Gas Chromatography-Mass Spectrometry Metabolite Analysis Combined with Transcriptomics Reveals Genes Involved in Wax Biosynthesis in L.

Cuticular waxes are essential for protecting plants from various environmental stresses. serves as an excellent model for investigating the regulatory mechanisms underlying cuticular wax synthesis with notable epidermal wax characteristics. A combination of gas chromatography-mass spectrometry (GC-MS) metabolite analysis and transcriptomics was used to investigate variations in metabolites and gene expression patterns between the wild type (WT) and glossy mutant type () of . The WT surface had a large number of acicular and lamellar waxy crystals, whereas the leaf surface of was essentially devoid of waxy crystals. And the results revealed a significant decrease in the content of 16-hentriacontanone, the principal component of cuticular wax, in the mutant. Transcriptomic analysis revealed 3084 differentially expressed genes (DEGs) between WT and . Moreover, we identified 12 genes related to fatty acid or wax synthesis. Among these, 10 DEGs were associated with positive regulation of wax synthesis, whereas 2 genes exhibited negative regulatory functions. Furthermore, two of these genes were identified as key regulators through weighted gene co-expression network analysis. Notably, the promoter region of () exhibited a 258-bp insertion upstream of the coding region in and decreased the transcription of the gene. This study provided insights into the molecular mechanisms governing cuticular wax synthesis in , laying the foundation for future breeding strategies.