Investigating the Genetic and Molecular Basis of Melanin and Edible Quality in Auricularia cornea.

For the first time, a regulatory network linking melanin, genes, pathways, and edible quality was constructed for 138 Auricularia cornea strains sourced domestically and internationally. This marks the inaugural study of A. cornea spanning from cellular to physical-mechanical properties. Correlation analysis between melanin and edible quality traits (hardness, springiness, cohesiveness, gumminess, chewiness, and resilience) revealed that hardness, cohesiveness, and gumminess increased with rising melanin content, while springiness correspondingly decreased. Genome-wide association analysis identified 15,597,589 SNP loci. A total of 39 genes related to food quality were annotated, including one melanin-related lacquer enzyme gene, ACW004924. Real-time quantitative PCR validation of key genes identified for melanin and edible quality traits revealed results consistent with those from correlation analysis. The lacquer enzyme genes ACW004736, ACW006232, which regulate melanin synthesis, and the tyrosinase genes ACW001451, ACW002443, and ACW001003 were also identified in edible quality traits. These genes perform similar functions in GO-enriched metabolic processes, catalytic activity, and cellular structural complexes, as well as in KEGG-enriched pathways such as carbon metabolism and polysaccharide synthesis. They catalyze melanin synthesis and promote interactions between melanin and cell wall polysaccharides, chitin, and structural proteins, thereby stabilizing the cellular scaffold structure, jointly mediating the effect of melanin on the edible quality of A. cornea. The results supplement the downstream regulatory chain of catalytic enzymes and edible quality in the γ-L-glutaminyl-3,4-dihydroxybenzene (GDHB) pigment synthesis pathway, and form an information network of melanin synthesis, cell wall structure optimization, and edible quality regulation.