production, occurring at any time and everywhere within the main production area of the Sichuan Province, China. There have been very few studies on the chemical control of this disease. In this study, we isolated and identified a local popular strain of the pathogen Plenodomus wasabiae. The isolated fungus strain caused typical disease spots on the leaves and rhizomes upon inoculation back to wasabi seedlings. The symptoms of blackleg disease developed very quickly, becaming visible on the second day after exposure to P. wasabiae and leading to death within one week. We then evaluated the efficacy of ten widely used fungicides to screen out effective fungicides. The efficacy of the tested fungicides was determined through mycelial growth inhibition on medium plates. As a result, tebuconazole and pyraclostrobin were able to inhibit the mycelial growth of P. wasabiae, and the most widely used dimethomorph in local production areas produced the lowest inhibition activity (13.8%). Nevertheless, the highest control efficacy of tebuconazole and pyraclostrobin on wasabi seedlings was only 47.48% and 39.03%, respectively. Generally, the control efficacy of spraying the fungicide before inoculation was better than that after inoculation. An increase in the application concentration of the two fungicides did not proportionately result in improved performance. We cloned the full-length sequence of sterol 14-demethylase (CYP51) and cytochrome B (CYTB) of which the mutations may contribute to the possible antifungalresistance. These two genes of the isolated fungus do not possess any reported mutations that lead to fungicide resistance. Previous studies indicate that there is a significant difference between fungicides in terms of the effectiveness of controlling blackleg disease; however, the control efficacy of fungicides is limited in blackleg control. Therefore, field management to prevent wound infection and unfavorable environmental conditions are more important than pesticide management. Full article

(This article belongs to the Special Issue Advances in Plant-Fungal Pathogen Interaction)

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Identification of P. wasabiae. (A) The disease developed fast along vascular bundles. The red arrows and blue arrows indicate the infected vascular and stem epidermis. (B) Morphology of the fungus plaque on a PDA medium and the electrophoresis of ITS sequence. (C) Phylogenetic analysis of internal transcribed spacer (ITS) sequences between 18S rRNA and 25S rRNA. P1 in the red box indicates the isolated pathogen in this study. (D) The isolated fungus caused blackleg disease when inoculated back to leaves and rhizomes. Full article ">Figure 2
Symptom development of blackleg disease after artificial inoculation. (A) Symptoms on the leaves. (B) Symptoms on the petioles. (C) Symptoms on the rhizomes. The black disease spot was noted by the yellow circle. (D) The severity of blackleg disease was quantified according to the proportion of disease spots. The proportion of the area covered by disease spots on the leaves. The proportion of the length covered by disease spots on the petioles and rhizomes. The symptoms were investigated every day from 1 day post-inoculation (dpi) to 6 dpi. Full article ">Figure 3
Inhibition activity of the tested fungicides on P. wasabiae growth. (A) Tebuconazole. (B) Pyraclostrobin. (C) Dimethomorph. (D) CK: 9.50 mL PDA medium + 0.50 mL sterile water. Full article ">Figure 4
The comparison of PwCYP51 and PwCYTB with homologous genes that possess antifungal resistance mutations. (A) CYP51. Leptosphaeria maculans (Genbank: CBX97082), Plenodomus tracheiphilus (Genbank: KAF2854801), Cryptococcus neofomans var. beoformans (Genbank: AF225914) and Candidaalbicans (Genbank: AF153850). (B) CYTB. Didymella pinodes (Genbank: YP009233081), Phoma sp. (Genbank: UXC95304), Pseudoperonospora cubensis (Genbank: AHC28174) and Cercospora beticola (Genbank: AFN43048). Full article ">

15 pages, 2514 KiB

Open AccessArticle

Humic Substances Isolated from Recycled Biomass Trigger Jasmonic Acid Biosynthesis and Signalling

by Rakiely M. Silva, Alice N. A. Peres, Lázaro E. P. Peres, Fábio L. Olivares, Sara Sangi, Natália A. Canellas, Riccardo Spaccini, Silvana Cangemi and Luciano P. Canellas

Plants 2023, 12(17), 3148; https://doi.org/10.3390/plants12173148 - 1 Sep 2023

Cited by 4 | Viewed by 1429

Abstract

Intensive agriculture maintains high crop yields through chemical inputs, which are well known for their adverse effects on environmental quality and human health. Innovative technologies are required to reduce the risk generated by the extensive and harmful use of pesticides. The plant biostimulants [...] Read more.

