NAC transcription factors play an important role in the regulation of plant growth, development, and responses to salt stress. The gene SiNAC77 in Sesamum indicum L. is involved in the response process to salt stress. Here, SiNAC77 was cloned to investigate its salt-tolerant function stress, which may provide a theoretical reference and valuable gene resource for breeding salt-tolerant sesame（Sesamum indicum L.）plants. First, the coding sequence（CDS）of SiNAC77 was cloned from Luzhi No.1, and its gene sequence and amino acid sequence characteristics were analyzed using bioinformatics tools. Subsequently, an SiNAC77-overexpressed vector was constructed and transformed containing SiNAC77 was constructed and the transformation of Arabidopsis was conducted using Agrobacterium tumefaciens. Finally, the salt-tolerant genotypes, physiological and biochemical indexes of the transgenic plants were analyzed under saline stress. As results, the CDS region of SiNAC77, 1 008 bp in length, was cloned successfully. The SiNAC77 gene encoded a protein containing 335 amino acids, with a molecular weight of 135.93 kD, an isoelectric point of 4.91 and 33 potential phosphorylation sites. The SiNAC77 promoter contained MBS, STRE, ARE, ABRE and TCA elements, functionally known to be involved in abiotic stress and phytohormone responses. The SiNAC77 overexpression vector was constructed and transformed successfully into Arabidopsis, and 12 independent transgenic lines were generated. Compared with wild-type Arabidopsis under salt stress, the transgenic lines had significantly higher seed germination rates, longer primary roots, higher fresh weights, significantly lower Na+/K+ ratios and MDA contents and higher SOD and POD antioxidant enzyme activities. In summary, the overexpression of SiNAC77 improved the salt tolerance in transgenic plants by enhancing the activities of antioxidant enzymes and reducing ionic toxicity and oxidative damage.
