AKR2A interacts with KCS1 to improve VLCFAs contents and chilling tolerance of Arabidopsis thaliana.

Arabidopsis thalianaAKR2A plays an important role in plant responses to cold stress. However, its exact function in plant resistance to cold stress remains unclear. In the present study, we found that the contents of very long-chain fatty acids (VLCFAs) inakr2amutants were decreased, and the expression level of KCS1 was also reduced. Overexpression ofKCS1in theakr2amutants could enhance VLCFAs contents and chilling tolerance. Yeast-2-hybrid and bimolecular fluorescence complementation (BIFC) results showed that the transmembrane motif of KCS1 interacts with the PEST motif of AKR2A bothin vitroandin vivo. Overexpression ofKCS1inakr2amutants rescuedakr2amutant phenotypes, including chilling sensitivity and a decrease of VLCFAs contents. Moreover, the transgenic plants co-overexpressingAKR2AandKCS1exhibited a greater chilling tolerance than the plants overexpressingAKR2AorKCS1alone, as well as the wild-type.AKR2Aknockdown andkcs1knockout mutants showed the worst performance under chilling conditions. These results indicate that AKR2A is involved in chilling tolerance via an interaction with KCS1 to affect VLCFA biosynthesis inArabidopsis.