Search Results (3,083)

Abiotic factors, such as drought, can significantly impact the vegetative growth and productivity of maize. To investigate the effects of the combined foliar application of zinc (Zn) and iron (Fe) nanoparticles with the recommended nitrogen dose (RND) on maize production and grain chemical composition under different water regimes, two field experiments were conducted in El-Ayyat city, Giza, Egypt, during the summer seasons of 2022 and 2023. This study utilized a split-split-plot experimental design with three replications. The main plots were designated to different water regimes (100, 80, 60, and 40% of estimated evapotranspiration), while the sub-plots were randomly distributed with Zn and Fe nanoparticle concentrations (0, 100, and 200 mg/L). The sub-sub-plots were randomly allocated to three maize cultivars (SC-P3062, SC-32D99, and SC-P3433). The results revealed that exposure to drought conditions resulted in a significant decline in the yield and yield-related attributes across all maize cultivars examined. Grain yield decreased by 10–50% under drought conditions. However, the foliar application of Zn and Fe nanoparticles was found to significantly improve grain yield, protein content, oil content, starch content, crude fiber, ash, and macro- and micronutrient concentrations in the maize cultivars under control and drought stress conditions. The foliar application of Zn and Fe nanoparticles at a concentration of 200 mg/L to the SC-P3433 maize cultivar led to the greatest grain yield per hectare, reaching 11,749 and 11,657 kg under the irrigation regimes with 100 and 80% total evapotranspiration, respectively. According to the assessment using the relative drought index, the SC-P3062 maize cultivar demonstrated tolerance (T) to water stress conditions. In conclusion, the foliar application of Zn and Fe nanoparticles (100–200 mg/L) effectively mitigated the negative effects of drought stress on maize plants. This approach can be recommended for farmers in arid and semi-arid regions to maintain and improve maize yield and grain quality under water-deficit conditions. Full article

Sweet sorghum (Sorghum bicolor L. Moench) has significant cultivation potential in arid and saline–alkaline regions due to its drought and salt tolerance. This study aims to evaluate the mechanisms by which increased soil salinity and reduced irrigation affect the growth, aboveground biomass, and stem sugar content of sweet sorghum. A two-year field experiment was conducted, with four salinity levels (CK: 4.17 dS/m, S1: 5.83 dS/m, S2: 7.50 dS/m, and S3: 9.17 dS/m) and three irrigation levels (W1: 90 mm, W2: 70 mm, and W3: 50 mm). The results showed that increased salinity and reduced irrigation significantly reduced both the emergence rate and aboveground biomass, with the decreases in the emergence rate ranging from 11.0% to 36.2% and the reductions in the aboveground biomass ranging from 15.9% to 43.8%. Additionally, increased soil salinity led to reductions in stem sugar content of 6.3% (S1), 8.8% (S2), and 12.8% (S3), respectively. The results also indicated that photosynthetic efficiency, including the net photosynthetic rate (Pn), stomatal conductance (Gs), and chlorophyll content (SPAD), was significantly hindered under increased water and salt stress, with the Pn decreasing by up to 50.4% and the SPAD values decreasing by up to 36.3% under the highest stress conditions. These findings underscore the adverse impacts of increased soil salinity and reduced irrigation on sweet sorghum’s growth, photosynthetic performance, and sugar accumulation, offering critical insights for optimizing its cultivation in arid and saline environments. Full article