Intensive agriculture maintains high crop yields through chemical inputs, which are well known for their adverse effects on environmental quality and human health. Innovative technologies are required to reduce the risk generated by the extensive and harmful use of pesticides. The plant biostimulants made from humic substances isolated from recyclable biomass offer an alternative approach to address the need for replacing conventional agrochemicals without compromising the crop yield. The stimulatory effects of humic substances are commonly associated with plant hormones, particularly auxins. However, jasmonic acid (JA) is crucial metabolite in mediating the defence responses and governing plant growth and development. This work aimed to evaluate the changes in the biosynthesis and signalling pathway of JA in tomato seedlings treated with humic acids (HA) isolated from vermicompost. We use the tomato model system cultivar Micro-Tom (MT) harbouring a reporter gene fused to a synthetic promoter that responds to jasmonic acid (JERE::GUS). The transcript levels of genes involved in JA generation and activity were also determined using qRT-PCR. The application of HA promoted plant growth and altered the JA status, as revealed by both GUS and qRT-PCR assays. Both JA enzymatic synthesis (LOX, OPR3) and JA signalling genes (JAZ and JAR) were found in higher transcription levels in plants treated with HA. In addition, ethylene (ETR4) and auxin (ARF6) signalling components were positively modulated by HA, revealing a hormonal cross-talk. Our results prove that the plant defence system linked to JA can be emulated by HA application without growth inhibition. Full article

(This article belongs to the Special Issue Plant Growth Promoters: The Eliciting Role of Recycled Biomasses)

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Spectrum of IR-TF (a) and CP/MAS 13C NMR (b) of humic acids isolated from vermicompost. Full article ">Figure 2
(A) Phenotypes of 30-day-old MT tomatoes seedlings exposed to water as a control, 1 mM MeJA, 4 and 8 mM C HA (humic acids). Fresh weight of roots (B) and shoots (C) treated with 1 mM MeJA, 4 and 8 mM C HA. Data represent the mean and bars standard deviation (n = 10). Means followed by different letters are significantly different by the LSD test (p < 0.05). Full article ">Figure 3
Leaves of Micro-Tom (MT) with gene reporter JERE: GUS were used to perform the GUS staining assays: (A) control, (B) 1 mM MeJ, (C) HA 4 mM C L−1, (D) HA 8 mM C L−1, (E) HA 16 mM C L−1, (F) HA 32 mM C L−1. Full article ">Figure 4
Gene expression linked to jasmonate biosynthesis. phospholipase1 (PLDa1), lipoxygenase (LOX2), alene oxide cyclase (AOC), 12-oxo-phytodienoic acid (OPDA) reductase3 (OPR3) genes in MT tomatoes treated with 1 mM of methyl jasmonate (MeJA) and 4 and 8 mM C of humic acids (HA) isolated from vermicompost. Total RNA was extracted from leaves and subjected to real-time qPCR analysis. Data represent the mean of three independent samples with SD. * significant difference at p < 0.05 by t test. The data are expressed concerning control treatment considered = 0. Full article ">Figure 5
Gene expression linked to jasmonate signalling. bHLH transcription Factor (MYC2) jasmonate zim domain (JAZ) and jasmonic acid-amino acid synthetase (JAR) in tomato MT exogenous treated with 1 mM methyl jasmonate (MeJA) and 4 and 8 mM C of humic acids (HA) isolated from vermicompost. Total RNA was extracted from leaves and subjected to real-time qPCR analysis. Data represent the mean of three independent samples with SD. * significant difference at p < 0.05 by t test. The data are expressed concerning control treatment considered = 0. Full article ">Figure 6
Gene expression linked to herbivory (cellulose synthase-CEVI57), ethylene-jasmonate cross-talk (ethylene response sensor-ETR4) and jasmonate-auxin cross-talk (auxins response factors, ARF6 and ARF8) in tomato MT exogenous treated with 1 mM methyl jasmonate (MeJA) and 4 and 8 mM C of humic acids (HA) isolated from vermicompost. Total RNA was extracted from leaves and subjected to real-time qPCR analysis. Data represent the mean of three independent samples with SD. * significant difference at p < 0.05 by t test. The data are expressed concerning control treatment considered = 0. Full article ">Figure 7
Effect of methyl jasmonate (MeJA) and 4 and 8 mM C of humic acids (HA) isolated from vermicompost on glandular trichome density on MT tomato leaves. (A) mean density of type VI glandular trichome on the adaxial (upper) leaf surface and (B) abaxial (lower) l leaf surface. N = 10 plants per treatment, one leaf examined per plant. Densities are calculated from counts of trichomes on two leaf disks per leaf. Data represent the mean and bar standard deviation. Means followed by different letters are significantly different from the LSD test (p < 0.05). Full article ">

