Comprehensive Analysis of the CDPK-SnRK Superfamily Genes in Chinese Cabbage and Exploration of Its Evolutionary Pattern in Plants

CDPK-SnRK(Calcium-dependent protein kinases -Snf1-related protein kinases) gene family plays important roles in signaling pathways for disease resistance and various stress responses as indicated by emerging evidences. In this study, we constructed comparative analyses of gene structure, retention expansion, whole-genome duplication and expression patterns of CDPK-SnRK genes in Brassica rapa and their evolution in plants. A total of 49 BrCPKs, 14BrCRKs, 3BrPPCKs, 5BrPPERKs, 56BrSnRKs were identified in B. rapa. By statistics of the number of CDPK-SnRK genes in each species, we found that the expansion of the CDPK-SnRK gene family started from angiosperm. The analysis showed PPERK was more preferentially retained than other subfamilies and CPK was similarly retained to SnRK. In addition, we identified 196 CPK genes and 252 SnRK genes in the 6 species and their different expansion and evolution types were discovered. Furthermore, the expressions of BrCDPK-SnRK genes are dynamic in different tissues as well as in response to abiotic stresses, demonstrating their important roles in development in B.rapa. In summary, this study provides genome-wide insight into evolutionary history and mechanisms of CDPK-SnRK genes following whole-genome triplication in B. rapa.