Blueberry plants are among the most important fruit-bearing shrubs, but they have shallow, hairless roots that are not conducive to water and nutrient uptake, especially under drought conditions. Therefore, the mechanism underlying blueberry root drought tolerance should be clarified. Hence, we established a yeast expression library comprising blueberry genes associated with root responses to drought stress. High-throughput sequencing technology enabled the identification of 1475 genes potentially related to drought tolerance. A subsequent KEGG enrichment analysis revealed 77 key genes associated with six pathways: carbon and energy metabolism, biosynthesis of secondary metabolites, nucleotide and amino acid metabolism, genetic information processing, signal transduction, and material transport and catabolism. Metabolomic profiling of drought-tolerant yeast strains under drought conditions detected 1749 differentially abundant metabolites (DAMs), including several up-regulated metabolites (organic acids, amino acids and derivatives, alkaloids, and phenylpropanoids). An integrative analysis indicated that genes encoding several enzymes, including GALM, PK, PGLS, and PIP5K, modulate key carbon metabolism-related metabolites, including D-glucose 6-phosphate and β-D-fructose 6-phosphate. Additionally, genes encoding FDPS and CCR were implicated in terpenoid and phenylalanine biosynthesis, which affected metabolite contents (e.g., farnesylcysteine and tyrosine). Furthermore, genes for GST and GLT1, along with eight DAMs, including L-γ-glutamylcysteine and L-ornithine, contributed to amino acid metabolism, while genes encoding NDPK and APRT were linked to purine metabolism, thereby affecting certain metabolites (e.g., inosine and 3′,5′-cyclic GMP). Overall, the yeast functional screening system used in this study effectively identified genes and metabolites influencing blueberry root drought tolerance, offering new insights into the associated molecular mechanisms. Full article

Heterotrimeric G-proteins are fundamental signal transducers highly conserved in plant species, which play crucial roles in regulating plant growth, development, and responses to abiotic stresses. Identification of G-protein members and their expression patterns in plants are essential for improving crop resilience against environmental stresses. Here, we identified eight heterotrimeric G-protein genes localized on four chromosomes within the barley genome by using comprehensive genome-wide analysis. Phylogenetic analysis classified these genes into four distinct subgroups with obvious evolutionary relationships. Further analysis on gene structure, protein motif, and structure indicated that G-proteins within each evolutionary branch exhibited similar exon-intron organization, conserved motif patterns, and structural features. Collinearity analysis showed no significant collinear relationships among those G-protein genes, indicating a unique evolutionary trajectory within barley. Moreover, cis-regulatory elements detected in the upstream sequences of these genes were involved in response to plant hormones and signaling molecules. Expression analyses revealed tissue-specific expression patterns and differential regulation in response to abiotic stresses. The expression patterns of G-protein genes were further validated using a quantitative real-time PCR (qRT-PCR) technique, indicating the reliability of transcriptomic data, as well as special responses to salt, drought, and waterlogging stresses. These findings may provide underlying mechanisms by which G-protein genes participate in salt tolerance of barley, and also highlight candidate genes for potential genetic engineering applications in improving crop resilience to salinity stress. Full article

β-ketoacyl-CoA synthase (KCS) enzymes play a pivotal role in plants by catalyzing the first step of very long-chain fatty acid (VLCFA) biosynthesis. This process is crucial for plant development and stress responses. However, the understanding of KCS genes in maize remains limited. In this study, we present a comprehensive analysis of ZmKCS genes, identifying 29 KCS genes that are unevenly distributed across nine maize chromosomes through bioinformatics approaches. These ZmKCS proteins varied in length and molecular weight, suggesting functional diversity. Phylogenetic analysis categorized 182 KCS proteins from seven species into six subgroups, with maize showing a closer evolutionary relationship to other monocots. Collinearity analysis revealed 102 gene pairs between maize and three other monocots, whereas only five gene pairs were identified between maize and three dicots, underscoring the evolutionary divergence of KCS genes between monocotyledonous and dicotyledonous plants. Structural analysis revealed that 20 out of 29 ZmKCS genes are intronless. Subcellular localization prediction and experimental validation suggest that most ZmKCS proteins are likely localized at the plasma membrane, with some also present in mitochondria and chloroplasts. Analysis of the cis-acting elements within the ZmKCS promoters suggested their potential involvement in abiotic stress responses. Notably, expression analysis under abiotic stresses highlighted ZmKCS17 as a potential key gene in the stress response of maize, which presented an over 10-fold decrease in expression under salt and drought stresses within 48 h. This study provides a fundamental understanding of ZmKCS genes, paving the way for further functional characterization and their potential application in maize breeding for enhanced stress tolerance. Full article

