Expression and functional analysis of a PR-1 Gene, MuPR1, involved in disease resistance response in mulberry (Morus multicaulis)

In the present study, the cDNA (designated MuPR1) of PR1 gene was obtained from mulberry. Our results showed that MuPR1 shares some conserved characteristics with its homologues from different plant families. MuPR1 was localized exclusively to the extracellular spaces, and the MuPR1 gene was expressed constitutively in all selected mulberry tissues, although its expression levels varied substantially. It was also showed that MuPR1 expression was induced by pathogen, MeJA, SA and GA(3), and transgenic Arabidopsis overexpressing MuPR1 showed enhanced resistance to Botrytis cinerea and Pst. DC3000. Moreover, the peptide derived from MuPR1 protein C-terminus with a PxGNxxxxxPY motif was suggested to play a role in activating plant resistance. Furthermore, the MuPR1 gene may have roles in mediating the rates of oxygen radical formation and detoxification. Therefore, the MuPR1 gene may be a candidate gene for breeding resistant mulberry varieties in the future.