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Submerged macrophytes play a crucial role in the ecological restoration of water bodies, and their restoration capacity is closely related to the underwater lighting conditions. This study explored the effects of underwater lighting time on the growth characteristics of Vallisneria spinulosa Yan (V. spinulosa) and its water restoration process. V. spinulosa achieved a higher Fv/Fm (0.64), ETRmax (10.43), chlorophyll content (0.85 mg/g), and removal efficiency of total phosphorus (0.37 × 10⁻³ g m⁻³ d⁻¹) and a lower algal abundance with a longer lighting time (18 h every day). However, a higher removal efficiency of NH₄⁺–N and TN was obtained with a shorter lighting time (6–12 h every day). The lighting time showed a significance influence on the microbial community of the V. spinulosa growth system, and the influence was significantly different in different regions. Temperature and electrical conductivity were the main environmental impact factors for the microbial community under different lighting times. The abundances of Proteobacteria, Bacteroidota, and Verrucomicrobia exhibited a great positive correlation with each other and a strong positive correlation with the two factors. In addition, the lighting time had a strongly significant correlation with the physical and chemical characteristics of the water environment (p < 0.001) and a significant correlation with the growth characteristics of V. spinulosa (p < 0.05). Full article

The loss of agricultural land is one of the main problems facing the global agricultural sector, and it is related to multiple phenomena; one of the main causes is soil salinization, induced both by natural processes and human activities. Among the strategies adopted to deal with soil salinization and its mitigation, the cultivation of species able to survive in saline soils seems to be an effective way of making salt-compromised lands usable. Iris pallida is a rustic plant and a species of high economic value that is mostly cultivated for perfume production. Consequently, the application of I. pallida to cover soils not suitable for crops traditionally cultivated for human and livestock nutrition could be considered; therefore, a preliminary test on the capacity of I. pallida to tolerate salinity during the acclimatization phase of micropropagated plants was conducted. Plantlets were treated with exogenous melatonin during the in vitro phase by adding it to the culture medium; therefore, during the acclimatization phase, crescent salt doses (150, 300, and 400 mM) were added to the soil every 14 days, administering melatonin to plants by a spray solution 24 h before each salt addition. At the end of the experiment, biometric measurements, chlorophylls, carotenoids, and macro-element contents were measured, and the relative water content (RWC) was determined in each salt addition. The results showed that orris plants can survive soil salt concentrations of up to 400 mM, and that the 50 µM melatonin spray treatment can protect orris rhizomes from salt side effects. Full article

To gain a deeper understanding of the mechanisms by which cushioning packaging preserves the quality of Chinese olive fruits during cold chain transportation and extends their shelf life, this study simulated cold chain conditions and investigated the effects of cushioning packaging on the physiology, antioxidant capacity, and secondary metabolites of fruits during a 20-day shelf life. The results indicated that the decay rate in cushioning-packaging-treated fruit was 75% lower than that in the unbuffered packaging fruit at day 20 of shelf life. Simultaneously, cushioning packaging treatment mitigated the damage severity of the cell membrane structure and kept the cell membrane permeability at a low level, which was 15.34% lower than that in the unbuffered packaging fruit at day 20 of shelf life. Additionally, cushioning packaging effectively restrained the increases in malondialdehyde (MDA) content and alleviated the decline in chlorophyll and total flavonoid contents. It kept a balance among reactive oxygen species (ROS), antioxidant levels, and antioxidant enzyme activities, thereby reducing mechanical-damage-induced decay rates in Chinese olive fruits during the shelf life. Furthermore, metabolome analysis of Chinese olives during the shelf life was performed comparing those without buffered packaging to those with buffered packaging. The metabolome analysis found that the flavonoid biosynthetic pathway exhibited a higher accumulation of chrysin, neohesperidin, naringenin chalcone, sakuranetin, quercetin, catechin, and naringenin metabolites in cushion-packaging treatment compared to those without cushioning treatment. Furthermore, within the phenylalanine metabolic pathway, the accumulation of phenylalanine, p-coumaraldehyde, p-coumaric acid, coniferin and caffeoyl quinic acid metabolites was significantly higher in buffered-packaging groups compared to those without buffering. Together, these findings suggest that cushioning packaging can effectively sustain the integrity of cell membranes and enhance the shelf-life quality of Chinese olive fruits by regulating the balance of ROS and mitigating oxidative stress during cold chain transportation. Full article