The root is an important organ by which plants directly sense variation in soil moisture. The discovery of drought stress-responsive genes in roots is very important for the improvement of drought tolerance in wheat varieties via molecular approaches. In this study, transcriptome sequencing was conducted on the roots of drought-tolerant wheat cultivar YH1818 seedlings at 0, 2, and 7 days after treatment (DAT). Based on a weighted gene correlation network analysis of differentially expressed genes (DEGs), 14 coexpression modules were identified, of which five modules comprising 3107 DEGs were related to 2 or 7 DAT under drought stress conditions. A total of 223,357 single-nucleotide polymorphisms (SNPs) of these DEGs were retrieved from public databases. Using the R language package and GAPIT program, association analysis was performed between the 223,357 SNPs and the drought tolerance coefficient (DTC) values of six drought resistance-related traits in 114 wheat germplasms. The results revealed that 18 high-confidence SNPs of 10 DEGs, including TaPK, TaRFP, TaMCO, TaPOD, TaC3H-ZF, TaGRP, TaDHODH, TaPPDK, TaLectin, and TaARF7-A, were associated with drought tolerance. The RT–qPCR results confirmed that these genes were significantly upregulated by drought stress at 7 DAT. Among them, TaARF7-A contained three DTC-related SNPs, which presented two haplotypes in the tested wheat germplasms. YH1818 belongs to the Hap1 allele, which is involved in increased drought tolerance. This study revealed key modules and candidate genes for understanding the drought-stress response mechanism in wheat roots. Full article

Pineapple (Ananas comosus (L.) Merr.) is an economically significant and delicious tropical fruit. Pineapple commercial production faces severe decline due to abiotic stresses, which affect the development and quality of pineapple fruit. Heat shock protein 70 (HSP70) plays an essential role in abiotic stress tolerance. However, the pineapple HSP70 family identification and expression analysis in response to abiotic stresses has not been studied. To explore the functional role of AcHSP70, different abiotic stress treatments were applied to pineapple cultivar “Bali” seedlings. A total of 21 AcHSP70 members were identified in the pineapple genome. The identified genes were classified into four subfamilies (I–IV) using phylogenetic analysis. The AcHSP70 family is expressed under different stress conditions. Quantitative real time polymerase chain reaction (qRT-PCR) revealed the expression pattern of the AcHSP70 family under cold, drought, salt, and heat stress. The expression level of genes such as AcHSP70-2 increased under heat, cold, and drought stress, while the expression level of genes such as AcHSP70-3 decreased under salt stress. Furthermore, the expression profile of AcHSP70s in different tissues and development stages was analyzed using transcriptome analysis. The HSP70 genes exhibited unique expression patterns in pineapple tissue at different developmental stages. The study therefore provides a list of HSP70 genes with substantial roles in abiotic stress response and valuable information for understanding AcHSP70 functional characteristics during abiotic stress tolerance in pineapple. Full article

