The lncDR1 enhances drought tolerance in barley via the ceRNA mechanism of sponging miR4339 to induce stomatal closure.

Melatonin have been proposed as a potential alternative in enhancing drought tolerance. However, the mechanisms underlying remain poorly understood. This study tested the hypothesis that melatonin improves drought tolerance by regulating polyamine metabolism. Hydroponically grown foxtail millet (Setaria italica L.) seedlings were subjected to drought stress induced by polyethylene glycol (PEG-6000, 10%), with or without melatonin application. The results showed that exogenous melatonin improved drought tolerance by improving water uptake, increasing root hydraulic conductivity (Lpr) and whole-plant hydraulic conductance (Kplant) by 37% and 33%, respectively. Melatonin also significantly increased the activities of key enzymes involved in polyamine biosynthesis, specifically arginine decarboxylase (ADC), ornithine decarboxylase (ODC), and S-adenosyl-l-methionine decarboxylase (SAMDC), while concurrently decreasing the activities of polyamine degrading enzymes, namely polyamine oxidase (PAO) and diamine oxidase (DAO). Additionally, melatonin elevated the levels of putrescine (Put), spermidine (Spd), and spermine (Spm) in both roots and leaves. Transcriptome analysis further indicated that melatonin upregulated genes related to polyamine biosynthesis. To further verify the role of polyamines in melatonin-induced drought tolerance, seedlings were treated with exogenous Spd or a polyamine biosynthesis inhibitor (dicyclohexylammonium sulfate, DCHA) under combined drought and melatonin conditions. Exogenous Spd produced effects similar to those of melatonin under drought stress, while DCHA abolished the melatonin-induced drought tolerance and reduced its beneficial effects on root water absorption. These findings demonstrate that polyamines are involved in melatonin-induced drought tolerance in foxtail millet, supporting the positive role of melatonin in modulating drought tolerance.

Regulation of non-photochemical quenching by PsbS and zeaxanthin under variable light and drought.

ABA-cytokinin crosstalk regulate drought tolerance in Ziziphus jujuba var. spinosa through the phenylpropanoid pathway: insights from physiological and multi-omics integration.

Regulatory mechanisms of secondary metabolite biosynthesis in medicinal plants under drought: advances and perspectives.

Drought stress affects plant growth and development. Zeaxanthin, as the key substance of the xanthophyll cycle and the precursor to abscisic acid (ABA), whose synthesis depends on light, can quickly respond to drought stress and enhance plant drought tolerance. However, the molecular mechanism by which zeaxanthin adapts to drought stress is still unclear. In this study, the application of exogenous zeaxanthin via spraying was confirmed to alleviate the damage caused by drought stress in apple seedlings, and MdBCH1 and MdLCYB2, which encode proteins that catalyze zeaxanthin synthesis, enhanced drought resistance by accelerating the lutein cycle and ABA synthesis. Furthermore, a transcription factor, MdPIF4, was identified as effectively reducing the contents of zeaxanthin and ABA and negatively regulating drought resistance. Further studies confirmed that MdPIF4 inhibits zeaxanthin biosynthesis by binding to the promoters of MdBCH1 and MdLCYB2. Therefore, this study revealed the regulation of drought resistance and zeaxanthin homeostasis in apple by the MdPIF4-MdBCH1/MdLCYB2 module. These findings provide insights into the molecular mechanisms of drought resistance in plants.

Soybean productivity is significantly impacted by drought and salt stress, yet the precise molecular mechanisms responsible for abiotic stress tolerance mediated by the SUMO protease GmOTSa remain unclear. To address this gap, GmOTSa-overexpressing and CRISPR/Cas9-edited knockout soybean lines were developed to investigate its function and regulatory pathways. GmOTSa boosts drought and salt tolerance by scavenging reactive oxygen species, modulating ABA-mediated stomatal movement, and increasing the expression of stress-responsive genes. Analysis using label-free quantitative proteomics revealed an enrichment of pathways related to linoleic acid metabolism under the stress conditions. Furthermore, GmOTSa physically interacts with the 13-lipoxygenase GmLOX31, facilitating its deSUMOylation, which, in turn, stabilizes the GmLOX31 protein and enhances jasmonic acid biosynthesis. Co-overexpression of GmOTSa and GmLOX31 results in a synergistic improvement in stress tolerance. This investigation unveils a novel regulatory module involving GmOTSa and GmLOX31 deSUMOylation, connecting deSUMOylation to lipid metabolism and the adaptation of soybeans to abiotic stress.

Plants rely on gasotransmitters like hydrogen sulfide (H2S) to coordinate stress adaptation, yet how H2S orchestrates spatiotemporal responses across cell types remains unknown. Here, we generated a high-resolution single-nucleus RNA sequencing (snRNA-seq) atlas of Chinese cabbage (Brassica rapa L. ssp. pekinensis) leaves, capturing the dynamic transcriptional response to H2S over the course of 24 h. We identified 18 transcriptionally distinct clusters corresponding to nine major leaf cell types. H2S induces globally coordinated transcriptional reprogramming, prominently featuring the broad activation of defense responses across cell types. We identified two H2S-induced genes that enhance drought tolerance. BrHSP23.6, initially confined to guard cells, becomes globally expressed under H2S fumigation and is required for H2S-mediated enhancement of photosynthetic performance and drought tolerance. Similarly, BrNTF2, a de novo induced nuclear transport factor, is essential for H2S-dependent stomatal regulation and drought resilience. In parallel, H2S spatiotemporally activates hormone and sulfur metabolic pathways. Our study deciphers a spatiotemporal pattern of H2S signaling at single-cell resolution, providing a new framework for understanding how gasotransmitters orchestrate plant adaptation.

