Search Results (408)

This study investigated alternative pathways involving adaptive traits associated with drought tolerance in popcorn cultivated under soil water restriction through path analysis. Direct and indirect effects were estimated for morpho-agronomic variables, including ear height (EH), grain number per ear (GNE), grain number per row (GNR), 100-grain weight, grain yield (GY), and popping expansion (PE); physiological variables, such as relative chlorophyll content, anthocyanin and flavonoid indices, and maximum quantum efficiency of photosystem II; and root-related traits, including brace- and crown-root number and root angle. Fifty popcorn inbred lines were assessed under contrasting water conditions (WC), namely well-watered and water-stressed environments, during two crop seasons (CS). Water restriction was imposed before male anthesis, and the permanent wilting point was reached at 63 days after sowing in CS-2020 and at 100 days in CS-2021. Significant genotype × WC × CS interactions were identified for all evaluated traits. The effects of drought varied according to the developmental stage at which stress occurred. Under both water regimes, indirect selection through EH and GNR favored gains in GY, whereas EH and GNE showed the strongest indirect contributions to PE. Among the evaluated variables, EH emerged as a promising trait for indirect selection in popcorn breeding under water-limited conditions. Full article

Trehalose-6-phosphate (T6P) is involved in the regulation of plant growth and stress-related responses; however, its potential role in post-drought recovery remains unclear in legume crops. This study evaluated whether foliar application of native T6P could improve growth, yield formation, and physiological recovery in adzuki bean after pre-flowering drought stress. We aimed to propose a model for the production and drought tolerance regulation in adzuki bean. A three-year field experiment was conducted by applying T6P at both the budding stage and the initial pod stage. The plant architecture, yield, photosynthetic characteristics, defensive enzyme activity, sugar metabolism and hormone changes were evaluated. The results indicated that T6P significantly increased root, stem and leaf parameters in adzuki bean it also increased all yield traits except for the main stem branches and sections during post-drought recovery. Indeed, the yield per block of 5μM and 10μM of T6P application during post-drought recovery increased by 20.66% and 31.60% on average compared to the control under well-watered conditions and by 47.68% and 60.20% under drought stress during the three experimental years. Foliar T6P treatment was associated with higher antioxidant enzyme activities and related gene expression, lower ROS accumulation and proline content, and changes in sugar- and hormone-related traits during post-drought recovery. Therefore, foliar application of T6P at the budding and initial pod stages improved growth, yield formation, and post-drought recovery in adzuki bean. The result provide a novel strategy for T6P application for coordinating the high production potential and crop resilience. Full article

Plant communities in reservoir drawdown zones experience highly altered hydrological regimes, and responses of locally dominant species shape the biodiversity and restoration trajectories of these artificial wetlands. The water-level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR) is exposed to alternating flooding and drought, which strongly constrains both its vegetation and the biodiversity that depends on it. Cynodon dactylon dominates the herbaceous cover of the TGR WLFZ, but evidence on its stress responses remains fragmented across single-site studies. Following a PRISMA 2020 literature search and screening procedure, we synthesized 169 effect sizes from 12 qualifying experimental studies, covering biomass and morphological traits, photosynthetic gas-exchange parameters, chlorophyll content, and oxidative-stress indicators. Effect sizes were calculated as natural log response ratios (lnRR) and pooled with random-effects models; shallow and deep flooding were compared using subgroup analyses with bootstrap 95% confidence intervals. Flooding effects varied with water depth. Shallow flooding increased total biomass (+47.2%), whereas deep flooding reduced plant height (−46.5%) and root length (−22.3%). Plant height showed significant between-group heterogeneity (Q_between = 5.60, p = 0.045), indicating sensitivity to submergence depth. Flooding also increased malondialdehyde content (MDA) by 31.7%, whereas peroxidase activity (POD), superoxide dismutase activity (SOD), and photosynthetic gas-exchange parameters showed no consistent responses. Drought effects on total biomass, plant height, and total chlorophyll were non-significant, although inference was limited by a few drought-related entries. Deep flooding, therefore, appears to be a stronger constraint than drought for Cynodon dactylon in the TGR WLFZ, mainly through morphological suppression and increased oxidative damage. Given the dominant role of this species in the herbaceous layer, its depth-dependent decline is relevant both for biodiversity conservation in this artificial wetland and for elevation-based restoration planning. Full article