In the present work, we examined the effects of exogenous abscisic acid (ABA) under ultraviolet B (UV-B) exposure on gibberellin (GA) production, signaling, and antioxidant-related genes in Rhododendron chrysanthum Pall (R. chrysanthum). Using transcriptomics, acetylated proteomics, and widely targeted metabolomics, the effects of UV-B stress on R. chrysanthum and the regulatory effects of exogenous ABA on it were revealed from multiple perspectives. The findings revealed that R. chrysanthum’s antioxidant enzyme genes were differentially expressed by UV-B radiation and were substantially enriched in the glutathione metabolic pathway. Exogenous ABA supplementation boosted plant resistance to UV-B damage and further enhanced the expression of antioxidant enzyme genes. Furthermore, under UV-B stress, glutathione reductase, glutathione peroxidase, and L-ascorbate peroxidase were found to be the primary antioxidant enzymes controlled by exogenous ABA. In addition, gibberellin content was altered due to UV-B and exogenous ABA treatments, with greater effects on GA3 and GA53. The acetylation proteomics study’s outcomes disclosed that the three main oxidative enzymes’ acetylation modifications were dramatically changed during UV-B exposure, which may have an impact on the antioxidant enzymes’ functions and activities. The protective impact of exogenous ABA and gibberellin on R. chrysanthum’s photosynthetic system was further established by measuring the parameters of chlorophyll fluorescence. This research offers a theoretical foundation for the development of breeding highly resistant plant varieties as well as fresh insights into how hormone levels and antioxidant systems are regulated by plants in response to UV-B damage. Full article

Biological remediation of agricultural soils contaminated with oil is complicated by the presence of residual amounts of chemical plant protection products, in particular, herbicides, which, like oil, negatively affect the soil microbiome and plants. In this work, we studied five strains of bacteria of the genera Pseudomonas and Acinetobacter, which exhibited a high degree of oil biodegradation (72–96%). All strains showed resistance to herbicides based on 2,4-D, imazethapyr and tribenuron-methyl, the ability to fix nitrogen, phosphate mobilization, and production of indole-3-acetic acid. The presence of pollutants affected the growth-stimulating properties of bacteria in different ways. The most promising strain P. citronellolis N2 was used alone and together with oat and lupine plants for soil remediation of oil, including herbicide-treated oil-contaminated soil. Combined contamination was more toxic to plants and soil microorganisms. Bacterization stimulated the formation of chlorophyll and suppressed the synthesis of abscisic acid and malonic dialdehyde in plant tissues. The combined use of bacteria and oat plants most effectively reduced the content of hydrocarbons in the soil (including in the presence of herbicides). The results obtained can be used to develop new methods for bioremediation of soils with polychemical pollution. Full article

