Silicon-mediated drought tolerance in Vigna mungo through coordinated regulation of aquaporin genes, plant water relations and photosynthetic processes.
Investigation of the role of silicon in mitigating drought-induced damage in two mash bean cultivars found it significantly enhances drought tolerance in mash bean by improving photosynthesis efficiency, antioxidant capacity, and molecular regulation of water transport.
Abstract
Drought stress restricts growth and productivity in grain legumes, yet the integrative mechanisms underlying silicon-mediated drought tolerance in Vigna mungo (mash bean) remain poorly understood. The present study aimed to investigate the role of silicon in mitigating drought-induced damage in two mash bean cultivars. To evaluate this effect, plants were subjected to different drought regimes with and without silicon. Data on growth traits, biomass accumulation, reproductive attributes, photosynthetic gas exchange parameters, water relations, antioxidant enzyme activities, phenolic compounds, nutrient dynamics, and expression of drought-responsive genes were collected and statistically analyzed. Multivariate analyses, including PCA and structural equation modeling (SEM), were used to elucidate relationships among measured variables. Drought significantly reduced plant growth, biomass production, and reproductive traits, accompanied by marked declines in net assimilation rate (up to 35-40%), stomatal conductance, and transpiration under 25% field capacity (FC). In contrast, drought increased WUE (49.7-56.2 µmol CO₂ mmol⁻1 H₂O), antioxidant enzyme activities, and phenolic accumulation. Silicon supplementation substantially improved plant growth, restored photosynthetic performance, and enhanced antioxidant defense under drought conditions. Si-treated plants exhibited increased activities of SOD, CAT, and APX, higher phenolic content, improved water status, and upregulated expression of DREB2A, PIP2-1, and TIP4-1 compared with non-supplemented plants. Multivariate analyses clearly separated drought and Si treatments, while SEM revealed strong relationships linking gene expression, biochemical defense systems, physiological processes, and plant growth responses. In conclusion, silicon supplementation significantly enhances drought tolerance in mash bean by improving photosynthetic efficiency, antioxidant capacity, and molecular regulation of water transport.
Plant biostimulants encompass diverse biologically active substances that enhance growth and stress tolerance through mechanisms beyond direct mineral nutrition. This study aimed to elucidate the mode of action of a phosphorus-based biostimulant (MCT-P) and its effects under drought stress in corn (Zea mays), lettuce (Lactuca sativa), and Arabidopsis thaliana. Standardized bioassays evaluated root morphology, biomass, nutrient uptake, sugar metabolism, gene expression (TOR, H+-ATPase, LAX3), photosynthetic pigments, and chlorophyll fluorescence under optimal and drought conditions. MCT-P significantly improved root architecture, biomass accumulation, nutrient acquisition, leaf sugar content, and root sugar exudation, while modulating growth-related gene expression and enhancing photosynthetic performance and drought tolerance. These results suggest that MCT-P acts as a biostimulant by integrating humic-like bioactivity with phosphorus-mediated metabolic regulation, promoting coordinated carbon–nutrient–energy responses that support plant growth and resilience under water-limited conditions.
M. P. Santos, Jason Gralian, Aletia James et al.· Discover Plants· 0 citations
Calcium (Ca) functions as a secondary messenger and contributes to plant drought tolerance. This study examined how Ca supplementation influences photosynthetic performance and growth in Glycyrrhiza uralensis seedlings under drought stress. Drought significantly reduced net photosynthetic rate, stomatal conductance, and transpiration rate. Under severe drought, photosynthesis was primarily constrained by non-stomatal limitations, indicating damage to the photosynthetic apparatus. Ca supplementation partially restored gas exchange and alleviated drought-induced photoinhibition by mitigating the decline in maximum PSII efficiency. Drought also reduced growth and root yield (plant height, basal diameter, crown area, root length), whereas Ca supplementation promoted seedling growth and alleviated drought-related damage, thereby enhancing overall drought adaptability. These findings demonstrate that Ca plays a key role in maintaining photosynthetic function and alleviating photodamage under water-limited conditions. Appropriate Ca supplementation may therefore serve as a practical strategy to improve drought tolerance and support the sustainable cultivation of G. uralensis in arid and semi-arid regions.
Enjun Wang, Pengbin Dong, Na Bai et al.· Scientific Reports· 0 citations
Soil salinity is a major abiotic stress that severely limits plant growth and productivity worldwide, particularly under changing climate conditions. Silicon (Si) has emerged as a promising approach for improving plant tolerance to salinity stress; however, its integrated physiological effects in perennial forage grasses remain insufficiently understood. This study investigated the role of Si in alleviating salinity stress in
Agropyron cristatum
×
A. desertorum
cv. Hycrest-Mengnong under controlled conditions. Plants were exposed to 0, 100, and 200 mM NaCl with or without Si application, and growth, physiological, biochemical, and ionic responses were evaluated. Salinity stress significantly reduced plant height, biomass, leaf area, photosynthetic performance, chlorophyll content, and PSII efficiency, with the strongest inhibitory effects observed at 200 mM NaCl. Salinity also increased oxidative damage, as indicated by higher malondialdehyde (MDA) content, promoted proline accumulation associated with osmotic adjustment, enhanced antioxidant enzyme activities, and disrupted ionic homeostasis through excessive Na⁺ accumulation and reduced K⁺/Na⁺ ratio. Si application markedly alleviated these adverse effects by improving growth, maintaining photosynthetic efficiency and chlorophyll stability, enhancing antioxidant defense, promoting osmotic adjustment, and regulating ion balance through reduced Na⁺ accumulation and improved K⁺ retention. These findings demonstrate that Si enhances salinity tolerance through coordinated regulation of physiological, biochemical, and ionic mechanisms. The study provides a mechanistic framework for understanding Si-mediated salinity tolerance in perennial forage grasses and highlights the potential application of Si for improving forage productivity under saline conditions.
