Overexpression of improves the tolerance of Arabidopsis to salt stress.

Alternative oxidase (AOX) has a well-established involvement in plant growth and stress tolerance in many studies. In this study, we isolated and characterized the AOX2 from . The Open Reading Frame (ORF) contains 1029 nucleotides and encodes 342 amino acid residues. The inferred amino acid sequence of shared the highest sequence similarity with a homolog from . The transcripts were relatively abundant in the old leaves and significantly up-regulated by salt stress. Subcellular localization analysis showed that was located in the mitochondria. We transformed into wild-type and found that compared with wild-type and mutant lines, heterotopic expression of increased proline content, and peroxidase and superoxide dismutase activities, while decreasing relative conductivity and the reactive oxygen species level. Further, the ratio of alternate respiration to the total respiration in plants that overexpressed was significantly higher than that in wild-type and mutant plants under salt stress. These results indicate that plays a key role in salt tolerance.