Screening of the Candidate Metabolite to Evaluate the Mycelium Physiological Maturation of Lyophyllum decastes Based on Metabolome and Transcriptome Analysis

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.