38 pages, 2471 KiB

Open AccessReview

Recent Advances in Microbial-Assisted Remediation of Cadmium-Contaminated Soil

by Usman Zulfiqar, Fasih Ullah Haider, Muhammad Faisal Maqsood, Waqas Mohy-Ud-Din, Muhammad Shabaan, Muhammad Ahmad, Muhammad Kaleem, Muhammad Ishfaq, Zoya Aslam and Babar Shahzad

Plants 2023, 12(17), 3147; https://doi.org/10.3390/plants12173147 - 31 Aug 2023

Cited by 56 | Viewed by 6758

Abstract

Soil contamination with cadmium (Cd) is a severe concern for the developing world due to its non-biodegradability and significant potential to damage the ecosystem and associated services. Industries such as mining, manufacturing, building, etc., rapidly produce a substantial amount of Cd, posing environmental [...] Read more.

Soil contamination with cadmium (Cd) is a severe concern for the developing world due to its non-biodegradability and significant potential to damage the ecosystem and associated services. Industries such as mining, manufacturing, building, etc., rapidly produce a substantial amount of Cd, posing environmental risks. Cd toxicity in crop plants decreases nutrient and water uptake and translocation, increases oxidative damage, interferes with plant metabolism and inhibits plant morphology and physiology. However, various conventional physicochemical approaches are available to remove Cd from the soil, including chemical reduction, immobilization, stabilization and electro-remediation. Nevertheless, these processes are costly and unfriendly to the environment because they require much energy, skilled labor and hazardous chemicals. In contrasting, contaminated soils can be restored by using bioremediation techniques, which use plants alone and in association with different beneficial microbes as cutting-edge approaches. This review covers the bioremediation of soils contaminated with Cd in various new ways. The bioremediation capability of bacteria and fungi alone and in combination with plants are studied and analyzed. Microbes, including bacteria, fungi and algae, are reported to have a high tolerance for metals, having a 98% bioremediation capability. The internal structure of microorganisms, their cell surface characteristics and the surrounding environmental circumstances are all discussed concerning how microbes detoxify metals. Moreover, issues affecting the effectiveness of bioremediation are explored, along with potential difficulties, solutions and prospects. Full article

(This article belongs to the Special Issue Steps Forward in Phytoremediation Technologies: Overcoming the Challenges)

