| Summary: | Cabbage (<i>Brassica oleracea</i> var. <i>capitata</i>) is a vegetable rich in glucosinolates (GSLs) that have proven health benefits. To gain insights into the synthesis of GSLs in cabbage, we systematically analyzed GSLs biosynthetic genes (GBGs) in the entire cabbage genome. In total, 193 cabbage GBGs were identified, which were homologous to 106 GBGs in <i>Arabidopsis thaliana</i>. Most GBGs in cabbage have undergone negative selection. Many homologous GBGs in cabbage and Chinese cabbage differed in expression patterns indicating the unique functions of these homologous GBGs. Spraying five exogenous hormones significantly altered expression levels of GBGs in cabbage. For example, MeJA significantly upregulated side chain extension genes <i>BoIPMILSU1-1</i> and <i>BoBCAT-3-1,</i> and the expression of core structure construction genes <i>BoCYP83A1</i> and <i>BoST5C-1</i>, while ETH significantly repressed the expression of side chain extension genes such as <i>BoIPMILSU1-1</i>, <i>BoCYP79B2-1,</i> and <i>BoMAMI-1</i>, and some transcription factors, namely <i>BoMYB28-1</i>, <i>BoMYB34-1</i>, <i>BoMYB76-1</i>, <i>BoCYP79B2-1,</i> and <i>BoMAMI-1</i>. Phylogenetically, the <i>CYP83</i> family and <i>CYP79B</i> and <i>CYP79F</i> subfamilies may only be involved in GSL synthesis in cruciferous plants. Our unprecedented identification and analysis of GBGs in cabbage at the genome-wide level lays a foundation for the regulation of GSLs synthesis through gene editing and overexpression.
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