Film-forming antitranspirants may help potatoes tolerate moderate drought, but their effects on early tuberisation and tuber size distribution remain unclear. Two pot experiments were conducted in a polytunnel (late summer) and a glasshouse (winter–spring), with moderate drought imposed during tuber initiation and early bulking, alone (DT) or combined with an antitranspirant (di-1-p-menthene; VGDT). Leaf relative water content (RWC), stolon traits, and tuber yield and size distribution were measured. Moderate drought reduced RWC, stolon number, and tuber set, which indicates the sensitivity of early tuber development to water deficit. VGDT increased leaf RWC under drought from 55% to 71% in Experiment 1 and from 62% to 73% in Experiment 2, while the total tuber number under moderate drought increased from 5.2 to 11.7 tubers plant⁻¹ in Experiment 1 and from 6.1 to 10.7 tubers plant⁻¹ in Experiment 2. VGDT also increased the number of large (≥9 cm) tubers, shifting size distribution towards marketable classes. Although Vapor Gard improved plant water status and tuber number under drought, it did not restore performance to irrigated levels. These findings indicate its value as a complementary tool to mitigate drought-related losses during tuberisation, not a substitute for irrigation. Full article

Global climate change has intensified drought and increased nitrogen deposition, threatening forest tree seedling regeneration. To clarify how drought severity and nitrogen enrichment jointly affect seedling performance in Quercus wutaishanica, a dominant montane tree in northern China, we conducted a full two-factor pot experiment. We established three drought treatments (ambient precipitation [CK], chronic drought [CD], and intense drought [ID]), fully crossed with two nitrogen addition levels (0 and 10 g N m⁻² yr⁻¹), and measured functional traits related to growth, photosynthesis, and stress resistance. Our main results were threefold: (1) Both drought treatments significantly inhibited growth and biomass accumulation: total biomass decreased by 28% under CD and 38% under ID relative to CK, with suppression intensifying as drought severity increased. (2) Nitrogen addition increased total biomass by 12% under chronic drought, but this ameliorative effect fell to just 2% under intense drought. (3) As drought stress increased, the seedlings underwent a shift from stomatal to non-stomatal photosynthetic limitation, and from active physiological acclimation to irreversible metabolic damage. (4) Random forest modeling confirmed that biomass variation was primarily driven by traits related to water-use efficiency and resource acquisition. Overall, intensifying drought consistently constrains Q. wutaishanica seedling growth, and the beneficial effect of nitrogen addition declines sharply with increasing drought severity. These findings provide new empirical insights for predicting seedling regeneration and guiding sustainable forest nutrient management under ongoing climate change. Full article

The effects of climate change pose challenges to 21st-century society. Abiotic stresses such as salinity and drought represent a risk to biodiversity and the sustainability of urban and managed grasslands. In this study, we evaluated the interactive effects of mechanical defoliation (clipping), water deficit, and salinity under greenhouse conditions on several cultivars of two cool-season turfgrass species, Lolium perenne L. (‘Columbine’, ‘Allstarter’, ‘Esquire’) and Poa pratensis L. (‘Sombrero’, ‘Dakisha’, ‘Conni’). Water stress reduced relative leaf fresh and dry weight from approximately 66% to 28% and from 76% to 30%, respectively. Salinity induced moderate responses, mainly affecting root-related traits. Clipping reduced biomass, with relative leaf fresh and dry weight decreasing from 64% to 27% and from 86% to 28%, but it also stimulated compensatory responses, including increases in length increment from 0.17 to 0.29 cm day⁻¹, and in leaf and root water content from 63% to 67%. Lolium perenne showed greater root development than P. pratensis with higher root length (95% vs. 75%) and root surface area and volume (66% vs. 51%). Cultivar differences were evident, with ‘Columbine’ and ‘Allstarter’ showing greater stability, whereas ‘Dakisha’ was more sensitive. These findings highlight the importance of cultivar selection and clipping management under stress conditions. Full article