The growth and development of plants are closely tied to growth stages, such as germination, flower bud differentiation, photosynthesis, water and fertilizer use efficiency, stress resistance, etc. Previous studies on the stress resistance of plants with different leaf stages have primarily focused on single-factor environmental conditions. However, there has been a lack of systematic research on the physiology of plant seedlings under combined high-temperature and high-humidity (HH) stress, and the relationship between cucumber growth stages and HH tolerance remains unclear. In this study, we analyzed the phenotype, photosynthetic characteristics, reactive oxygen species content, and antioxidant enzyme activity of cucumber seedlings at 1-, 2-, 3-, and 4-leaf stages under control (25 °C + 80%RH, CK) and HH (42 °C + 95%RH) stress, aiming to clarify the relationship between growth stage and cucumber HH tolerance. The results indicated that the HH tolerance of cucumber seedlings increases with leaf stage. Seedlings at 1-leaf and 2-leaf stages were most sensitive to HH, whereas 4-leaf seedlings showed the greatest tolerance. Under HH stress, the biomass, chlorophyll content, net photosynthetic rate, and photosynthetic electron transfer rate were significantly reduced compared to CK. Simultaneously, there was an increase in reactive oxygen species content and antioxidant enzyme activity. The relative values for dry weight, total chlorophyll content, net photosynthetic rate, Fv/Fm, qP, ETR, and Y (II) in 1-leaf and 2-leaf seedlings were significantly lower, while ROS accumulation and changes in antioxidant enzyme activity were significantly higher compared to 4-leaf seedlings. This lays a foundation for future studies on the growth and physiological response of cucumber plants at different growth stages under varying temperature and humidity combined stresses. Full article

Salt stress affects the growth, metabolism, yield, and quality of crops. To adapt to high-salt environments, plants form various regulatory mechanisms. Salt over sensitive (SOS) is the key gene of SOS signal transduction pathway. As a member of the SOS3 subfamily, the function of SOS3-3 under salt stress has not been reported. To verify the function of SOS3-3 and the morphological and physiological parameters, the expression of genes related to stress were compared between the SOS3-3 overexpressed (OESOS3-3) and silenced tomato (VSOS3-3) at control and 10 days’ NaCl treatment. The results showed that, compared with the control (Ve), the plants of VSOS3-3 were shorter under salt stress, with curled leaves and abscission. The fresh and dry weights, F_v/F_m, total chlorophyll content, antioxidant enzyme activities, and proline content of VSOS3-3 significantly decreased, while the relative conductivity, hydrogen peroxide (H₂O₂), and Malondialdehyde (MDA) content of VSOS3-3 plants significantly increased compared to that of WT, respectively. Compared to the wild-type (WT), OESOS3-3 plants were less damaged by salt stress, with significantly higher plant height, fresh and dry weights, F_v/F_m, total chlorophyll content, antioxidant enzyme activity, and proline content. However, the relative conductance, H₂O₂, and MDA content were significantly lower in OESOS3-3 than WT. The expression levels of SOS1, SOS2, LKT1 (ion transport-related gene), APX1 (ROS signaling pathway-related gene), P5CS (osmoregulation-related gene), and ABF4 (ABA signaling pathway-related gene) were significantly lower in VSOS3-3 than Ve, but significantly higher in OESOS3-3 than in WT. These results suggested that SOS3-3 regulate salt tolerance by influencing physiological and biochemical changes and the expression of genes related to stress response. This study revealed the mechanism of SOS family participating in regulating tomato salt tolerance, providing a theoretical basis for improving tomato salt tolerance. Full article

In recent years, pigment rice has been the focus of much attention due to its high nutritional value and ornamental value. To gain a better understanding of pigmented rice, we studied the morphological, physiological, and yield characteristics of four varieties, i.e., light green (LG), deep purple (DP), black-purple (BP), and white rice (WR), as plant material. The field experiment was conducted using a randomized complete block design at Guangdong ocean university research farm during 2023 and 2024. The data of the pigmented rice varieties regarding their morphological, physiological, and antioxidant traits were compared with CK. Leaf area and dry matter accumulation were significantly higher in BP than in the other rice varieties, with BP being the best performer and WR being the worst. The internode length, leaf area, and dry matter accumulation of BP were markedly higher than the rest of the rice varieties. The chlorophyll content of BP was significantly higher. The antioxidant enzyme activities were significantly different among all the varieties. The antioxidant enzyme activities of BP were significantly higher than those of the other rice varieties. Seed yield varied significantly, with BP showing the highest yield. The morphophysiological characteristics of BP and DP suggest that these two varieties can alleviate the response to salinity stress, thereby increasing rice yield. Full article

