Genome-Wide Characterization and Analysis of CIPK Gene Family in Two Cultivated Allopolyploid Cotton Species: Sequence Variation Association with Seed Oil Content and the Role of GhCIPK6

摘要

Calcineurin B-like protein-interacting protein kinases ( ), as key regulators, play an important role in plant growth and development and the response to various stresses. In the present study, we identified 80 and 78 genes in the and , respectively. The phylogenetic and gene structure analysis divided the cotton genes into five groups which were classified into an exon-rich clade and an exon-poor clade. A synteny analysis showed that segmental duplication contributed to the expansion of gene family, and purifying selection played a major role in the evolution of the gene family in cotton. Analyses of expression profiles showed that genes had temporal and spatial specificity and could be induced by various abiotic stresses. Fourteen genes were found to contain 17 non-synonymous single nucleotide polymorphisms (SNPs) and co-localized with oil or protein content quantitative trait loci (QTLs). Additionally, five SNPs from four were found to be significantly associated with oil content in one of the three field tests. Although most genes were not associated with natural variations in cotton oil content, the overexpression of the gene reduced the oil content and increased C18:1 and C18:1+C18:1d6 in transgenic cotton as compared to wild-type plants. In addition, we predicted the potential molecular regulatory mechanisms of the genes. In brief, these results enhance our understanding of the roles of genes in oil synthesis and stress responses.