With the changing climatic conditions, drought has become one of the most threatening abiotic stress factors that adversely affect rice cultivation and productivity. Although the involvement of the jacalin domain-containing protein, OsSalT, has been reported in drought and salinity tolerance, its functional mechanism still remains largely unexplored. In this study, expression of the OsSalT gene was found to be positively correlated with the drought tolerance potential with its higher transcript abundance in the tolerant indica rice cultivar, Vandana, and lower abundance in the susceptible cultivar, MTU1010. Moreover, the overexpression of OsSalT gene in rice and its ectopic expression in tobacco significantly improved drought stress tolerance in the transgenic lines. The transgenic lines exhibited significantly improved growth and higher osmolyte accumulation over the wild-type (WT) plants under drought stress. Fascinatingly, the yeast two-hybrid and bimolecular fluorescence complementation (BiFC) analyses confirmed the interaction of OsSalT protein with two interesting transcription factors (TFs), OsNAC1 and OsDREB2A. In silico analysis followed by yeast two-hybrid assay further revealed that the OsSalT protein interacted with the C-terminal domains of both OsDREB2A and OsNAC1 leading to their activation. This triggered the induction of their downstream drought-responsive genes. Together, this study unravelled a novel model for OsSalT-mediated regulation of drought tolerance in plants.

随着气候条件的变化，干旱已成为最严重的非生物胁迫因素之一，对水稻的种植和生产力产生不利影响。尽管已经报道了含jacalin结构域的蛋白质Os SalT参与干旱和盐分耐受性，但其功能机制仍在很大程度上尚待探索。在这项研究中，表达OsSalT发现基因与它较高的转录物丰在宽容的耐旱性潜力正相关籼水稻品种，范达娜和低丰度感病品种，MTU1010。而且，OsSalT的过表达水稻中的水稻基因及其在烟草中的异位表达显着提高了转基因品系的耐旱性。转基因品系在干旱胁迫下比野生型（WT）植物表现出显着改善的生长和更高的渗透压积累。令人着迷的是，酵母双杂交和双分子荧光互补（BiFC）分析证实了Os SalT蛋白与两个有趣的转录因子（TF）Os NAC1和OsDREB2A的相互作用。通过计算机分析，然后进行酵母双杂交检测，进一步揭示了Os SalT蛋白与Os DREB2A和Os的C末端结构域相互作用NAC1导致其激活。这触发了其下游干旱反应基因的诱导。总之，这项研究揭示了一种新的Os SalT介导的植物抗旱性调控模型。