Potato transformation with the HvNHX3 gene and the improvement of transformant salt tolerance

Transformation by genes of various ion transporters is a tool to study plant salt tolerance mechanisms. In this work, the gene of a vacuolar NHX antiporter HvNHX3 was introduced in two potato Solanum tuberosum L. cultivars, Yubiley Zhukova and Skoroplodny-7. The binary vector pCambia-HvNHX3 was made and used for transformation. This vector carries HvNHX3 and NPTII for kanamycin selection each driven by 35S promoter from cauliflower mosaic virus. The presence of the target gene HvNHX3 and its mRNA were confirmed in 35 out of 48 kanamycin-resistant transformants. The growth parameters of 13 transgenic lines were measured in control and NaCl-containing media. The transformation of a relatively salt-tolerant cv. Yubiley Zhukova did not significantly change its growth characteristics and salt tolerance. In control conditions, most transgenic lines of cv. Skoroplodny-7 had the larger biomass and height. Unlike untransformed plants, they rooted and grew on 100 mM NaCl, indicating their greater salt tolerance.