Characterization of an uncharacterized aldo-keto reductase gene from peach and its role in abiotic stress tolerance.

The aldo-keto reductase (AKR) superfamily is a large enzyme group of NADP-dependent oxidoreductases with numerous roles in metabolism, but many members in this superfamily remain uncharacterized. Here, PpAKR1, which was cloned from the rosaceous peach tree (Prunus persica), was investigated as a member of the superfamily. While PpAKR1 had amino acids that are important in AKRs and which belonged to the AKR4 group, PpAKR1 did not seem to belong to any of the AKR4 subgroups. PpAKR1 mRNA abundance increased with abscisic acid, oxidative stress, and cold and salt stress treatments in peach. NADP-dependent polyol dehydrogenase activity was increased in Arabidopsis thaliana transformed with PpAKR1. Salt tolerance increased in Arabidopsis transformed with PpAKR1. PpAKR1, which was a previously uncharacterized member of the AKR superfamily, could be involved in the abiotic stress tolerance.