The Essential Role of W5 in Wax Metabolism in Wheat ( Triticum aestivum L.)

Epicuticular wax serves as an interface with the environment and thus plays an important role in the resistance to various biotic and abiotic stresses. Previously, we identified the wax-deficient mutant w5 , and GC–MS profiling showed that β-diketone biosynthesis was completely blocked and the content of some other components also decreased significantly in the w5 mutant. In the present study, comparative transcriptome profile of the flag-leaf sheath between the w5 mutant and its wild type was performed, and the expression patterns of differentially expressed genes in wax metabolism pathway were analyzed. The results showed that a total of 767 differentially expressed genes were identified and they were mainly enriched in wax biosynthesis and transportation pathways by Gene Ontology (GO) analyses. Further analysis showed that the expressions of epicuticular wax metabolism-related genes were almost significantly downregulated, which might contribute to the dramatic decrease of the epicuticular wax content in the w5 mutant. Here, our study delineated a transcriptional landscape of the wax metabolism regulatory genes in the w5 mutant and paved a way for further exploring the molecular mechanisms of epicuticular wax metabolism in wheat.