Cloning and Expression Analysis of a Pathogenesis-related Protein 10 Gene from Juglans sigillata

The activation and accumulation of pathogenesis-related protein(PR)10 play predominant roles in the defense response against pathogens. Based on a Juglans sigillata expressed sequence tag (EST) encoding PR10, gene-specific primers were designed and used to amplify the full-length cDNA of a novel PR10 gene by rapid amplification of cDNA ends (RACE). This gene was named as JsPR10-1. JsPR10-1 was 776 bp in length with an open reading frame (ORF) of 483 bp, a 5'-untranslated region (UTR) of 74 bp, and a 3'-UTR of 219 bp, and the ORF encoded a protein with 160 amino acid residues. There was an intron of 124 bp in the genomic sequence of JsPR10-1. Homology analysis indicated that JsPR10-1 was homologous with PR10s from Quercus suber,Fagus sylvatica and Castanea sativa; moreover, JsPR10-1 clustered together with the PR10s from dicots in the phylogenetic tree. qRT-PCR analysis showed that the expression levels of JsPR10-1 were induced by four different plant signaling molecules, including salicylic acid, jasmonic acid, ethylene, and H₂O₂. In addition, after inoculation with Colletotrichum gloeosporioides, JsPR10-1 was sharply up-regulated with the highest expression level at 8 h. The JsPR10-1 gene was involved in the defense response against C. gloeosporioides. This experiment lays a theoretical foundation for revealing the mechanism of resistance in J. sigillata.