In transitional tropical ecosystems such as the Amazonia–Cerrado ecotone, dominant tree species experience strong environmental heterogeneity, requiring coordinated functional strategies to cope with drought, nutrient limitation, and disturbance. However, how these species integrate leaf morphoanatomical traits and wood density to persist in such environments remains poorly understood. We assessed the coordination among leaf anatomical and morphological traits and their relationship with wood density in five dominant tree species across three savanna park sites in the Amazonia–Cerrado transition. Morphological traits included leaf thickness, specific leaf area, leaf dry matter content, and wood density, alongside 17 anatomical leaf traits. We analyzed inter- and intraspecific variation and covariation patterns to identify trait-based ecological strategies along the acquisitive–conservative spectrum. We found strong coordination among traits related to protection (e.g., cuticle thickness and trichomes) and resource use, as well as clear alignment between leaf and wood traits. Species identity explained most trait variation, although leaf thickness showed notable intraspecific plasticity. Species with conservative traits exhibited thicker leaves and higher wood density, whereas species with acquisitive strategy showed higher specific leaf area and lower leaf dry matter content. Overall, trait coordination reflects integrated ecological strategies shaped by environmental heterogeneity, highlighting the role of multi-trait syndromes in driving functional adaptation in ecotonal systems. Full article

The benefits of arbuscular mycorrhizal fungi (AMF) in alleviating plant abiotic and biotic stresses have been well documented; however, how AMF modulate photosynthesis-related processes under different drought intensities is poorly understood. This study quantified the impact of different AMF formulations on the photosynthetic traits in different host plant types under different intensities of drought stress. A total of 52 published studies were included in a meta-analysis with a random-effects model. Synthesizing the research findings revealed that, under drought stress, AMF significantly improved plant photosynthetic rates and nutrient absorption, with the strongest effect on phosphorus absorption (the effect size Hedges’ g = 3.85, 95% CI: 2.76–4.95, p < 0.001). Overall, the between-study heterogeneity was moderate to high (I² = 64.7%, τ² = 0.38), indicating variability among the included studies. As drought intensity increased, the effect of AMF on the net photosynthetic rate decreased, with the transpiration rate (Tr) and stomatal conductance (Gs) first increasing and then diminishing. Drought intensity exceeding the ‘moderate’ threshold inhibited both Tr and Gs. The AMF effect on chlorophyll content differed among the plant types, with Hedges’ g being 1.656, 2.715, and 3.231 for herbaceous, grass, and woody plants, respectively. Inoculation with multiple AMF species provided greater benefits than single AMF strains in promoting chlorophyll content (Hedges’ g = 1.949 for single vs. 3.217 for mixture) and net photosynthetic rate (Hedges’ g = 2.242 for single vs. 3.986 for mixture). We conclude that the AMF–plant symbiotic association alleviates drought stress by adjusting the net photosynthetic rate, transpiration rate, and stomatal conductance. The magnitude of these responses varies depending on plant functional type, drought intensity, and AM fungal formulation. Full article

Water stress is a major abiotic constraint limiting the growth and productivity of alfalfa (Medicago sativa L.). To elucidate the adaptive mechanisms and identify key drought-tolerance genes, physiological measurements were integrated with multi-omics analyses of cultivar ‘Tamu 1’ under three water treatments: waterlogging (100% field water capacity), normal irrigation (80% FWC), and drought (light: 60% FWC, moderate: 40% FWC, severe: 20% FWC). Water stress markedly inhibited plant growth, induced oxidative stress, and reduced the photosynthetic capacity. Compared with waterlogging stress (DAMs: n = 71; DEGs: n = 313), drought stress resulted in a substantially greater number of differentially accumulated metabolites (DAMs, n = 1504) and differentially expressed genes (DEGs, n = 8006). Weighted gene co-expression network analysis (WGCNA) identified six key modules and ten hub genes associated with stress responses. Integrated transcriptomic and metabolomic analyses further revealed four major responsive pathways: starch and sucrose metabolism, phenylpropanoid and flavonoid metabolism, glutathione metabolism, and zeatin biosynthesis. Based on integrative criteria, including differential expression (|log₂FC| ≥ 1, adjusted p < 0.05), WGCNA modules significantly associated with drought-related traits (R² > 0.6), as well as functional annotation and protein–protein interaction (PPI) network topology, 28 candidate genes associated with drought tolerance were identified, of which six were further validated by quantitative real-time PCR (qRT-PCR). These findings highlight key metabolic pathways and regulatory modules underlying alfalfa responses to water stress and provide valuable candidate gene resources for improving drought tolerance. Full article

