Overexpression of a mitochondrial ATP synthase small subunit gene (AtMtATP6) confers tolerance to several abiotic stresses in Saccharomyces cerevisiae and Arabidopsis thaliana.

Mitochondrial F(1)F(0)-ATPase is a key enzyme in plant metabolism, providing cells with ATP that uses the transmembrane electrochemical proton gradient to drive synthesis of ATP. A 6 kDa protein (At3g46430) has been previously purified from Arabidopsis thaliana mitochondrial F(1)F(0)-ATPase. In this study, the gene (AtMtATP6; GenBank accession no. AK117680) encoding this protein was isolated from Arabidopsis and characterized. Northern blot analyses showed that the expression of AtMtATP6 gene in Arabidopsis suspension-cultured cells was induced by several abiotic stresses from salts, drought, and cold. Over-expression of AtMtATP6 gene in transgenic yeast and Arabidopsis plants increased the resistance to salts, drought, oxidative and cold stresses. Taken together, our data raise the possibility that induction of the F(1)F(0)-ATPase plays a role in stress tolerance.