Functional analysis of open stomata 1-slow anion channel associated 1-6 protein module in enhancing drought tolerance in tomato through stomatal regulation mechanisms

Tomato (Solanum lycopersicum) is an important vegetable crop, whose growth and development are frequently subjected to drought stress, which severely limits its growth and yield. Identifying key drought-resistance genes in tomato is crucial for elucidating the mechanisms of drought resistance and improving tomato's drought tolerance, which has practical implications for agricultural production. The results of this study demonstrate that silencing SlSLAC1-6 (Slow anion channel associated 1-6) reduces tomato's drought tolerance. SnRK2.6/OST1 (Open stomata 1) protein kinase is a key component in plants' resistance to abiotic stress. Interactions between SlOST1 and SlSLAC1-6 were confirmed through Y2H, BiFC, LCI, Co-IP, and Pull-down assays. Simultaneously, overexpression and knockout of SlOST1 proved that it positively regulates tomato's drought tolerance by influencing Reactive Oxygen Species (ROS) homeostasis, photosynthetic capacity, stomatal closure, and Other mechanisms. Silencing SlSLAC1-6 in SlOST1 knockout Plants further reduced tomato's drought tolerance. The regulation of tomato drought tolerance by SlOST1 and SlSLAC1-6 highlights the complexity of plant adaptation to drought. These findings provide new insights into the regulatory network of the SlOST1-SlSLAC1 protein module in tomato drought tolerance and offer gene resources for future tomato drought-resistance breeding.

Drought stress; SlOST1; SlSLAC1–6; Stomata; Tomato.