Overexpression of Grapevine Gene Enhanced Salt Tolerance in Tobacco.

In plants, auxin/indoleacetic acid (Aux/IAA) proteins are transcriptional regulators that regulate developmental process and responses to phytohormones and stress treatments. However, the regulatory functions of the L. (grapevine) Aux/IAA transcription factor gene have not been reported. In this study, the gene was successfully cloned from grapevine. Subcellular localization analysis in onion epidermal cells indicated that VvIAA18 was localized to the nucleus. Expression analysis in yeast showed that the full length of exhibited transcriptional activation. Salt tolerance in transgenic tobacco plants and was significantly enhanced by overexpression. Real-time quantitative PCR analysis showed that overexpression of up-regulated the salt stress-responsive genes, including pyrroline-5-carboxylate synthase (), late embryogenesis abundant protein (), superoxide dismutase (), and peroxidase () genes, under salt stress. Enzymatic analyses found that the transgenic plants had higher SOD and POD activities under salt stress. Meanwhile, component analysis showed that the content of proline in transgenic plants increased significantly, while the content of hydrogen peroxide (HO) and malondialdehyde (MDA) decreased significantly. Based on the above results, the gene is related to improving the salt tolerance of transgenic tobacco plants. The gene has the potential to be applied to enhance plant tolerance to abiotic stress.