糖基转移酶GL22535对灵芝生长与多糖合成的影响OA

Based on genome annotation and transcriptomic profiling of Ganoderma lucidum,this study functionally characterized the glycosyltransferase gene gl22535.Bioinformatic analysis and subcellular fluorescence localization revealed that GL22535 is a cytoplasmic glucosyltransferase belonging to the GT24 family.To elucidate its role,gl22535-overexpressing and silenced strains were constructed,and their fermentation performance and G.lucidum polysaccharide(GLP)production were evaluated.Overexpression strains exhibited slower growth,larger mycelial pellets,and accelerated carbon source consumption.The production of mycelial polysaccharides(MPS)and ex-tracellular polysaccharides(EPS)significantly increased,with the EPS able to achieve a 1.54-fold enhancement.In contrast,silenced strains showed enhanced growth,increased biomass,and reduced polysaccharide accumulation,indicating that gl22535 redirects carbon flux toward GLP biosynthesis.Analysis of polysaccharide molecular weight distribution and monosaccharide composition further indicated that altered gl22535 expression modifies the relative proportions of glucose,galactose,mannose,and xylose in both MPS and EPS.These compositional changes are likely mediated by transcriptional regulation of upstream genes involved in sugar-donor biosynthesis,thereby af-fecting nucleotide-sugar precursor allocation.Collectively,these results indicate that gl22535 plays a crucial role in GLP biosynthesis and mycelial morphogenesis,providing new insights into the complex biosynthetic network of GLP and laying a theoretical basis for elucidating the metabolic regulatory functions of glycosyltransferases in G.lucidum.