Over-expression of ZmPti1, a homologue to Pti1, increases salt tolerance of Arabidopsis thaliana

Studies have shown that Pti1 plays an important role in plant disease resistance pathway. However, Pti1 have not been studied for its roles under salt stress condition. Previous study has shown that maize ZmPti1 is induced by salicylic acid (SA), low-temperature, mannitol and salt. In order to analyze the further biological functions of ZmPti1, ZmPti1 was over-expressed in Arabidopsis. Under salt stress, compared to wild type, transgenic plants grew better, had higher seedling fresh and dry weight (FW, DW), seed yields and the superoxide dismutase (SOD) activity; Seedling FW and DW of S1-1, S2-1 transgenic plants increased significantly than that of WT; Seed weight of S1-1, S2-1 transgenic plants increased 71 and 106% respectively; However malondialdehyde (MDA) content and relative electric conductivity (ion leakage) of transgenic plants were kept to a relative lower level. Based on the present knowledge, this is the first report that showed that the over-expression of Pti1-like gene enhances the salt resistance in plants.