Flavonoids, which are abundant in plants, are recognized for their antioxidant and anticancer roles in clinical applications. However, little is known about the molecular basis of flavonoid biosynthesis in fungi. In this study, we found that inclusion of leachate of Korshinsk peashrub (Caragana korshinskii) in the fermentation medium increased the total flavonoid content of the edible fungus Auricularia cornea by 23.6% relative to that grown in a control medium. Combined transcriptomic and non-targeted metabolomic analysis of the flavonoid biosynthesis pathway in A. cornea illustrated that there are important metabolites in the phenylpropanoid, coumarin and isoflavonoid biosynthesis pathways. In addition, we found that certain homologous genes encode phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and chalcone isomerase (CHI) in these biosynthesis pathways. These results, in this study, provide a new line for studying the regulation of flavonoid production in edible fungi.

Ganoderic acid (GA) is an important secondary metabolite of Ganoderma lucidum with a diverse array of pharmacological properties. In this study, we found that exogenous ethylene increased the production of endogenous ethylene and ganoderic acid in G. lucidum. However, the mechanism by which ethylene is regulated remains unclear. As a result, we performed a combined transcriptomics and nontargeted metabolomics analysis to evaluate the regulatory mechanism of ethylene. A total of 4070 differentially expressed genes (1835 up-regulated and 2235 down-regulated) and 378 differentially accumulated metabolites (289 up-regulated and 89 down-regulated) were identified in all groups. The transcriptomics and nontargeted metabolomics data revealed that genes involved in the tricarboxylic acid (TCA) cycle, polyamine metabolic pathway, acetyl-CoA carboxylase (ACC) pathway, and triterpenoid metabolism were up-regulated, whereas the metabolic intermediates involved in these metabolic pathways were down-regulated. These findings imply that ethylene potentially accelerates normal glucose metabolism, hence increasing the number of intermediates available for downstream biological processes, including polyamine metabolism, ethylene synthesis pathway, and ganoderic acid biosynthesis. The findings will contribute significantly to our understanding of secondary metabolites biosynthesis in fungi.

Lyophyllum decastes, a common edible mushroom, is prized for its exceptional taste and rich nutritional composition. The concentrations of amino acids and polysaccharides in the fruiting body exhibited a dynamic increase throughout development, reaching their highest levels in the maturation stages, with values of 45,107.39 μg/g and 13.66 mg/g, respectively. Integrated metabolomic and transcriptomic analyses uncovered dynamic metabolites changing during the transition from vegetative growth to reproductive development. Several differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were identified, associated with secondary metabolite, amino acid, and carbohydrate metabolism. The shift in metabolites was linked to key nutrient synthesis, explaining the abundant production of amino acids and polysaccharides at maturity. Our results provide novel insights into the developmental biology of L. decastes, demonstrating that this mushroom is a valuable source of bioactive compounds and contributing to the optimization of cultivation strategies, as well as improving research into its application as a functional food and nutraceutical source.

Lyophyllum decastes is a commercially cultivated rare edible mushroom with high dietary and medicinal value. The mycelium physiological maturation was an important factor to the yield and quality of mushrooms obtained. However, it was impossible to obtain discriminative characteristics represented the maturity level of the mycelia from morphological features. In this article, we screened a candidate metabolite for evaluating the mycelium physiological maturation by metabolomic and transcriptomic analysis during mycelial vegetative growth stages of L. decastes. The results showed that mycelial vegetative growth 55 d had reached to physiological maturation according to the yield and quality of L. decastes, which the single bottle yield (307 g/bottle), the contents of flavonoids (2.94 mg/g dry weight), and 5 flavor amino acids (glutamate 177.90 μg/g, aspartate 95.74 μg/g, phenylalanine 31.68 μg/g, tyrosine 13.79 μg/g, and alanine 10.99 μg/g) were the highest. In addition, the metabolomic and transcriptomic analysis results showed that biosynthesis of secondary metabolites and amino acid had significant different during mycelial vegetative growth stages, and glutamine may be a candidate indicator to evaluate the mycelial physiological maturation. These findings contribute to improve our knowledge of mycelium physiological maturation and it will be used to increase mushroom yield and quality.

Substantial dye wastewater from the textile industry poses serious ecological threats. Spent mushroom substrate (SMS) offers a cost-effective and eco-friendly decolorization option, yet traditional methods are hindered by prolonged processing times. This study introduces a column decolorization (CD) method using Auricularia cornea SMS, demonstrating markedly higher efficiency and practicality. The CD method achieved over 50% decolorization for 10 of 12 tested dyes, outperforming conventional approaches for six dyes. Analyses via SEM, FTIR, and isotherm measurements indicated that the high efficiency stems from the SMS microstructure and functional groups, with mechanisms including electrostatic attraction, hydrogen bonding, and π-π conjugation, following Langmuir monolayer adsorption. The process requires no specific conditions, avoids extraction steps, and reduces treatment time to 4% of traditional methods. HPLC analysis further revealed partial biodegradation of Malachite Green, reducing its cytotoxicity. This work provides the first systematic comparison of SMS decolorization methods and a mechanistic analysis, supporting SMS application in dye wastewater treatment.