Morphophysiological hormonal and molecular mechanisms of rice adaptation to drought and salinity stress

Molecular and physiological mechanisms of drought tolerance in grapevine

This review synthesizes recent advances in elucidating the molecular and physiological mechanisms underlying drought tolerance in Vitis vinifera to provide an integrative conceptual framework to support sustainable viticulture in water-limited environments.

Physiological and transcriptomic responses of Ginkgo biloba to salt stress and exogenous melatonin

Introduction Soil salinization constrains plant growth, and enhancing salt tolerance is of great significance. Methods Here, Ginkgo biloba seedlings were treated with control (CK), salt stress (S), or salt stress + melatonin (S+M). Integrating physiology, transcriptomics, and weighted gene co-expression network analysis (WGCNA), we explored how melatonin enhances salt tolerance. Results and Discussion Salt stress reduced chlorophyll content, suggesting potential impairment of photosynthetic capacity, appeared to increase membrane lipid peroxidation, and led to substantial proline accumulation. Melatonin treatment appeared to up-regulate the MAPK gene MYC2 and down-regulate PP2C and RbohD, suggesting a potential alleviation of oxidative stress. WGCNA identified MEblue (MAPK-enriched) positively correlated with salt stress and proline, and MEgreen (photosynthesis-enriched) positively correlated with chlorophyll and catalase (CAT) activity but negatively correlated with salt stress. Melatonin appeared to help restore MEgreen expression, potentially reducing oxidative damage and appearing to help stabilize chlorophyll. Melatonin also appeared to help maintain photosystem II (PSII) genes (Lhcb1, Lhcb4) and reduced flavonoid accumulation. These findings provide insights into the model of melatonin-mediated salt stress responses in gymnosperms. This work may support salt-tolerant Ginkgo biloba breeding and the application of melatonin in forestry.

Drought responses in rice (Oryza sativa L.): An integrated review of morphological, physiological, biochemical, phenological and genetic perspectives

Rice (Oryza sativa L.) production is severely affected by drought, which reduces yield, growth and physiological functions in various environments. This review integrates the morphological, physiological, biochemical, phenological and genetic responses of rice to drought, focusing on both common and environment-specific responses. Rice plants respond to water deficit by reducing leaf area and stomatal opening and modifying osmotic potential; roots may deepen or alter their architecture and flowering time may be delayed as an escape mechanism. Biochemically, osmolytes, antioxidants and hormones, especially abscisic acid (ABA), are key players in stress tolerance. Genetic mapping has identified several quantitative trait loci (QTLs) and candidate genes associated with root architecture, osmotic adjustment and flowering time, while transcriptomic studies have revealed the regulatory mechanisms underlying these traits under drought conditions. However, several challenges remain, including the lack of root phenotyping under field conditions, the instability of QTL effects across environments and the limited translation of pot-based findings to field performance. Integrated approaches that involve high-throughput field phenotyping, multi-environment trials to assess genotype × environment interactions and better integration of genomics with physiological traits across a variety of genetic backgrounds will be essential for future advances. These integrated approaches are pivotal in bridging the gap between field performance and the underlying physiological and molecular mechanisms, thereby facilitating the development of drought-resilient rice cultivars.

Oxidative Stress and Tissue-Specific Physiological Responses Induced by Salinity in Oenothera biennis Seedlings

Sugarcane under siege: integrated physiological, molecular responses and mitigation strategies to salinity and drought stress

Saline soil and drought are among the most devastating abiotic stresses constraining sugarcane (Saccharum spp.) production globally, with soil salinity affecting over 1,125 Mha worldwide and drought causing severe yield losses in tropical and subtropical agroecosystems. As a glycophytic C4 crop supplying ~80% of the world’s sugar, sugarcane is particularly vulnerable, with threshold salinity tolerance at a mere 1.7 dS m–1 electrical conductivity (EC). This review integrates recent developments in the physiological, biochemical, and molecular responses of sugarcane during stress conditions. Under salinity, photosynthetic CO2 efficiency, chlorophyll integrity, source–sink partitioning, reactive oxygen species (ROS) metabolism, phytohormone signaling, and osmolyte accumulation are altered based on the sugarcane cultivars and cultivation regions. Under drought, stomatal regulation, root hydraulics, abscisic acid (ABA) cascades, and the expression of dehydrin and late embryogenesis abundant (LEA) proteins govern tolerance. At the molecular level, ion-transporter genes (SOS pathway), DREB/ERF transcription factors, aquaporins, and small RNAs constitute central regulatory hubs. Mitigation strategies, including agronomic interventions, exogenous osmoprotectants, plant growth-promoting rhizobacteria, biochar amendment, and advanced breeding tools such as CRISPR/Cas9, marker-assisted selection, and transgenic approaches, are comprehensively discussed for sustainable sugarcane production.

ZmGRXCC13, a key factor in coping with drought and saline-alkali stress.

Maize (Zea mays L.) is a paramount global staple crop; however, its production is severely limited by diverse abiotic stresses, particularly drought and saline-alkali stress. Although glutaredoxins (GRXs) are known to regulate plant growth and stress responses, their specific functions and underlying molecular mechanisms in maize under drought and saline-alkali conditions remain largely elusive. In this study, we cloned the maize GRX family member ZmGRXCC13 (Zm00001d037757) and characterized its biological functions in abiotic stress tolerance. Quantitative real-time PCR (qRT-PCR) analyses revealed that ZmGRXCC13 is predominantly expressed in maize leaves, and its expression is significantly up-regulated by drought, saline-alkali, and abscisic acid (ABA) treatments. Heterologous expression of ZmGRXCC13 in Escherichia coli (BL21) and yeast cells enhanced their cellular viability under drought and saline-alkali stresses. Subcellular localization assays indicated that the ZmGRXCC13 protein is localized to both the nucleus and the cytoplasm. Furthermore, transgenic Arabidopsis plants overexpressing ZmGRXCC13 exhibited significantly enhanced tolerance to drought and saline-alkali stresses compared with wild-type plants. This robust tolerance was attributed to elevated antioxidant enzyme activities and an enhanced capacity for scavenging reactive oxygen species (ROS), which effectively mitigated stress-induced cellular damage. In addition, yeast two-hybrid (Y2H) and luciferase complementation assay (LCA) confirmed that ZmGRXCC13 physically interacts with Zmrnrl2. Taken together, our results demonstrate that ZmGRXCC13 acts as a positive regulator in plant responses to drought and saline-alkali stresses. These findings provide a solid theoretical foundation for further unraveling the molecular mechanisms underlying abiotic stress tolerance in maize.