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16 pages, 1073 KiB

Open AccessReview

Environmental Factors Affecting Monoterpene Emissions from Terrestrial Vegetation

by Tanzil Gaffar Malik, Lokesh Kumar Sahu, Mansi Gupta, Bilal Ahmad Mir, Triratnesh Gajbhiye, Rashmi Dubey, Andrea Clavijo McCormick and Sudhir Kumar Pandey

Plants 2023, 12(17), 3146; https://doi.org/10.3390/plants12173146 - 31 Aug 2023

Cited by 8 | Viewed by 3084

Abstract

Monoterpenes are volatile organic compounds that play important roles in atmospheric chemistry, plant physiology, communication, and defense. This review compiles the monoterpene emission flux data reported for different regions and plant species and highlights the role of abiotic environmental factors in controlling the [...] Read more.

Monoterpenes are volatile organic compounds that play important roles in atmospheric chemistry, plant physiology, communication, and defense. This review compiles the monoterpene emission flux data reported for different regions and plant species and highlights the role of abiotic environmental factors in controlling the emissions of biogenic monoterpenes and their emission fluxes for terrestrial plant species (including seasonal variations). Previous studies have demonstrated the role and importance of ambient air temperature and light in controlling monoterpene emissions, likely contributing to higher monoterpene emissions during the summer season in temperate regions. In addition to light and temperature dependence, other important environmental variables such as carbon dioxide (CO₂), ozone (O₃), soil moisture, and nutrient availability are also known to influence monoterpene emissions rates, but the information available is still limited. Throughout the paper, we identify knowledge gaps and provide recommendations for future studies. Full article

(This article belongs to the Topic Plants Volatile Compounds)

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16 pages, 3856 KiB

Open AccessArticle

Effect of the Nonpathogenic Strain Fusarium oxysporum FO12 on Fe Acquisition in Rice (Oryza sativa L.) Plants

by Jorge Núñez-Cano, Francisco J. Romera, Pilar Prieto, María J. García, Jesús Sevillano-Caño, Carlos Agustí-Brisach, Rafael Pérez-Vicente, José Ramos and Carlos Lucena

Plants 2023, 12(17), 3145; https://doi.org/10.3390/plants12173145 - 31 Aug 2023

Cited by 3 | Viewed by 1325

Abstract

Rice (Oryza sativa L.) is a very important cereal worldwide, since it is the staple food for more than half of the world’s population. Iron (Fe) deficiency is among the most important agronomical concerns in calcareous soils where rice plants may suffer [...] Read more.

Rice (Oryza sativa L.) is a very important cereal worldwide, since it is the staple food for more than half of the world’s population. Iron (Fe) deficiency is among the most important agronomical concerns in calcareous soils where rice plants may suffer from this deficiency. Current production systems are based on the use of high-yielding varieties and the application of large quantities of agrochemicals, which can cause major environmental problems. The use of beneficial rhizosphere microorganisms is considered a relevant sustainable alternative to synthetic fertilizers. The main goal of this study was to determine the ability of the nonpathogenic strain Fusarium oxysporum FO12 to induce Fe-deficiency responses in rice plants and its effects on plant growth and Fe chlorosis. Experiments were carried out under hydroponic system conditions. Our results show that the root inoculation of rice plants with FO12 promotes the production of phytosiderophores and plant growth while reducing Fe chlorosis symptoms after several days of cultivation. Moreover, Fe-related genes are upregulated by FO12 at certain times in inoculated plants regardless of Fe conditions. This microorganism also colonizes root cortical tissues. In conclusion, FO12 enhances Fe-deficiency responses in rice plants, achieves growth promotion, and reduces Fe chlorosis symptoms. Full article

(This article belongs to the Special Issue Biochemical Interactions of Iron Nutrition in Plants)

