Integrated transcriptomic-metabolomic analysis of wax biosynthesis in castor bean (Ricinus communis L.)

This study investigated the molecular regulatory mechanisms and metabolic pathways underlying wax biosynthesis in castor bean (Ricinus communis L.), with a focus on wax-deficient mutants. We performed metabolomic and transcriptomic analyses of the wax-deficient mutant SH8 and its wild type SHA1. Transcriptome profiling identified 610 differentially expressed genes (DEGs) between SH8 and SHA1, including 303 upregulated and 307 downregulated genes. Functional annotation and KEGG enrichment of these DEGs highlighted 12 genes associated with fatty acid synthesis and transport related to wax formation, spanning pathways such as fatty acid degradation, fatty acid elongation, cutin/suberine/wax biosynthesis, and biosynthesis of unsaturated fatty acids. In addition, correlation analysis between DEGs and differential metabolites identified several key genes involved in wax synthesis and metabolism, including CER1, KCS10, LACS1, CYP86A8, and FAR3-like. These results provide a basis for elucidating wax biosynthesis in the castor bean epidermis and support the identification and cloning of key wax-related genes, facilitating the development of castor bean varieties with improved stress tolerance.