Genome-wide identification and expression analysis of 3-ketoacyl-CoA synthase gene family in rice ( L.) under cadmium stress.

3-Ketoacyl-CoA synthase (KCS) is the key rate-limiting enzyme for the synthesis of very long-chain fatty acids (VLCFAs) in plants, which determines the carbon chain length of VLCFAs. However, a comprehensive study of KCSs in has not been reported yet. In this study, we identified 22 genes in rice, which are unevenly distributed on nine chromosomes. The gene family is divided into six subclasses. Many -acting elements related to plant growth, light, hormone, and stress response were enriched in the promoters of genes. Gene duplication played a crucial role in the expansion of the gene family and underwent a strong purifying selection. Quantitative Real-time polymerase chain reaction (qRT-PCR) results revealed that most genes are constitutively expressed. We also revealed that genes responded differently to exogenous cadmium stress in and background, and the genes with higher expression in leaves and seeds may have functions under cadmium stress. This study provides a basis for further understanding the functions of genes and the biosynthesis of VLCFA in rice.