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Figure 1
Effect of the inoculation with the nonpathogenic strain Fusarium oxysporum FO12 on the SPAD index of rice plants grown under Fe sufficiency or Fe deficiency. SPAD index determinations were carried out at 3, 6, 9 and 12 d after treatments. Treatments: –Fe, –Fe+FO12, +Fe and +Fe+FO12. The values represented are mean ± ES (n = 8). Within each time, ** p < 0.01 or *** p < 0.001 indicate significant differences between treatments. For each evaluation moment, different lowercase or capital letters indicate significant differences between non-inoculated or inoculated plants with FO12 for +Fe or –Fe treatments, respectively. Full article ">Figure 2
Effect of Fe deficiency and inoculation with FO12 in the growth of rice plants. (a) Shoot fresh weight. (b) Root fresh weight. To determine this effect, half of the 22 d old plants were inoculated. Then, both inoculated and control plants were cultivated for 12 additional days, either under Fe sufficiency (+Fe) or Fe deficiency (–Fe). After that time, roots and shoots were excised and weighed separately. The values represented are mean ± ES (n = 8). Different letters indicate significant differences according to Duncan’s multiple range test (p < 0.05). Similarly, *** p < 0.001 indicate significant differences between treatments. Full article ">Figure 3
Evolution of phytosiderophore production in rice plants during 48 h of treatments. Four treatments were carried out: plants with Fe (+Fe), plants with Fe and inoculated with FO12 (+Fe+FO12), plants without Fe (–Fe), plants without Fe and inoculated with FO12 (–Fe+FO12). The inoculation was carried out the same day the Fe-deficiency treatment was applied. Within each sampling time, * or ** indicate significant differences (p < 0.05 or p < 0.01) relative to their respective non-inoculated control plants. Full article ">Figure 4
Effect of FO12 on the relative expression of PS-related genes (TOM1, IRO2, IRT1, NAAT and YSL15) in roots of rice plants. Four treatments were carried out: plants with Fe (+Fe), plants with Fe and inoculated with FO12 (–Fe+FO12), plants without Fe (–Fe), and plants without Fe and inoculated with FO12 (+Fe+FO12). The data represent the mean ± SE of three independent biological replicates and two technical replicates 2 d after treatments. Within each time, * p < 0.05 or *** p < 0.001 indicate significant differences in relation to the control treatment. Full article ">Figure 5
CLSM images of the time-course colonization processes of rice roots by the GFP-FO12 (in green). Confocal analysis was carried out on 4–5 cm long roots to show surface GFP-FO12 colonization. Images are projections of 20 adjacent confocal optical sections. The focal step between confocal optical sections was 0.5 μm. (a,b) Surface colonization at 4 dai by GFP-FO12 on rice roots of plants (a) without Fe, and with a supplement of (b) 70 μM Fe. (c,d) Surface colonization at 10 dai by GFP-FO12 on rice roots of plants growing (c) without Fe and (d) with an addition of 70 μM Fe. (e,f) Surface and internal (inset) colonization at 15 dai by GFP-FO12 on rice roots of plants (e) without Fe and (f) with a supplement of 70 μM Fe. (g,h) Surface colonization at 18 dai by GFP-FO12 on rice roots of plants (g) without Fe and (h) with a supplement of 70 μM Fe. (i,j) Surface colonization at 21 dai by GFP-FO12 on rice roots of plants (i) without Fe and (j) with a supplement of 70 μM Fe. Rice roots were colonized by GFP-FO12 hyphae in plants growing both in the presence and in the absence of Fe during the whole bioassay. Full article ">

18 pages, 2770 KiB

Open AccessArticle

Global Transcriptome and Co-Expression Network Analyses Revealed Hub Genes Controlling Seed Size/Weight and/or Oil Content in Peanut

by Lingli Yang, Li Yang, Yingbin Ding, Yuning Chen, Nian Liu, Xiaojing Zhou, Li Huang, Huaiyong Luo, Meili Xie, Boshou Liao and Huifang Jiang

Plants 2023, 12(17), 3144; https://doi.org/10.3390/plants12173144 - 31 Aug 2023

Cited by 3 | Viewed by 1465

Abstract

Cultivated peanut (Arachis hypogaea L.) is an important economic and oilseed crop worldwide, providing high-quality edible oil and high protein content. Seed size/weight and oil content are two important determinants of yield and quality in peanut breeding. To identify key regulators controlling [...] Read more.