To supply information concerning the application of poly-glutamic acid (PGA) in the drought-resistant cultivation of red sage (Salvia miltiorrhiza), we investigated the role of PGA in regulating the physiological characteristics, plant growth, and the accumulation of the main medical components in the root under water shortage. The findings showed that different levels of water shortage (WS) all suppressed the photosynthetic function by reducing the net photosynthetic rate (Pn), Soil and plant analyzer development (SPAD) value, maximum photochemical efficiency of PSII (F_v/F_m), photochemical quenching (q_P), and actual photochemical efficiency of PSII (Y(II)), as well as increasing non-photochemical quenching (q_N). Compared with WS, PGA plus WS enhanced the photosynthetic function by reducing q_N and increasing the other indicators above. For water metabolism, WS increased stomatal limit value (Ls) and water use efficiency (WUE), but decreased transpiration rate (Tr) and stomatal conductance (Gs). Compared with WS, PGA plus WS decreased Ls and increased Tr, Gs, and WUE. Meanwhile, WS enhanced the antioxidant capacity by increasing superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. However, WS increased malondialdehyde (MDA) content. Compared with WS, PGA plus WS enhanced the above antioxidant enzymes. In this way, PGA reduced MDA content and improved the antioxidant capacity under WS. In addition, WS decreased the shoot and root biomass, but increased the root/shoot ratio. Compared with WS, PGA plus WS further increased the root/shoot ratio and shoot and root biomass. For medical ingredients, WS decreased the yield of rosmarinic acid (RosA) and salvianolic acid B (SalB), but increased the yield of dihydrotanshinone (DHT), cryptotanshinone (CTS), tanshinone I (Tan I), and tanshinone ⅡA (Tan ⅡA). Compared with WS, PGA plus WS increased the yield of these medical ingredients. Our findings clearly suggested that PGA application was an effective method to enhance sage drought tolerance and the yield of the main medical ingredients in sage root. This provides useful information for its application in sage production under WS. Full article

Drought is becoming more prevalent and negatively affects the growth and development of barley. To explore the genetic variation in barley under drought stress, ten breeding genotypes were tested using polyethylene glycol-6000 to simulate drought conditions. We observed that drought stress significantly affected germination-related traits, depending on the specific genotypes. Some parameters, such as root length, reduced by up to 85% under drought conditions compared to the control. Overall, considering the barley growth performance, the drought tolerance index was an ideal criterion for selecting drought-tolerant genotypes, as it well characterized the gradient responses of barley genotypes to drought stress. Based on this indicator, genotype OB1878-ON-50 is recommended as a significant germplasm resource for low-precipitation regions. Full article

Subtilases (SBTs), known as serine proteases or phytoproteases in plants, are crucial enzymes involved in plant development, growth, and signaling pathways. Despite their recognized importance in other plant species, information regarding their functional roles in cultivated peanut (Arachis hypogea L.) remains sparse. We identified 122 AhSBT genes in the STQ peanut genome, classifying them into six subgroups based on phylogenetic analysis. Detailed structural and motif analyses revealed the presence of conserved domains, highlighting the evolutionary conservation of AhSBTs. The collinearity results indicate that the A. hypogea SBT gene family has 17, 5, and 1 homologous gene pairs with Glycine max, Arabidopsis thaliana, and Zea mays, respectively. Furthermore, the prediction of cis-elements in promoters indicates that they are mainly associated with hormones and abiotic stress. GO and KEGG analyses showed that many AhSBTs are important in stress response. Based on transcriptome datasets, some genes, such as AhSBT2, AhSBT18, AhSBT19, AhSBT60, AhSBT102, AhSBT5, AhSBT111, and AhSBT113, showed remarkably higher expression in diverse tissues/organs, i.e., embryo, root, and leaf, potentially implicating them in seed development. Likewise, only a few genes, including AhSBT1, AhSBT39, AhSBT53, AhSBT92, and AhSBT115, were upregulated under abiotic stress (drought and cold) and phytohormone (ethylene, abscisic acid, paclobutrazol, brassinolide, and salicylic acid) treatments. Upon inoculation with Ralstonia solanacearum, the expression levels of AhSBT39, AhSBT50, AhSBT92, and AhSBT115 were upregulated in disease-resistant and downregulated in disease-susceptible varieties. qRT-PCR-based expression profiling presented the parallel expression trends as generated from transcriptome datasets. The comprehensive dataset generated in the study provides valuable insights into understanding the functional roles of AhSBTs, paving the way for potential applications in crop improvement. These findings deepen our understanding of peanut molecular biology and offer new strategies for enhancing stress tolerance and other agronomically important traits. Full article

