Genome-wide characterization of the rose (Rosa chinensis) WRKY family and role of RcWRKY41 in gray mold resistance
Abstract Background The WRKYs are a major family of plant transcription factors that play roles in the responses to biotic and abiotic stresses; however, a comprehensive study of the WRKY family in roses ( Rosa sp.) has not previously been performed.Results In the present study, we performed a genome-wide analysis of the WRKY genes in the rose ( Rosa chinensis ), including their phylogenetic relationships, gene structure, chromosomal locations, and collinearity. Using a phylogenetic analysis, we divided the 56 RcWRKY genes into three subgroups. The RcWRKY s were unevenly distributed across all seven rose chromosomes, and a study of their collinearity suggested that genome duplication may have played a major role in RcWRKY gene duplication. A Ka/Ks analysis indicated that they mainly underwent purifying selection. Botrytis cinerea infection induced the expression of 19 RcWRKY s, most of which had undergone gene duplication during evolution. These RcWRKY s may regulate rose resistance against B. cinerea . Based on our phylogenetic and expression analyses, RcWRKY41 was identified as a candidate regulatory gene in the response to B. cinerea infection, which was confirmed using virus-induced gene silencing.Conclusions This study provides useful information to facilitate the further study of the function of the rose WRKY gene family.