Identification of Leaf Waxy Candidate Gene and Expression Changes in Related Genes in Response to Cold Stress of Cabbage (Brassica oleracea L.)

In cabbage, epidermal wax plays a key role in adaptation to abiotic and biotic stresses. The glossy green cabbage variety, which has less wax, is becoming increasingly popular on the market. In this study, the highly inbred waxy cabbage HQ2-1 and the glossy green cabbage Y2-1 were sampled for fine mapping and transcriptomics analysis. In the glossy green leaf cabbage, inheritance follows a simple dominant pattern. BSA-seq and interval targeted sequencing technology identified <i>BoCER1</i> as the candidate gene controlling the leaf wax trait in <i>Brassica oleracea</i>. Downregulated genes in the α-linolenic acid metabolic pathway and upregulated genes in the wax synthesis pathway in HQ2-1 collectively promote wax formation in HQ2-1 leaves. Cold stress induced the upregulation of α-linolenic acid metabolic pathway genes in HQ2-1, and we speculate that the upregulation of these genes may promote jasmonic acid accumulation. Our study lays a solid foundation for further understanding the regulatory mechanism of leaf wax formation in cabbage and for the translational application of breeding new glossy cabbage varieties.