Spring drought is a major constraint in Mediterranean wheat production, where elevated temperatures and evapotranspiration after heading limit soil water availability during critical generative stages. This study investigated how post-heading drought reshapes the relationships between yield and multiple quality traits (a total of 22 variables) across ten bread wheat genotypes using multivariate analyses. Field experiments were conducted under rainfed and post-heading drought conditions over two growing seasons. The following traits were evaluated: yield components; flag leaf SPAD; physical, technological, and nutritional quality traits; flour color (L*, a*, b*); phenolic content; and antioxidant activity. Drought caused significant yield reductions, with SPAD, ear yield, grain and test weight emerging as key traits associated with yield formation. Water-limited conditions constrained yield formation in post-heading development stages while promoting certain quality improvements in wheat grain. PCA clearly separated drought and rainfed conditions: drought clustered with bioactive, pigment-related, and mineral traits, whereas rainfed conditions were associated with higher yield, protein content, gluten quality, and technological traits. These findings demonstrate that post-heading drought shifts wheat grain composition toward bioactive and nutritional constituents at the expense of yield-oriented and technological traits, emphasizing the need to select genotypes that sustain both yield stability and nutritional quality under increasing spring water limitations driven by climate change. Full article

The Tahe red deer is derived from the wild Tarim red deer, an endemic subspecies native to the Tarim Basin in Xinjiang, China. It has recently received official approval as a locally bred deer variety, developed through artificial breeding programs. This breed retains several advantageous traits from its wild ancestors, including tolerance to coarse forage, drought resistance, and a high yield of velvet antlers. To investigate the genetic mechanisms underlying velvet antler production, phenotypic data for antler weight and blood samples were collected from 73 adult Tahe red deer. Whole-genome sequencing and genome-wide association analysis were performed to identify genetic variants associated with antler weight. Population genetic analysis revealed that the observed heterozygosity (Ho) and expected heterozygosity (He) were 0.31291 and 0.32832, respectively, while the nucleotide diversity (π) was 2.17 × 10⁻³, indicating relatively high genetic diversity within the Tahe red deer population. Using a mixed linear model (MLM), a total of 189 candidate genes and 1387 significant SNP loci associated with antler weight were identified (p < 1.0 × 10⁻⁵). Gene Ontology (GO) enrichment analysis revealed that these candidate genes are primarily involved in intracellular calcium ion homeostasis, peptide and protein biosynthesis, extracellular matrix organization, the regulation of glycolysis, and cytoskeleton-related processes, including actin filaments and microfibrils. These biological functions are closely related to cell proliferation, differentiation, energy metabolism, and tissue remodeling. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis further indicated that the candidate genes are significantly enriched in several pathways, including the Notch signaling pathway, the cGMP–PKG signaling pathway, the regulation of the actin cytoskeleton, ribosome biogenesis, and mucin type O-glycan biosynthesis. These results suggest that these genes may participate in velvet antler growth and development by regulating cell proliferation and differentiation, cytoskeletal remodeling, and protein synthesis. Overall, this study identifies SNP loci and candidate genes significantly associated with antler weight in Tahe red deer, providing a theoretical basis for genetic improvement and marker-assisted selection for velvet antler production in this breed. Full article

Frequent co-occurrences of high temperature and drought in tropical regions make heat and drought tolerance of landscape plants core physiological traits that determine their landscape adaptability and community stability. However, systematic elucidation of the differentiation patterns of stress resistance between specialist and generalist tropical landscape plant species, the intrinsic correlations between heat and drought tolerance traits, and the regulatory mechanisms of leaf functional traits remains lacking. In this study, eight typical tropical landscape plant species in Xishuangbanna Tropical Botanical Garden were selected as research objects. By determining leaf chlorophyll fluorescence parameters, water relation parameters and leaf functional traits, we systematically analyzed the differences in heat and drought tolerance and interspecific differentiation characteristics between specialist and generalist species, and simultaneously elucidated the correlation patterns of drought-heat tolerance traits as well as the regulatory effects of leaf functional traits on these traits. The results showed that the turgor loss point water potential (Ψ_TLP) of generalist tropical landscape plant species was significantly higher than that of specialist species, with superior drought tolerance; in contrast, the half-lethal temperature of photosystem II (T50) of specialist species was significantly higher than that of generalist species, with stronger heat tolerance. Among the eight tested species, Bombax ceiba exhibited the strongest drought tolerance, while Baccaurea ramiflora had the optimal heat tolerance. The study also found that the drought and heat tolerance traits of tropical landscape plants exhibited stress-specific trade-offs; leaf functional traits had limited overall explanatory power for the stress resistance of tropical landscape plants and only exerted a certain regulatory effect on drought tolerance. This study clearly reveals the differences in heat and drought tolerance between specialist and generalist species. This finding not only enhances our mechanistic understanding of stress resistance in tropical plants but also provides data support for ecological restoration and conservation practices in tropical gardens. Full article

