Cloning and Expression of Pathogenesis-related Protein Gene, BoPR1, in Brassica oleracea var. italica

Pathogenesis-related proteins (PRs) are crucial in the induced systemic disease resistance for plants. Using real-time fluorescence quantitative PCR, this study isolated a gene, designated as BoPR1, frombroccoli to examine its expression patterns after inoculated by pathogens, Plasmodiophora brassicae and Sclerotinia sclerotiorum. A sequence analysis indicated that the full genome DNA of BoPR1 was 489 bp in length encoding 162 amino acids and containing no intron. The deduced protein consisted of a signal peptide and a SCP domain. The results from aphylogenetic analysis showed thatBoPR1 had a minimum genetic distance, clustering on a same clade, with the PR1 proteins from Brassica napus and B. rapa, indicating a close relationship among them. On the other hand, it was remotely related to Tarenaya hassleriana, as the genetic distance between the two PR1swas the greatest among the tested samples. Theq RT-PCR results suggested that the expression of BoPR1 was induced by P. brassicae, with the highest level observed 5 d after inoculationwhich was 11.84-fold of control. But, BoPR1 expression was not affected by S. sclerotiorum. Theobtained isolation and expression information on BoPR1 would be useful for futureresearch on thedisease resistance mechanism as well as the molecular breeding programs on B. oleracea.