Transcription factors as molecular switches regulating plant responses to drought stress

Genome-Wide Identification and Cold Stress Response Mechanism of Barley Di19 Gene Family

The Di19 (Drought-induced 19) gene family encodes Cys2/His2-type zinc finger proteins that are known to be involved in plant responses to various abiotic stresses, including drought, salinity, and temperature extremes. However, little is known about their roles in barley (Hordeum vulgare), particularly in cold stress adaptation. This study aimed to conduct a comprehensive genome-wide analysis of the barley genome to identify Di19 gene family members and examine their expression patterns under cold stress, providing theoretical support for stress-resistant barley breeding. By aligning Di19 gene sequences from Arabidopsis and rice and using BLASTp, seven HvDi19 genes were identified in barley. Bioinformatics analysis revealed that all members contain a conserved Cys2/His2-type zinc finger domain and nuclear localization signals. Phylogenetic analysis grouped the HvDi19 genes into four subfamilies, with three homologous gene pairs, and Ka/Ks analysis indicated strong purifying selection. Tissue-specific expression analysis showed significant variation in HvDi19 expression across barley organs. Under cold stress, different barley varieties exhibited distinct HvDi19 gene expression profiles: for instance, HvDi19-1 was downregulated in cold-tolerant varieties, whereas HvDi19-7 showed increased expression in a cold-tolerant mutant, suggesting their potential roles in modulating cold response. These findings reveal the evolutionary conservation and cold-responsive expression characteristics of the HvDi19 gene family, laying a foundation for future functional studies. The results also provide important molecular resources for the genetic improvement of cold tolerance in barley, contributing to the development of stress-resilient crop varieties under climate change.

Hierarchical Regulatory Networks Reveal Conserved Drivers of Plant Drought Response at the Cell-Type Level

Drought is a critical environmental challenge affecting plant growth and productivity. Understanding the regulatory networks governing drought response at the cellular level remains an open question. Here, a comprehensive multi-omics integration framework that combines transcriptomic, proteomic, epigenetic, and network-based analyses to delineate cell-type-specific regulatory networks involved in plant drought response is presented. By analyzing nearly 30 000 multi-omics data samples across species, unique insights are revealed into conserved drought responses and cell-type-specific regulatory dynamics, leveraging novel integrative analytical workflows. Notably, CIPK23 emerges as a conserved protein kinase mediating drought tolerance through interactions with CBL4, as validated by yeast two-hybrid and BiFC assays. Experimental validation in Arabidopsis thaliana and Vitis vinifera confirms the functional conservation of CIPK23, which enhances drought resistance in overexpression lines. In addition, the authors' causal network analysis pinpoints critical regulatory drivers such as NLP7 and CIPK23, providing insights into the molecular mechanisms of drought adaptation. These findings advance understanding of plant drought tolerance and offer potential targets for improving crop resilience across diverse species.

The AP2/ERF transcription factor MhERF113-like positively regulates drought tolerance in transgenic tomato and apple

Drought is a major abiotic stress in agriculture that severely affects crop growth, yield, and quality. The APETALA2/ethylene responsive factor (AP2/ERF) plays a crucial role in maintaining plant growth, development, as well as stress tolerance. Herein, we cloned and characterized the MhERF113-like gene from Malus hupehensis. MhERF113-like is significantly induced by drought and highly expressed in leaves. Overexpression of MhERF113-like positively regulated the drought tolerance of apple calli and plants, as judged by less electrolyte leakage, lower malonaldehyde (MDA) and hydrogen peroxide (H2O2) contents in OE than those of the WT apple calli and plants under drought stress. In addition, ectopic expression of MhERF113-like gene in tomatoes improved the drought tolerance, accompanied by enhanced expression of antioxidant genes (SlAPX1 and SlSOD) and stress responsive genes (SlDREB and SlRD29), and reduced H2O2 and O2- contents in OE tomatoes. Taken together, our study demonstrated that MhERF113-like may play an important role in the regulation of plant drought tolerance, which may provide a key factor for future biotechnology applications to improve drought stress tolerance in plants.