Genome-wide identification, transcript profiling and functional analyses of PCP gene family in Wucai (Brassica campestris)

Abstract Pollen coat proteins (PCPs) are cysteine-rich small-molecule proteins, which exhibit high levels of polymorphism and are expressed in gametocytes. Previous investigations have revealed that PCP genes are involved in pollen wall synthesis, pollen-stigma recognition, pollen development and germination. However, gene expression and function of PCP family in pollen development is not well understood in Wucai ( Brassica campestris L.). In this study, genome-wide identification and expression analysis of the BcPCP gene family members were conducted, including their physical and chemical properties, chromosome localization, phylogenetic tree, gene structure, and tertiary structure. A total of 20 BcPCP genes were identified and classified into three subfamilies with high homology to Arabidopsis thaliana. Furthermore, PCP members associated with male sterility were screened based on several transcriptome and proteome datasets, and BraA02g002400.3C was identified as a candidate gene. Gene sequence analysis revealed that this gene was homologous to GRP20 gene, and was named BcGRP20 . Functional analysis of this gene showed that overexpression of BcGRP20 gene in the Arabidopsis grp20 mutant could restore anther fertility.