Project description:The white button mushroom Agaricus bisporus is the most widely produced edible fungus with a great economical value. Its commercial cultivation process is often performed on wheat straw and animal manure based compost that mainly contains lignocellulosic material as a source of carbon and nutrients for the mushroom production. As a large portion of compost carbohydrates are left unused in the current mushroom cultivation process, the aim of this work was to study wild-type A. bisporus strains for their potential to convert the components that are poorly utilized by the commercial strain A15. Growth profiling suggested different abilities for several A. bisporus strains to use plant biomass derived polysaccharides, as well as to transport and metabolize the corresponding monomeric sugars. Six wild-type isolates with diverse growth profiles were compared for mushroom production to A15 strain in semi-commercial cultivation conditions. Transcriptome and proteome analyses of the three most interesting wild-type strains and A15 indicated that the unrelated A. bisporus strains degrade and convert plant biomass polymers in a highly similar manner. This was also supported by the chemical content of the compost during the mushroom production process. Our study therefore reveals a highly conserved physiology for unrelated strains of this species during growth in compost.
Project description:Reproductive-stage heat stress reduces rice yield and grain appearance quality, even in modern heat-resilient cultivars. Although our previous work showed that green manure can lessen ripening heat damage in the widely grown but heat-susceptible Japanese cultivar Koshihikari, it remains unclear whether similar benefits occur in heat-resilient cultivars and how green manure influences source–sink molecular responses during ripening. Here, using the heat-resilient cultivar Nijinokirameki, we tested whether green manure alleviates ripening heat stress by modifying panicle thermal status, nitrogen assimilation, and early endosperm stress responses. Green manure increased flag-leaf size and tiller (panicle) number and enhanced ripening-stage heat resilience by lowering panicle temperature without a meaningful phenological shift. Consistent with reduced heat load at the target organ, endosperm RNA-seq at 5 days after flowering (DAF) revealed weaker induction of heat-responsive programs under green manure, accompanied by increased grain protein content and reduced chalkiness classes (e.g., white milky, and white belly and back kernels). In parallel, shoot nitrogen contents at panicle formation stage were increased and flag-leaf RNA-seq at 5 DAF showed upregulation of ASN1 and NADH-GOGAT2, suggesting contribution to nitrogen assimilation in source organs and nitrogen allocation to grains. Together, these results link a sustainable fertility practice to tissue-scale heat stress mitigation and coordinated source–sink transcriptional responses at ripening that reflects enhanced grain protein accumulation and appearance quality under green manure treatment.
Project description:Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that over a third of the genes induced after 6 h of exposure to wheat straw were also induced during 6 h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides.
Project description:Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that over a third of the genes induced after 6 h of exposure to wheat straw were also induced during 6 h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides. Eight samples in total consisting of duplicate shake flask Aspergillus niger cultures from four conditions: 48h glucose, 6 h starvation, 6 h wheat straw, 24 h starvation