Plant-associated fungi often drive plant invasion success by increasing host growth, disease resistance, and tolerance to environmental stress. A high abundance of Colletotrichum asymptomatically accumulated in the leaves of Ageratina adenophora. In this study, we aimed to clarify whether three genetically distinct endophytic Colletotrichum isolates (AX39, AX115, and AX198) activate invasive plant defenses against disease and environmental stress. We observed that, in the absence of pathogen attack and environmental stress, the foliar endophyte Colletotrichum reduced photosynthesis-related physiological indicators (i.e., chlorophyll content and soluble sugar content), increased resistance-related indicators (i.e., total phenolic (TP) and peroxidase (POD) activity), and decreased the biomass of A. adenophora. However, endophytic Colletotrichum strains exhibit positive effects on resistance to certain foliar pathogen attacks. Strains AX39 and AX115 promoted but AX198 attenuated the pathogenic effects of pathogen strains G56 and Y122 (members of Mesophoma ageratinae). In contrast, AX39 and AX115 weakened, but AX198 had no effect on, the pathogenic effect of the pathogen strain S188 (Mesophoma speciosa; Didymellaceae family). We also found that endophytes increase the biomass of A. adenophora under drought or nutrient stress. Strain AX198 significantly increased stem length and chlorophyll content under drought stress. Strain AX198 significantly increased the aboveground dry weight, AX115 increased the stem length, and AX39 significantly increased the chlorophyll content under nutrient stress. Our results revealed that there are certain positive effects of foliar Colletotrichum endophytes on A. adenophora in response to biotic and abiotic stresses, which may be beneficial for its invasion. Full article

Land degradation due to salinity and prolonged drought poses significant global challenges by reducing crop yields, depleting resources, and disrupting ecosystems. Halophytes, equipped with adaptive traits for drought and soil salinity, and their associations with halotolerant microbes, offer promising solutions for restoring degraded areas sustainably. This study evaluated the effects of halophilic sulfur-oxidizing bacteria (SOB), specifically Halothiobacillus halophilus, on the physiological and biochemical responses of the halophyte Plantago coronopus L. under drought and salt stress. We analyzed the accumulation of ions (Na, Cl, K) and sulfur (S), along with growth parameters, glutathione levels, photosynthetic pigments, proline, and phenolic compounds. Drought significantly reduced water content (nearly 10-fold in plants without SOB and 4-fold in those with SOB). The leaf growth tolerance index improved by 70% in control plants and 30% in moderately salt-stressed plants (300 mM NaCl) after SOB application. SOB increased sulfur content in all treatments except at high salinity (600 mM NaCl), reduced toxic sodium and chloride ion accumulation, and enhanced potassium levels under drought and moderate salinity. Proline, total phenolic, and malondialdehyde (MDA) levels were highest in drought-stressed plants, regardless of SOB inoculation. SOB inoculation increased GSH levels in both control and 300 mM NaCl-treated plants, while GSSG levels remained constant. These findings highlight the potential of SOB as beneficial microorganisms to enhance sulfur availability and improve P. coronopus tolerance to moderate salt stress. Full article

