The Sophora AlopecuroidH+-PPase Gene SaVP1 Confers Multiple Abiotic Stress Tolerance in Arabidopsis

The physiological role of a vacuolar H+-PPase (SaVP1) from an eremophyte, Sophora alopecuroid, was evaluated through overexpressing in Arabidopsis. Overexpression of SaVP1 in Arabidopsis enhanced tolerance to drought and salt stresses and resulted in the up-regulation of several K+ and Ca2+ channel/ transporters genes, which showed a function similar to that of vacuolar H+-PPase from other plants. Moreover, the transgenic plants showed higher temperature tolerance than wild type plants, and had a higher seed yield. Overexpression of SaVP1 could improve the content of indole-3-acetic acid (IAA) in floral organs under high-temperature stress. Meanwhile, the application of IAA in low concentration led to higher fertility in the SaVP1-overexpressing plants under high temperature. These results indicate that SaVP1 might activate the auxin biosynthesis and signaling pathway in Arabidopsis to improve tolerance to heat. SaVP1 from an eremophyte could also be applied as a candidate gene for enhancing multiple stress tolerance in other plant species.