Selenium-modulated changes in growth and nutritional quality of Auricularia auricula mycelia: physiological responses and multi-omics mechanisms.

This study used an integrated multi-omics strategy to elucidate how selenium enhances physiological adaptation and nutritional quality in Auricularia auricula mycelia. Optimal selenium (40 mg/L) promoted growth, elevated extracellular enzyme activities (laccase, xylanase, cellulase), and increased antioxidant capacity, crude melanin, and unsaturated fatty acids. Transcriptomics identified key genes (abcB, fer1, RDH13, SPBC30D10.05c, hsp60) associated with ABC transport, antioxidant defense, and fatty acid metabolism. Metabolomics revealed core metabolites (tryptophan, DKMTP (1,2-dihydroxy-3-keto-5-methylthiopentene), trimethylglycine, pyruvic acid) that were significantly enriched in pathways including amino acid, nicotinic acid, and arginine metabolism. Correlation network analysis showed these metabolites interact with gene modules for antioxidant defense, selenium tolerance, and energy metabolism, coordinating stress adaptation and metabolic change. This work establishes the first multi-omics gene-metabolite interaction framework for selenium response in A. auricula, providing a theoretical basis and molecular targets for cultivation, processing, and breeding of high‑selenium, high-nutrition functional products.