Gangzheng Wang

Type 2 diabetes mellitus (T2MD) has reached pandemic proportions, imposing a substantial global burden on both individual health and overall quality of life. Polysaccharides from Cordyceps guangdongensis fruiting body (CGP) have been shown to alleviate hyperglycemia in obese mice. This study firstly revealed the anti-diabetes and multi-target mechanisms of CGP in T2MD mice induced by a high-fat diet and 100 mg/kg streptozotocin. After six weeks of CGP intervention, we observed notable improvement in body weight loss, fasting blood glucose, insulin resistance, hyperlipidemia, hepatic transaminase activities and antioxidant enzyme activities, outperforming metformin in mitigating some hepatic and renal indicators. Furthermore, CGP remodeled gut microbiota by enriching the gram-negative bacteria Odoribacter and decreasing the gram-positive bacteria Olsenella and Blautia, while elevating short chain fatty acids (SCFAs), especially propionic acid and acetic acid. These observed microbial and SCFA changes were strongly negatively correlated with adverse indicators of glucolipid metabolism and liver function. Hepatic metabolome identified ergothioneine as a key antioxidant metabolite, and renal transcriptome revealed downregulation of complement and coagulation cascade genes (F2, Fga, Fgb and Fgg) and modulation of peroxisome proliferator-activated receptors PPAR and lipid metabolism-related genes, thereby improving glucolipid metabolism disorder and organ injuries in T2MD mice. Collectively, these findings positioned CGP as a promising multi-target functional food ingredient for T2MD and related complications, acting via a regulatory axis involving in the gut microbiota, SCFA, glucolipid metabolism and related gene expression, and antioxidant capacity.

Lentinula edodes (shiitake mushrooms) is heavily affected by the infection of Trichoderma atroviride, causing yield loss and decreases quality in shiitake mushrooms. The selection and breeding of fungal-resistant L. edodes species are an important approach to protecting L. edodes from T. atroviride infection. Herein, a highly resistant L. edodes strain (Y3334) and a susceptible strain (Y55) were obtained by using a resistance evaluation test. Transcriptome analyses and qRT-PCR detection showed that the expression level of LeTLP1 (LE01Gene05009) was strongly induced in response to T. atroviride infection in the resistant Y3334. Then, LeTLP1-silenced and LeTLP1-overexpression transformants were obtained. Overexpression of LeTLP1 resulted in resistance to T. atroviride. Compared with the parent strain Y3334, LeTLP1-silenced transformants had reduced resistance relative to T. atroviride. Additionally, the LeTLP1 protein (Y3334) exhibited significant antifungal activity against T. atroviride. These findings suggest that overexpression of LeTLP1 is a major mechanism for the resistance of L. edodes to T. atroviride. The molecular basis provides a theoretical basis for the breeding of resistant L. edodes strains and can eventually contribute to the mushroom cultivation industry and human health.

Our previous study found that LeDnaJ07 RNAi decreased Lentinula edodes resistance to heat stress and Trichoderma atroviride infection. In this study, the structure and function of the LeDnaJ07 gene was analyzed by gene cloning and overexpression in L. edodes stress-sensitive strain YS55 via the Agrobacterium-mediated transformation method. Transformants were confirmed by qRT-PCR, fluorescence observation and Southern blotting. Overexpression of LeDnaJ07 in YS55 not only enhanced L. edodes mycelial resistance to heat stress but also facilitated mycelial growth. In the presence of heat stress, the intracellular IAA content showed a significant increase in the two LeDnaJ07 overexpression strains but only a slight change in the YS55 wild type strain. Moreover, the interaction between LeDnaJ07 and LetrpE was demonstrated via Y2H and BiFC assays. These results suggested that LeDnaJ07 may be involved in regulating IAA biosynthesis and the resistance of L. edodes to heat stresses via interacting with LetrpE.

Workflows of transcriptome and proteome analyses across the differentially developmental stages of C. guangdongensis. My, Mycelial stages; P, Primordial stage; YFB, Young fruiting body stage; DFB, Developed fruiting body stage; MFB, Mature fruiting body stage.

Lentinula edodes is the most consumed mushroom in Asia due to its nutritional and medicinal values, and the optimal reference gene is crucial for normalization of its gene expression analysis. Here, the expression stability of 18 candidate reference genes (CRGs) in L. edodes was analyzed by three statistical algorithms (geNorm, NormFinder and BestKeeper) under different stresses (heat, cadmium excess and Trichoderma atroviride infection), different substrates (straw, sawdust and corn stalk) and different development stages (mycelia, primordia and fruit bodies). Among the 18 CRGs, 28S, Actin and α-tub exhibited the highest expression stability in L. edodes under all conditions, while GPD, SPRYP and MSF showed the least stable expression. The best reference gene in different conditions was different. The pairwise variation values showed that two genes would be sufficient for accurate normalization under different conditions of L. edodes. This study will contribute to more accurate estimation of the gene relative expression levels under different conditions using the optimal reference gene in qRT-PCR (quantitative reverse transcription polymerase chain reaction) analysis.