The brown alga Sargassum fusiforme (SF) is historically consumed as a food material in Japan. A steaming process is often required for SF products on the market due to their moderate hardness and astringent taste. This investigation aimed to elucidate the effect of steaming on the anti-diabetic activity of SF and its related chemical components. Acetone extracts of SF were prepared after it were steamed for 0, 1, 2, or 4 h (SF-0h, SF-1h, SF-3h, and SF-4h, respectively). Alpha-glucosidase inhibitory profiles of each SF extract were made based on activity-guided separation. The active fractions were collected and NMR was applied for a further chemical composition analysis. Our results suggested that total polyphenol levels decreased drastically after steaming, which resulted in a drop in α-glucosidase inhibitory activity. The fatty acid, pheophytin a, and pyropheophytin a contents were elevated significantly after steaming, which contributed to the majority of the activity of steamed SF (SF-1h). However, prolonging the steaming time did not significantly affect the activity of SF further since the content of free fatty acids in steamed SF (SF-2h and SF-4h) almost did not change with a longer time of steaming. Moreover, palmitic acid, 8-octadecenoic acid, and tetradecanoic acid were identified as the top three important fatty acids for the inhibition of α-glucosidase by steamed SF. Further molecular docking results revealed that these fatty acids could interact with residues of α-glucosidase via hydrogen bonds, salt bridges, and hydrophobic interactions. In conclusion, steaming altered the α-glucosidase inhibitory properties of SF by changing the contents of polyphenols, fatty acids, and chlorophyll derivatives. Full article

Leaf spot disease has become a significant limitation in oat production. 24-epibrassinolide (EBR), a highly active brassinosteroid, plays a significant role in enhancing plant immunity against various diseases by modulating physiological and molecular responses. However, the exact mechanisms by which exogenous EBR regulates plant defense to leaf spot disease are still largely unknown. In this study, we applied various concentrations of EBR (0, 0.01, 0.1, 1, and 10 mg·L⁻¹) to the leaves of oat plants that were inoculated with the Drechslera avenae pathogen. The application of 1 mg·L⁻¹ EBR significantly decreased disease index and increased chlorophyll content under pathogen inoculation while also enhancing antioxidant enzyme (SOD, CAT, and APX) activity and reducing pathogen-induced O₂^•− production rate and MDA content. Moreover, the enzymes associated with phenylpropanoid metabolism, such as PAL, C4H, and 4CL, were significantly activated by exogenous EBR. Our transcriptomic analyses further revealed that the combination of exogenous EBR and pathogen inoculation upregulated genes involved in signal transduction (BR, ABA, and MAPK), antioxidant enzyme defense systems, and phenylpropanoid and lignin-specific pathways, such as BAS1, APX, GPX, PAL, C4H, 4CL, CCR1, and CAD. Together, these findings reveal that exogenous BR application can improve resistance to Drechslera avenae-induced leaf spot disease in oats by regulating antioxidant defense systems and phenylpropanoid metabolism, which may have the potential to control leaf spot disease in oat production. Full article

Previous studies have shown that there are significant sexual differences in the physiological responses of Torreya grandis to environmental stress. However, little is known about its sex-specific differences in response to salt stress against the background of nitrogen (N) deposition. In this experiment, two-year-old male and female T. grandis seedlings were used as experimental materials and exposed to moderate salt conditions and different N levels to study the effects of nitrogen addition and salt stress on the chlorophyll content, chlorophyll fluorescence parameters, antioxidant system, and leaf stoichiometry of T. grandis seedlings. With the increase in nitrogen content, the contents of proline, malondialdehyde, superoxide anion, and H₂O₂ in the leaves of T. grandis seedlings under salt conditions gradually increased. The contents of these four metabolites in the leaves of male T. grandis seedlings were almost all higher than those of the female ones. Compared with the control group, the contents of enzymatic and non-enzymatic antioxidants increased under N addition treatments, especially for the low and moderate N addition groups. The results showed that moderate concentrations of N addition can mitigate the damage caused by salt, while high concentrations of nitrogen do not. Under conditions of salt and nitrogen addition, female T. grandis seedlings outperformed male ones, as evidenced by their higher photosynthetic pigment content, enhanced antioxidant enzyme activity, reduced accumulation of intracellular cytotoxic metabolites, and higher carbon and nitrogen content in their leaves compared to those of male seedlings. The findings of this research will contribute to our understanding and offer a theoretical foundation for the cultivation of T. grandis seedlings in environments with nitrogen deposition and salinization. Full article

