Ascorbate peroxidase gene from Brassica napus enhances salt and drought tolerances in <i>Arabidopsis thaliana</i>

Abstract

A full-length cDNA clone, BnAPX (GenBank: FJ965556.1) encoding ascorbate peroxidase and isolated from Brassica napus, was successfully introduced into Arabidopsis thaliana. Investigation into the function of BnAPX demonstrated that BnAPX transgenic plants grew better than wild type under NaCl stress, and also had higher germination rate and longer root length. Moreover, under the drought stress, BnAPX transgenic seeds displayed higher germination rate and the seedlings showed reduced wither and apoptosis phenomena. Therefore, our studies revealed that BnAPX was able to enhance the environmental tolerance of Arabidopsis to salt and drought stresses. In addition, transgenic Arabidopsis had lower H₂O₂ content because of the insertion and the overexpression of BnAPX. So, the mechanism of the tolerances in transgenic lines can be explained by reduction of H₂O₂ injury.

Key words: Ascorbate peroxidase, Arabidopsis thaliana, salt tolerance, drought tolerance.