Changes of structures and biosynthesis/hydrolysis-associated genes expression of glucans at different Volvariella volvacea maturity stages

In the present study, effects of maturity stage on structural characteristics and biosynthesis/hydrolysis-associated genes expression of glucans from Volvariella volvacea fruit body were well investigated. Elongation and pileus expansion stages decreased total soluble carbohydrate and protein contents to 17.09 mg/g and 8.33 mg/g, and significantly accumulated the total amino acids contents to 32.37 mg/g. Yields of crude polysaccharides significantly increased to 8.12% at egg stage and decreased to 3.72% at pileus expansion stage. Purified VVP I-a and VVP I-b were proved to be alpha-glucans. The maturity process affected the monosaccharide compositions, decreased the molecular weights of VVP I-a and VVP I-b with decreased transcription levels of glucan biosynthesis-associated enzyme genes vvugp and vvgls and increased glucan hydrolysis-associated glucanase gene vvexg2 expression with no significant effects on backbone structures including glycosidic linkages and configu-rations. The findings would benefit for understanding change patterns of V. volvacea glucan structures and their biosynthesis/hydrolysis-associated genes expression at maturity stages.

Automated summary

This study investigated the effects of maturity stage on the structural characteristics and gene expression of glucans from Volvariella volvacea fruit body. The findings showed that maturity process affected the monosaccharide compositions, decreased the molecular weights of glucans, and regulated the expression levels of biosynthesis and hydrolysis-associated genes.