Molecular characterization of StNAC2 in potato and its overexpression confers drought and salt tolerance

Potato is one of the most important food crops in the world. Many plant transcription factors (TFs) have been demonstrated to be essential for improvement of plant stress tolerance traits. However, very few TFs were used for improving potato stress tolerance. In this study, we presented the characterization of a new potato StNAC2 gene. The StNAC2 protein contains five subdomains of NAC proteins and belongs to NAP subfamily. StNAC2 is constitutively expressed in potato leaves, stems, tubers, flowers and roots. Transcripts of StNAC2 were significantly induced by Phytophthora infestans, the causal agent pathogen of potato late blight. StNAC2 also could be induced by wounding, salt, drought as well as signal molecules such as salicylic acid and abscisic acid, suggesting that StNAC2 transcription factor involved in the signal transduction cascades in responses to abiotic and biotic stresses in potato. Overexpression of StNAC2 in transgenic potato significantly enhanced salt tolerance in vitro and drought tolerance in pot growing condition. Thus, the functional analysis of the new StNAC2 gene in this study will enrich knowledge for understanding the function of the NAC genes in potato stress tolerance.