Aneela Bashir, Ansar Abbas, Xiaohong Li et al.· Plant growth regulation (Pri...· 0 citations
Drought is a major abiotic stress that severely limits cotton productivity by reducing growth, yield, and fiber quality. Understanding genotype-specific responses to reproductive-stage drought is essential for identifying reliable selection traits and improving drought resilience in cotton breeding programs. This study evaluated 54 cotton genotypes at the flowering stage under three irrigation regimes: well-watered conditions (80% FC), mild drought stress (60% FC), and severe drought stress (40% FC). Morphological traits (root and shoot biomass), physiological traits (photosynthetic rate, leaf water loss, and relative water content), and biochemical traits (proline, soluble sugars, amino acids, antioxidant enzyme activities, and reactive oxygen species) were assessed. Drought treatments were imposed for three consecutive weeks during flowering to investigate genotype responses to varying levels of water deficit. The experiment was conducted in a rain-out shelter using a factorial completely randomized design (CRD) with three replications for each genotype–treatment combination. Cotton accessions were grown in plastic containers. Significant genotype-dependent variation was observed across all drought treatments, with responses becoming more pronounced under severe stress. Two-way analysis of variance revealed that drought significantly affected all measured traits. Descriptive statistics and boxplot analyses further illustrated variations in trait performance among genotypes under different stress levels. Principal component analysis (PCA) revealed clear phenotypic divergence among genotypes and highlighted trait associations under contrasting water regimes. Heatmap analysis further confirmed genotype grouping patterns and their relationships with the evaluated traits. Moreover, MGIDI-based selection at 15% selection intensity identified G
33
(FH-901), G
50
(N-1048), G
53
(N-135), G
36
(FH-Super-Cotton), G
29
(FH-556), G
47
(MNH-1035), G
54
(N-135-BB-121/38), and G
41
(IUB-13) as drought-tolerant genotypes based on their lower MGIDI values and favorable performance. These genotypes exhibited superior performance, greater water retention, lower oxidative damage, and stronger antioxidant defense systems under water-deficit conditions. The findings provide valuable insights for cotton breeding programs aimed at developing drought-resilient cultivars and support sustainable cotton production in water-limited environments.
M. Y. Shani, A. Ditta, Muhammad Kashif Riaz Khan· Scientific Reports· 0 citations
It is suggested that StuPPO9 confers drought resilience through a multi-layered network involving optimized carbon allocation, reinforced cell wall integrity, and enhanced ROS scavenging capacity.
Ming-Kun Chi, Bo Liu, Heng-Zhao Yang et al.· Plants· 0 citations
Yield losses due to water-deficit (WD) conditions, especially during the reproductive stages of plant development, pose a significant threat to global canola (Brassica napus L.) production. Therefore, it is critical to investigate traits contributing to improved productivity under increased WD conditions. Here we present phenotypic, physiological and transcriptomic changes in response to WD across contrasting canola accessions exhibiting variation in drought resistance-related traits. WD significantly reduced shoot biomass, plant height, harvest index, leaf water content, photosynthetic CO2 assimilation rate, intrinsic water-use efficiency and carbon isotope discrimination. WD caused 49 to 100% of the seed yield reduction: the minimum seed yield reduction (49.66%) was observed in a doubled-haploid (DH) line, 06-5101.137, while the maximum yield reduction (94.1 to 100%) occurred in the late-flowering DH lines (06.5101.088, 06-5101.306). Seed yield showed a positive correlation (r = 0.35 to 0.97) with shoot biomass, plant height, harvest index, leaf water content, photosynthetic CO2 assimilation rate, intrinsic water use efficiency and carbon isotope discrimination. However, it showed negative correlations with days to flower, specific leaf weight, root length and root biomass (r = −0.08 to −0.80) across water treatments. The leaf transcriptome analysis of the two parental lines of DH population that exhibit variation for effective water use under well-watered and water-deficient conditions revealed different categories of differentially expressed genes (DEGs): WD-responsive DEGs in BC1329 parental line (1116) and BC9102 (1205) with 754 and 853 DEGs unique to BC1329 and BC9102, respectively, WD-responsive DEGs (906), genotype-dependent DEGs (8465) and genotype × treatment interaction DEGs (353). DEG annotations revealed that the WD-treatment-affected genes were involved in stress responses and growth and development. We further located 235 DEGs within the QTL regions underlying agronomic and physiological performance. Our study provides a conceptual framework for the morphological, physiological and molecular determinants involved in water-use efficiency. Seedlings’ traits with high heritability values, such as shoot biomass, leaf weight, leaf water content and Δ13C, serve as proxies for trait-based selection for improved seed yield under both water-limited and non-water-limited conditions.
H. Raman, B. McVittie, Niharika Sharma et al.· International Journal of Mol...· 0 citations
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