Drought stress is a major environmental constraint that limits rice (Oryza sativa L.) production worldwide. In this study, we investigated the effects of drought stress at the booting stage on rice leaf physiological characteristics and yield. The results showed that drought stress would lead to a significant decrease in chlorophyll content and photosynthesis in rice leaves, which would affect rice yield. Three different rice varieties were used in this study, namely Hanyou73 (HY73), Huanghuazhan (HHZ), and IRAT109. Under drought stress, the chlorophyll content of all cultivars decreased significantly: 11.1% and 32.2% decreases in chlorophyll a and chlorophyll b in HHZ cultivars, 14.1% and 28.5% decreases in IRAT109 cultivars, and 22.9% and 18.6% decreases in HY73 cultivars, respectively. In addition, drought stress also led to a significant decrease in leaf water potential, a significant increase in antioxidant enzyme activity, and an increase in malondialdehyde (MDA) content, suggesting that rice activated a defense mechanism to cope with drought-induced oxidative stress. This study also found that drought stress significantly reduced the net photosynthetic rate and stomatal conductance of rice, which, in turn, affected the yield of rice. Under drought stress, the yield of the HHZ cultivars decreased most significantly, reaching 30.2%, while the yields of IRAT109 and HY73 cultivars decreased by 13.0% and 18.2%, respectively. The analysis of yield composition showed that the number of grains per panicle, seed-setting rate, and 1000-grain weight were the key factors affecting yield formation. A correlation analysis showed that there was a significant positive correlation between yield and net photosynthetic rate, stomatal conductance, chla/chlb ratio, Rubisco activity, and Fv/Fm, but there was a negative correlation with MDA and non-photochemical quenching (NPQ). In summary, the effects of drought stress on rice yield are multifaceted, involving changes in multiple agronomic traits. The results highlight the importance of selecting and nurturing rice varieties with a high drought tolerance, which should have efficient antioxidant systems and high photosynthetic efficiency. Future research should focus on the genetic mechanisms of these physiological responses in order to develop molecular markers to assist in the breeding of drought-tolerant rice varieties. Full article

Plants require adequate water for growth, development, and reproduction. Peptides play a key role in plant growth and development and act in a similar manner to plant hormones. However, only a few peptides have been identified to play a role in abiotic stress tolerance in potato. In this study, we identified fourteen members of the epidermal patterning factor (EPF) family in potato, which were designated as StEPF1-14 according to their chromosomal locations. We also conducted a comprehensive analysis of their chromosomal distribution, gene structures, physicochemical properties, phylogenetic relationships, and tissue-specific expression patterns. RT-qPCR analysis revealed that the StEPF4 gene is significantly induced by drought stress, suggesting its potential role as a negative regulator in the plant’s response to drought. Furthermore, multiple cis-regulatory elements associated with drought-responsive regulation were identified within the promoter region of the StEPF genes. Here, we isolated an EPF secreted Cys-rich small peptide StEPF4 from ‘Atlantic’ and explored its mechanism in plant response to drought stress. We found that StEPF4 was greatly induced by dehydration treatment in potato. To investigate its potential biological functions, StEPF4 was knocked down in potato. The StEPF4 knocked down lines (KdStEPF4) significantly decreased stomatal density, resulting in a decrease in the transpiration rate. KdStEPF4 lines maintained a higher photosynthetic rate and lowered the water loss rate of leaves compared with the control, resulting in increased drought resistance. Taken together, this study provides detailed information about StEPFs, and our findings also show that StEPF4 plays an essential role in regulating drought resistance by reducing stomatal density in potato. Full article

The trihelix transcription factor, which is a plant-specific family, play a critical role in plant growth and development and stress responses. Drought is the main limiting factor affecting yield of maize (Zea mays). However, the identification and characterization of this gene family in maize and its biological functions in response to drought stress have not been reported. Here, 46 Zea mays trihelix genes (ZmTHXs) were identified in the genome. Phylogenetic analysis of the ZmTHXs revealed that the genes were clustered into five subfamilies: GT-1, GT-2, GTγ, SH4, and SIP1. Chromosomal localization analysis showed that the 46 ZmTHXs were unevenly distributed across 10 chromosomes in maize. Cis-acting elements related to abiotic stress in ZmTHXs were found. Most ZmTHXs genes showed significant changes in expression levels under drought treatment. In addition, ZmTHX15-overexpressing Arabidopsis exhibited stronger drought tolerance with less secondary oxidative damage and higher photosynthetic rate. These findings could serve as a basis for future studies on the roles of ZmTHXs and the potential genetic markers for breeding stress-resistant and high-yielding maize varieties. Full article