Excessive irrigation of saline-alkaline soils with Cd-contaminated wastewater has resulted in deterioration of both soil and plant quality. To an investigate this, a study was conducted to explore the effects of biochar (applied at 10 t ha⁻¹), PGPRs (Bradyrhizobium japonicum (USDA 110) + Trichoderma harzianum at 1:1 ratio), and Si-NPs (25 mg L⁻¹) on soybean plants grown in saline-alkali soil irrigated with wastewater. The results showed that the trio-combination of biochar with PGPRs, (as soil amendments) and Si-NPs (as foliar spraying), was more effective than individual or coupled applications in reducing Cd bioavailability in the soil, minimizing its absorption, translocation and bioconcentration in soybean tissues. The trio-combination reduced Cd bioavailability in the soil by 39.1% and Cd accumulation in plant roots, shoots, and seeds by 61.0%, 69.3%, and 61.1%, respectively. Physiological improvements in soybean plants were also observed, including 197.8% increase in root growth, 209.3% increase in chlorophyll content, and 297.4% increase in carotenoid levels. The trio-combination significantly improved soil physicochemical characteristics, enhanced soil microbial indicators and boosted soil enzymes activity, which in turn facilitated nutrient uptake and increased antioxidant enzymes activity. These positive outcomes enhanced photosynthesis, improved productivity and increased seed nutritional value. Overall, the trio-combination of biochar with PGPRs and Si-NPs are considered a reliable approach not only for revitalizing soybean growth but also for immobilizing Cd and improving soil health under wastewater irrigation. Full article

Three different types of common halophytes (Haloxylon ammodendron, Tamarix chinensis, and Phragmites australis) in northwest China were used in this study. A field experiment approach was adopted, involving five solutions with different salt concentrations (0, 150, 200, 250, and 300 mmol·L⁻¹) for salt stress treatment. The changes in photosynthetic characteristics and physiological characteristics of three different types of halophytes and their relationship with biomass were measured and analyzed. The results showed that (1) with the increase in salt concentration, the plant height, stem diameter, and biomass of three halophytes showed a downward trend. (2) The chlorophyll a, chlorophyll b, and total chlorophyll contents of Haloxylon ammodendron and Tamarix chinensis first increased and then decreased with the increase in salt concentration. Phragmites australis showed a decreasing trend. The malondialdehyde content of three halophytes showed a clear increasing trend. (3) Under different salt concentrations, the diurnal changes in the net photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency of three different types of halophytes all showed an “M” trend. The diurnal variation in intercellular carbon dioxide concentration showed a “W” trend. (4) With the increase in salt concentration, the daily average values of the net photosynthetic rate, transpiration rate, and stomatal conductance of three different types of halophytes showed a downward trend. The daily average value of intercellular carbon dioxide concentration showed a “V”-shaped trend of first decreasing and then increasing. The daily average value of water use efficiency showed a “single peak” trend of first increasing and then decreasing. Haloxylon ammodendron and Phragmites australis were mainly limited by stomata at a salt concentration of 0~200 mmol·L⁻¹ and were mainly limited by non-stomata at a salt concentration of 250~300 mmol·L⁻¹. Tamarix chinensis is mainly limited by stomata at a salt concentration of 0~250 mmol·L⁻¹ and is mainly limited by non-stomata at a salt concentration of 300 mmol·L⁻¹. Compared with Haloxylon ammodendron and Phragmites australis, Tamarix chinensis has better water use efficiency, salt tolerance, and adaptability. (5) Meteorological factors, growth morphological factors, physiological factors, photosynthetic factors, and salt concentration have higher explanatory degrees, which have significant effects on the biomass of halophytes. Among them, salt concentration and growth morphological factors have direct core driving effects on the biomass of three different types of halophytes, while meteorological factors, photosynthetic factors, and physiological factors have different effects due to the differences in and complexity of halophytes. This study can provide a theoretical basis for further revealing the adaptation mechanism of different halophytes to salt stress. Full article

