TaGF14g, a wheat 14-3-3 protein, acts as a positive regulator of drought and salt tolerance

TaGF14g enhances drought and salt tolerance by reducing ROS levels and increasing osmoprotectants content through the activation of stress-related genes and ABA signaling. Drought and high salinity severely constrain plant growth. The 14-3-3 proteins, a family of phosphopeptide-binding proteins, play pivotal roles in various signaling pathways. However, their functional mechanisms underlying drought and salt stress adaptation remain poorly understood, particularly in crop plant wheat (Triticum aestivum L.). Here, we identified a wheat 14-3-3 protein, TaGF14g, which positively modulates drought and salt tolerance. Spatiotemporal expression profiling revealed that TaGF14g is expressed in a variety of organs and tissues. Moreover, the expression of TaGF14g was significantly upregulated in response to treatments with polyethylene glycol 6000 (simulating drought), NaCl (simulating salt stress), and abscisic acid (ABA). Ectopic expression of TaGF14g exhibited improved abiotic stress resilience in transgenic tobacco (Nicotiana tabacum L.), with seedlings developing longer roots under drought and high-salinity conditions compared to control plants. Physiological analysis further showed that overexpression of TaGF14g in tobacco enhanced the activity and transcriptional levels of antioxidant enzymes, thereby improving reactive oxygen species (ROS) scavenging capacity and alleviating oxidative damage to plants. Meanwhile, TaGF14g overexpression improved drought stress tolerance by improving water retention and the accumulation of osmolytes. Under salt stress, transgenic lines showed improved tolerance through the upregulation of genes related to ion transporters. Furthermore, TaGF14b increased ABA sensitivity in transgenic tobacco and induced stress-responsive gene expression under stress conditions. Our findings demonstrate that TaGF14g confers drought and salt stress resilience by modulating physiological processes and ABA signaling pathways, thus positioning it as a promising candidate for developing stress-resistant crop varieties.