A large proportion of global peanut cultivation occurs in arid and semiarid environments, where water scarcity poses a major limitation to productivity. Climate change further intensifies this challenge by causing irregular rainfall patterns. This study aimed to investigate the physiological and yield responses of peanut genotypes under well-watered and water-stressed conditions. Seven genotypes, five drought-tolerant (C76-16, Line-8, PI 502120, AU-NPL-17 and AU16-28) and two drought-sensitive (Valencia-C and AP-3) were evaluated under two irrigation regimes across consecutive years (2024 and 2025). Seven yield-associated traits (number of pods per plant, pod length, pod width, pod yield per plant, seed weight, hundred-seed weight and pod yield per plot) along with three physiological traits (stomatal conductance, photosynthetic efficiency and leaf temperature) were measured at three growth stages. Drought stress caused a significant reduction in almost all traits, including pod yield per plot (42–44%) and hundred-seed weight (24–38%). Stomatal conductance showed the greatest reduction at all stages, especially during flowering (31–80%) and pod filling (45–74%) stages. Correlation analysis revealed that yield-related traits were negatively correlated with stomatal conductance at pod-filling under water-stress conditions. Genotypes such as PI 502120, AU-NPL-17 and C76-16 maintained higher yields with less reduction under water-stressed conditions. This study also confirmed that Line-8 employs a water-saver strategy, whereas PI 502120 uses a water-spender mechanism to cope with water stress. Additionally, findings showed that the flowering and pod-filling stages are more severely affected physiologically by drought stress, which likely contributed to the observed yield reduction. Full article

With global warming and climate change, drought stress is nowadays a threatening problem for growing vegetable crops worldwide. The introduction of more resilient and less water-demanding varieties is a key aspect for sustainable vegetable production, especially in Mediterranean countries where water availability for agricultural uses is progressively decreasing. This review highlights different mechanisms of tomato plant, as one of the most important crops of the Mediterranean countries, which are activated at physiological, biochemical and molecular levels in response to drought. With regard to the root system architecture modification, osmotic adjustments, and hormonal and antioxidant regulations are discussed. For vegetative organs, plant architecture, leaf morphology adjustments and stomatal regulation are described. Major genetic traits related to drought stress, along with responsive genes, are listed. The metabolic pathways, which determine the tolerance to drought stress, are reported and their related molecular markers used for the molecular-assisted selection (MAS) are listed. Novel growing systems and techniques which can improve efficiency for mitigating drought are highlighted; in addition, different breeding methods, both conventional and new gene-editing ones, are mentioned. Full article

Drought stress severely limits plant growth and productivity, yet the molecular basis of drought tolerance and post-drought recovery remains incompletely understood in many forage legumes. Medicago ruthenica is a perennial legume native to arid and cold regions and exhibits strong drought resilience. Results: We integrated key physiological traits related to stomatal regulation, photosynthesis, osmotic adjustment and antioxidant defense with RNA-seq across four stages (well-watered control, CK; drought for 9 days, D9; drought for 12 days, D12; and rewatering for 4 days, RW). Drought triggered stage-dependent physiological shifts, and transcriptome profiling identified >3000 drought- and rewatering-responsive genes enriched in primary metabolism, redox homeostasis and hormone signaling. WGCNA highlighted two drought-associated modules (MEcyan and MEcoral1) and prioritized three hub transcription factors for functional validation: 861 (AP2/ERF), 22 (WRKY) and 89 (bZIP). Overexpression of each gene in tobacco improved drought tolerance, as indicated by enhanced growth/root traits, increased osmolyte accumulation and antioxidant enzyme activities, and reduced membrane damage. Conclusions: Together, these results provide an integrated view of drought stress response and recovery in M. ruthenica and identify 861, 22 and 89 as candidate regulatory genes for engineering drought resilience in legumes. Full article