This study accurately inverts key growth parameters of rice, including Leaf Area Index (LAI), chlorophyll content (SPAD) value, and height, by integrating multisource remote sensing data (including MODIS and ERA5 imagery) and deep learning models. Dehui City in Jilin Province, China, was selected as the case study area, where multidimensional data including vegetation indices, ecological function parameters, and environmental variables were collected, covering seven key growth stages of rice. Data analysis and parameter prediction were conducted using a variety of machine learning and deep learning models including Partial Least Squares (PLSs), Support Vector Machine (SVM), Random Forest (RF), and Long Short-Term Memory Networks (LSTM), among which the LSTM model demonstrated superior performance, particularly at multiple critical time points. The results show that the LSTM performed best in inverting the three parameters, with the LAI inversion accuracy on 21 August reaching a coefficient of determination (R²) of 0.72, root mean square error (RMSE) of 0.34, and mean absolute error (MAE) of 0.27. The SPAD inversion accuracy on the same date achieved an R² of 0.69, RMSE of 1.45, and MAE of 1.16. The height inversion accuracy on 25 July reached an R² of 0.74, RMSE of 2.30, and MAE of 2.08. This study not only verifies the effectiveness of combining multisource data and advanced algorithms but also provides a scientific basis for the precision management and decision-making of rice cultivation. Full article

Air pollution, particularly particulate matter (PM), poses a significant threat to urban environments and public health. This study aims to explore the impact of small-scale spatial and height variations on the ability of different roadside tree species: Tilia cordata Mill., Platanus × hispanica Mill. ex Münchh., and Sorbus intermedia (Ehrh.) Pers., to accumulate PM, providing insights for enhancing urban sustainability. Conducted along a high-traffic road in Warsaw, Poland, the research examines PM accumulation at varying heights and locations within tree canopies while also evaluating the influence of PM on photosynthetic efficiency. Results indicate substantial differences in PM accumulation between tree species and height ranges, with S. intermedia accumulating the highest PM levels. PM accumulation was greatest near the roadside and at lower canopy heights (1–1.5 m), while higher canopies and areas distant from the road showed reduced PM concentrations. T. cordata exhibited the highest PM accumulation on the side facing traffic, averaging 12% at 1–1.5 m height, while the interior recorded 5% at 2–2.5 m height. In S. intermedia, the roadside crown contributed the highest accumulation (14%) at 1–1.5 m height and only 6% on the side facing departing traffic at 2–2.5 m height. P. hispanica displayed higher efficiency in PM accumulation, reaching 11% at the roadside (1–1.5 m) and 7% at the top of the crown (3–3.5 m). Additionally, PM accumulation negatively impacted photosynthetic efficiency and chlorophyll content, with the highest PM levels correlating with reduced plant vitality. PCA analysis showed a stronger association between leaf-deposited PM and total chlorophyll content and that the presence of accumulated PM may significantly influence the chlorophyll content of the plants. These findings provide valuable guidance for urban planners in strategically planting roadside vegetation to maximize air quality improvement, offering a cost-effective and sustainable approach to mitigate urban pollution. Full article