Hydrogen-rich water mediates redox regulation of the antioxidant system,mycelial regeneration and fruiting body development in Hypsizygus marmoreus

Hypsizygus marmoreus is an important industrialized mushroom, yet the lack of basic research on this fungus has hindered further development of its economic value. In this study, mycelia injured by scratching were treated with hydrogen-rich water (HRW) to investigate the involvement of the redox system in fruiting body development. Compared to the control group, damaged mycelia treated with HRW regenerated earlier and showed significantly enhanced fruiting body production. Antioxidant capacity increased significantly in damaged mycelia after HRW treatment, as indicated by higher antioxidant enzyme activities and antioxidant contents; the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) were also reduced at the mycelial regeneration stage after treatment with HRW. Furthermore, genes involved in ROS, Ca²⁺, MAPK and oxylipin signaling pathways were up-regulated by HRW treatment. In addition, laccase and manganese peroxidase activities and mycelial biomass were higher after HRW treatment, suggesting that HRW might enhance the substrate-degradation rate to provide more carbon sources for fruiting body production.     

Exogenous l-ascorbic acid regulates the antioxidant system to increase the regeneration of damaged mycelia and induce the development of fruiting bodies in Hypsizygus marmoreus

Hypsizygus marmoreus is an important commercial edible fungus, but the lack of basic studies on this fungus has hindered further development of its commercial value. In this study, we found that the treatment of damaged vegetative mycelia with 1 mM l-ascorbic acid (ASA) significantly increased the antioxidant enzyme activities (GPX, GR, CAT and SOD) and antioxidant contents (GSH and ASA) and reduced the ROS levels (H₂O₂ and O₂^-) in mechanically damaged mycelia. Additionally, this treatment increased mycelial biomass. At the reproductive stage, our results demonstrated that the treatment of damaged H. marmoreus mycelia with 2.24 mM ASA significantly increased the antioxidant enzyme activities (GPX, GR, GST, TRXR and CAT), endogenous ASA contents and GSH/GSSG ratios in different developmental stages and significantly decreased the MDA and H₂O₂ contents. Furthermore, this study showed that the expression levels of the antioxidant enzyme genes were consistent with the enzyme activities. Damaged mycelia treated with ASA regenerated 2–3 d earlier than the control group and showed significantly enhanced fruiting body production. These results suggested that exogenous ASA regulated mycelia intracellular ASA content to increase mycelial antioxidant abilities, induce the regeneration of damaged mycelia and regulate the development of fruiting bodies in H. marmoreus.     

桑树桑黄菌丝体和子实体基因差异表达分析

通过对桑树桑黄Sanghuangporus sanghuang菌丝体和子实体2个不同生长阶段的转录组进行分析,为研究桑黄子实体生长发育相关机制奠定基础。采用Illumina测序技术,对桑树桑黄菌株S23菌丝体和子实体2个不同生长发育阶段进行了全转录组测序。将转录组测序reads比对到参考序列上,菌丝体测序样本的reads比对率为82.89%;子实体测序样本的reads比对率为83%。基因差异表达分析显示,与菌丝体相比,子实体中显著上调表达基因为2 898个,显著下调表达基因为1 965个。经过Blast nr比对发现,桑黄菌在子实体阶段表达量上升的基因主要与各种氧化酶活性、疏水蛋白等相关;表达量下降的基因主要与糖类、氨基酸结合、运输等相关。基因本体（gene ontology,GO）富集分析表明,菌丝体及子实体两个阶段与跨膜转运相关的差异表达基因富集明显。代谢通路（pathway）富集分析表明,类固醇生物合成、精氨酸生物合成、丝裂原活化蛋白激酶（mitogen-activated protein kinase,MAPK）信号通路等差异基因富集明显。