[Aluminum-resistance of AHA1 transgenic Arabidopsis thaliana: physiological analysis]

As one of the major genes encoding plasma membrane H+ -ATPase, AHA1 gene plays an important role in regulating plant development and resistance to adverse stress. Taking AHA1 transgenic and wild type Arabidopsis thaliana as test plants, the nutrient uptake, resistance to oxidative stress, and organic acid secretion of the plants under aluminum (Al) stress were examined. The results showed that Al decreased the uptake of nitrogen (N), potassium (K), calcium (Ca) and magnesium (Mg), but increased the phosphorus (P) uptake by A. thaliana roots. AHA1 transgenic plant could accumulate more P and less Al than wild type plant. Al stress induced the increase of plant SOD and POD activities, but no significant difference was observed between AHA1 transgenic and wild type A. thaliana. Al triggered the secretion of organic acids significantly, and AHA1 transgenic plant secreted more organic acids than wild type plant. Vanadate, an inhibitor of plasma membrane H+ -ATPase, could inhibit the secretion of organic acids significantly, while Zn2+ and Mg2+ could promote the Al-induced secretion, and partially improve the inhibitory effects triggered by vanadate. It was suggested that AHA1 transgenic A. thaliana could increase its Al resistance via enhanced P uptake and organic acid secretion.