Cloning Of Promoter And CDNA For StNPR2 In Potato And Construction Of The Expression Vector

Potato(Solamum tuberosum L) is one of the main food and economic crops. Its yield and quality are severely restricted by various diseases. NPR1(non-expressor of pathogenesis-related gene 1) is a key regulator of plant disease resistance involved in Salicylate (SA) signal pathway. NPR1 can induces expression of PR gene (pathogenesis related gene) and produces systemic acquired resistance (SAR) to confer resistance to plants. In this study, we focused on the homologous gene of NPR1, StNPR2. From bioinformatic software analysis, it showed that there are four kinds of predicted transcriptional factors binding sites in the promoter of StNPR2, which are MYB, WRKY, bZIP (Basic leucine zipper) and homeodomain protein binding sites. StNPR2 protein has three conserved domains of NPR1 protein which are ankyrin repeat sequences, BTB/POZ domain and NPR1-like C domain. StNPR2 shares high identites with StNPRl(56%), AtNPR4(51%) and AtNPR3(51%). Phylogenetic analysis showed that StNPR2 and StNPR1 are both belong to the branch of AtNPR3 and AtNPR4. We also found that BTH can induce the expression of StNPR2. The expression level at 4hr post BTH treatment was the highest, then it gradually decreased. We have successfully cloned the promoter and cDNA sequence of StNPR2 and constructed the StNPR2 binary vector, driven by its own promoter. Our study will lay foundation for further research of the roles of StNPR2 in potato defense responses.