The SINAC8 gene of the halophyte Suaeda liaotungensis enhances drought and salt stress tolerance in transgenic Arabidopsis thaliana

NAC (NAM, ATAF1/2 and CUC) transcription factors play an important role in resisting abiotic stress in plants. In this study, a novel NAC gene, designated SINAC8 from Suaeda liaotungensis K. was characterized. S1NAC8 protein is localized in the nucleus, and the yeast one-hybrid screening showed that it contains an activation domain in its C-terminus and functions as a transcriptional activator. Gene expression analysis revealed that it is induced by drought and salt stress. Arabidopsis plants overexpressing SINAC8 demonstrated enhanced tolerance to drought and salt stress, showing significant advantages in seed germination, root growth, shoot growth, and survival rate compared with controls. Moreover, transgenic plants had a significantly higher proline concentration, antioxidant enzyme activity (superoxide dismutase, peroxidase, and catalase), and level of chlorophyll fluorescence than wild-type, and a significantly lower malondialdehyde concentration and electrolyte leakage under drought and salt stress. The overexpression of SWAGS in transgenic plants also enhanced the expression of stress-responsive genes such as RD20, GSTF6, COR47, RD29A, RD29B, and NYC1. In summary, S1NAC8, as a transcription factor, may change the physiological-biochemical characteristic of plants by regulating the expression of stress-responsive genes and enhance the drought and salt stress tolerance of plants. S1NAC8 can be utilized for developing drought and salinity tolerance in crop plants through genetic engineering.