Functions of a Glucan Synthase Gene in Mycelial Growth and Polysaccharide Production of .

Glucan synthase (GLS) gene is known to be involved in the fungal biosynthesis of cell wall, differentiation, and growth. In the present study, a glucan synthase gene () in the edible mushroom with a full sequence of 5927 bp encoding a total of 1781 amino acids was cloned and characterized for the first time. GFGLSp is a membrane protein containing two large transmembrane domains connected with a hydrophilic cytoplasmic domain. With a constructed dual promoter RNA silencing vector , a silencing transformant iGFGLS-3 had the lowest transcriptional expression level (26.1%) with a shorter length and thinner appearance of the mycelia, as well as decreased mycelial biomass and -polysaccharide production of 5.02 and 0.38 g/L, respectively. Further analysis indicated that silence influenced slightly the monosaccharide compositions and ratios of mycelial and -polysaccharide. These findings suggest that could affect mycelial growth and polysaccharide production by downregulating the glucan synthesis.