Understanding the promotion of heat treatment on the flavor of Lentinula edodes using metabolomics integrated with transcriptomics.

The transcriptome and metabolome analyses revealed the differentially expressed metabolites (DEMs) and genes (DEGs) in the dried Lentinula edodes' response to heat treatment. Most DEMs between the L.edodes sample groups were lipids and lipid-like molecules, nucleosides, nucleotides, analogs, and organic acids and derivatives. DEMs enrich the pathway of the TCA cycle, alanine, aspartate, glutamate metabolism, and arginine biosynthesis. The proportion of DEGs annotation in the metabolism pathway and the number of DEGs increased within the drying process of 2 h. The DEGs were annotated in the signal transduction and amino acid metabolism pathways during the drying process of 2 h ∼ 3 h. Five DEGs including LE01Gene04306, LE01Gene06275, LE01Gene11513, LE01Gene13848 and LE01Gene13853 existed in all comparative groups. Twenty-nine DEMs marker can be used for monitoring the quality of L.edodes during drying. The metabolic pathways, secondary metabolites biosynthesis, and unsaturated fatty acid biosynthesis were the landmark pathways that monitor DEMs and DEGs, and gamma-linolenic acid was a signal DEM marker. It provides new insights for understanding the flavor formation of L.edodes during the hot-air drying process.