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.

Against the backdrop of China’s booming edible fungi industry, shortages and price hikes of traditional cultivation substrates have emerged as critical bottlenecks. Meanwhile, the disposal of a large amount of ginger straw produced during the ginger cultivation process is also a major challenge. To address these issues, this study explored ginger straw as an alternative substrate for Pleurotus geesteranus and Hericium erinaceus, focusing on the optimization of substrate formulas and their effects on the nutritional quality of the fungi. Superior strains were first screened, after which the addition ratios of ginger straw (10–40%) were optimized. Commercial characteristics, nutritional components, and safety indicators of the fruiting bodies were determined, and a comprehensive quality evaluation was conducted using the membership function method. Results indicated that excellent strains of both fungi were selected: the optimal ginger straw addition ratio was 15–30% for P. geesteranus and 15% for H. erinaceus. Compared with the conventional cottonseed hull substrate, the optimized formulas significantly increased the biological efficiency (BE) by 9.08–27.1% for P. geesteranus and 9.16% for H. erinaceus. They also improved the contents of key nutrients (e.g., proteins and amino acids), enhanced total antioxidant capacity, and optimized the composition of flavor-contributing amino acids. This study offers a novel approach for the efficient utilization of ginger straw, provides technical and theoretical support for the low-cost and high-quality cultivation of edible fungi, and contributes positively to the development of ecological circular agriculture.