Genome-wide identification and characterization of pathogenesis related protein 1 gene family in Brassica juncea

Pathogenesis related protein 1 (PR1) family are key players of plant defence response against pathogens, however, their role in Brassica juncea is not fully understood. Here, we performed genome wide identification and characterization of PR1 gene family in B. juncea. A total of 43 members of BjuPR1 gene family were identified in mustard genome, designated as BjuPR1-1 to BjuPR1-43. Based on phylogenetic analysis, Bju-PR1 proteins were grouped into five primary clusters (I-V) according to their conserved motifs and gene structures. The BjuPR1 genes consist of 1 to 5 coding exons, and a total of 10 conserved motifs have been identified, with motif 2 appearing in nearly all PR1 proteins. Domain analysis revealed that CAP domain is highly conserved across BjuPR1 proteins along with caveolin-binding motif (CMD), and CAPE cleavage motif. Chromosomal mapping showed that 43 BjuPR1 genes were distributed on 13 of the 18 mustard chromosomes. Promoter analysis of BjuPR1 gene family showed multiple growth, hormone-responsive, biotic and abiotic stress-responsive elements. Expression analysis showed distinct expression pattern of BjuPR1 after biotic, abiotic and hormonal treatments. This study provides comprehensive information on PR1 gene family in B. juncea which can be further used for their functional validation.