Cultivated peanut (Arachis hypogaea L.) is an important economic and oilseed crop worldwide, providing high-quality edible oil and high protein content. Seed size/weight and oil content are two important determinants of yield and quality in peanut breeding. To identify key regulators controlling these two traits, two peanut cultivars with contrasting phenotypes were compared to each other, one having a larger seed size and higher oil content (Zhonghua16, ZH16 for short), while the second cultivar had smaller-sized seeds and lower oil content (Zhonghua6, ZH6). Whole transcriptome analyses were performed on these two cultivars at four stages of seed development. The results showed that ~40% of the expressed genes were stage-specific in each cultivar during seed development, especially at the early stage of development. In addition, we identified a total of 5356 differentially expressed genes (DEGs) between ZH16 and ZH6 across four development stages. Weighted gene co-expression network analysis (WGCNA) based on DEGs revealed multiple hub genes with potential roles in seed size/weight and/or oil content. These hub genes were mainly involved in transcription factors (TFs), phytohormones, the ubiquitin–proteasome pathway, and fatty acid synthesis. Overall, the candidate genes and co-expression networks detected in this study could be a valuable resource for genetic breeding to improve seed yield and quality traits in peanut. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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Phenotype differences between ZH16 and ZH6 at four stages of seed development. (A) Graphical display of seeds at different stages of development (S1–S4) between ZH16 and ZH6. (B) Average 100-seed weights (g) between ZH16 and ZH6. (C) Average oil content between ZH16 and ZH6. ***, p < 0.001; ****, p < 0.0001 (Student’s t-tests). Full article ">Figure 2
Global gene expression profiles in ZH16 and ZH6. (A) PCA plot showing clustering of gene transcript levels at four stages of seed development in ZH16 and ZH6. (B) Proportion of genes with different expression levels (based on FPKM). (C,D) Venn diagrams of expressed genes amongfour stages of seed development in cultivars ZH16 (C) and ZH6 (D). Full article ">Figure 3
Genes with stage-specific expression during seed development in peanut cultivars ZH16 and ZH6. (A) Bar graph showing numbers of stage-specific expressed genes specifically or commonly present in ZH16 and/or ZH6 at each stage of seed development. (B) Heatmap showing the expression of common stage-specific expressed genes at different stages in ZH16 and ZH6. Color scale represents Z-score. (C,D) Enriched functional GO terms (biological process) of common stage-specific expressed genes in two cultivars at the S1 (C) and S2 (D) stages. Full article ">Figure 4
DEGs between ZH16 and ZH6 at different seed developmental stages. (A) Number of up-regulated and down-regulated genes. (B) Distribution of Log2FC values of DEGs. (C,D) Venn diagrams showing numbers of DEGs concurrently or specifically expressed among four stages. (E) Enriched GO terms (biological process) of up- and down-regulated genes. The color scale represents significance (corrected p-value). Full article ">Figure 5
WGCNA of DEGs between ZH16 and ZH6 at each seed developmental stage. (A) Module–sample relationships. The number of genes within key modules is indicated next to the module name. Color bars represent negative (blue) and positive (red) correlations. (B–D) Expression patterns of DEGs in magenta (B), yellow (C), and red (D) modules. Full article ">Figure 6
Heatmap and co-expression networks of DEGs within three key modules. (A,C,E) Heatmaps of hub genes. Genes overlapping with reported QTLs are marked in red. (B,D,F) Co-expression networks. Purple, blue, orange, and red nodes represent hub genes involved in TFs, phytohormones, the ubiquitin–proteasome pathway, and fatty acid synthesis, respectively. Node size represents connectivity. Full article ">

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Plants, Volume 12, Issue 17 (September-1 2023) – 157 articles

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