Abstract:In this study, utilizing the salt tolerant gene E3 ubiquitin ligase HERC2 sequence in sunflower which acquired previously, we constructed the transient expression vector Cam35SHERC2GFP. Subcellular localization was carried out by transforming onion epidermal cells with particle bombardment. The expression analysis, that of root, hypocotyl and leaf between the salttolerant hybrid P50 and the saltsensitive hybrid P29 under 120 mmol·L-1 NaCl stress, was done by RTqPCR. Plant expression vector pPZP221HERC2 was constructed. HERC2 was transferred into tobacco to verify salttolerant functionality by Agrobacteriummediated. The results showed that: (1) subcellular localization showed that HERC2 protein expressed in cell membrane, cytoplasm and nucleus; (2) the expression of HERC2 gene was upregulated between the salttolerant hybrid P50 and saltsensitive hybrid P29 under NaCl stress, but the expression quantity of the former is higher than that of the latter; (3) the salt tolerance of transgenic HERC2 tobacco was stronger than that of the wild type tobacco. The study laid a foundation for analyzing of salt tolerance mechanism in sunflower and breeding salttolerant cultivar.