Arabidopsis MPK2 negatively regulates drought tolerance by balancing growth and stress responses.

Enhancement of very-long-chain cuticular wax biosynthesis triggered by water loss in response to pericarp senescence in litchi fruit

As climate change drives more frequent drought-heat extremes, selecting drought-tolerant trees is crucial for future forest resilience. However, the role of tree-microbial associations remains largely unclear. We investigated how geographic origin, species identity, and intrinsic water use efficiency (iWUE) shape the rhizosphere microbiome and root-rhizosphere metabolome of Quercus robur L. and Q. petraea (Matt.) Liebl. In a 6-yr common garden experiment, we analyzed trees from two distinct geographic origins (upper Rhine basin and north German lowland) using 16S/ITS metabarcoding and untargeted metabolomics. We found a consistent legacy effect of seed origin on the prokaryotic rhizosphere microbiome and metabolome, whereas tree species had no significant impact. The bacterial family Pseudonocardiaceae was enriched for trees from the drier origin (NGL), while Blastocatellaceae and Micromonosporaceae were associated with iWUE. Higher iWUE also correlated with lower prokaryotic diversity. Ellagic acid, a polyphenol associated with drought tolerance, was enriched in the drier origin. The rhizosphere fungal community, however, was largely unaffected by origin or species. Our findings suggest that ecotypic adaptation linked to origin can outweigh species-level traits in shaping the oak rhizosphere. These findings emphasize that provenance-driven adaptation influences plant-microbe interactions and underscore the need for provenance-aware selection to strengthen forest drought resilience.

From molecules to field: Integrated insights into cuticle-mediated drought tolerance in plants.

The Cladonio–Pinetum association is among Europe’s most endangered dry, sandy forest communities and is highly sensitive to microclimate and edaphic shifts. We quantified how seasonality and microhabitat (psammophilous grasslands vs. pine forests) modulate physiological traits of the dominant terricolous lichens Cladonia mitis and Cl. uncialis in Bory Tucholskie National Park (north-central Poland). From September 2022 to September 2023 we monitored six permanent sites, recording light, temperature, moisture, and soil chemistry, and seasonally measuring maximum quantum efficiency of PS II ( F V / F M ) and concentrations of usnic acid, total chlorophyll ( a + b ), lutein, and β-carotene. Usnic acid was quantified by UHPLC–PDA; chlorophylls/carotenoids by UHPLC–ESI-QqQ-MRM. F V / F M peaked in winter (0.77 ± 0.019) and reached a summer minimum (0.59 ± 0.05) in both species, consistent with photothermal and drought stress. Usnic acid showed the opposite pattern, peaking in summer (31.66 mg g⁻¹ DW) and remaining ∼2 × higher in Cl. mitis across seasons; beyond certain concentration levels, higher usnic acid content was associated with a downward trend in F V / F M . Total chlorophyll differed between species and was consistently higher in Cl. mitis ; β-carotene showed seasonal variation, whereas lutein remained stable. Multiple regression identified light, air temperature, soil moisture, pH, and nitrogen as the main predictors of both F V / F M and usnic acid, explaining > 40% of their variance. Our results demonstrate that an integrated suite of chlorophyll fluorescence, pigment profiles, and secondary metabolite levels provides a sensitive early-warning system for detecting habitat degradation in Scots pine lichen forest. Managing canopy openness and curbing nutrient enrichment emerge as key conservation levers for sustaining these communities. • Photosystem II efficiency peaks in winter, dips in summer; microclimate–driven. • Usnic acid varies by season and lichen species. • Total chlorophyll is stable; β-carotene peaks in summer stress; lutein constant. • Physiological and environmental metrics are a tool to assess Cladonio-Pinetum state.

Effectiveness of composts from decentralised composting scenarios to promote degraded soil restoration and R. officinalis drought resilience.

Plant 3D-2D-ResNet-SE: Monitoring the changes of leaf water content and chlorophyll in Betula luminifera seedlings during drought stress

Streptomyces spp. alleviates drought stress and reduces yield losses by enhancing root development, net photosynthesis, and water-use efficiency in soybean plants.

PmPPO-mediated drought adaptation mechanism in Prunus mira Koehne: Interaction with PmRad23d and regulation of ROS homeostasis.

A LEA2 domain-containing protein PpLEA37 promotes seed germination under salinity and drought stresses through abscisic acid signaling.

Drought resistance is greater in montane conifers compared to coastal conifers in northern California

Drought-induced root architectural responses in lettuce (Lactuca sativa L.): Genotype-specific mechanisms revealed by dynamic transcriptomics.