Takei M, et al. Allergy Asthma Immunol Res. 2022 May;14(3):328-338. https://doi.org/10.4168/aair.2022.14.3.328

Pleurotus ostreatus is a widely cultivated edible fungus in China, renowned for its rich nutritional composition and diverse medicinal compounds. However, the quality of the currently published P. ostreatus genomes remained suboptimal, which limited in-depth research on its evolution, growth, and development. In this study, we conducted a chromosome-level genome assembly of the monokaryotic basidiospore strain PC80. The assembled genome spanned 40.6 Mb and consisted of 15 scaffolds. Ten of these scaffolds contained complete telomere-to-telomere structures. The scaffold N50 value was 3.6 Mb. Genome annotation revealed 634 carbohydrate-active enzyme (CAZyme) family genes. Through collinearity analysis, we further confirmed that the PC80 genome exhibited higher completeness and greater accuracy compared to the currently published genomes of P. ostreatus. At the matA locus of PC80, three hd1 genes and one hd2 gene were identified. At the matB locus, seven pheromone receptor genes and two pheromone precursor genes were detected. Further phylogenetic analysis indicated that three of these pheromone receptor genes are likely to have mating-specific functions. This complete genome assembly could provide a foundation for future genomic and genetic studies, facilitate the identification of key genes related to growth and developmental regulation, and promote technological innovations in P. ostreatus breeding and efficient utilization.

Cry j 7 is a 7 kDa cysteine-rich gibberellin regulatory protein (GRP) with six disulfide bonds. It was isolated from Japanese cedar as the pollen allergen in this study. It exhibits cross-reactivity with food allergens such as Pru p 7 from peach and causes pollen-food allergy syndrome (PFAS). In this work, recombinant Cry j 7 and Pru p 7 were successfully overexpressed using Pichia pastoris in a high-cell-density fermentation culture, and pure proteins were purified by reverse-phase HPLC. The characterization of Cry j 7 and Pru p 7 were performed by MS, CD, and ¹H-NMR experiments to confirm the correct native conformation of Cry j 7 as well as Pru p 7. When compared, the results showed that Cry j 7 exhibits excellent stability in disulfide linkages and preserves its original structure up to 90 °C in various pH buffers in comparison to Pru p 7. Notably, NMR analyses indicated the greater mobility in the α-helix and loop regions of S38-C47 in Pru p 7 compared to those of Cry j 7. Furthermore, our results showed that the sensitivity of Cry j 7 to enzyme digestion differed from that of Pru p 7: Cry j 7 was more susceptible to proteolysis, while Pru p 7 displayed better resistance in the gastrointestinal tract. These variations in structural stability and sensitivity to proteolysis provide valuable insights into the allergenicity within the GRP family.

Global food security and climate mitigation goals are placing unprecedented demands on agricultural systems to simultaneously improve soil productivity and reduce carbon emissions. Spent mushroom substrate (SMS), the mushroom industry’s principal waste stream, offers considerable recycling potential, yet its influence on dissolved organic carbon (DOC) chemistry and soil aggregate stability remains unclear. We tested four SMS return regimes on a medium-textured fluvo-aquic soil: CK, 0 t·ha⁻¹; ORS, 22.5 t/ha; ERS, 22.5 t/ha; and SRS, 45 t/ha in total, with 22.5 t/ha applied per SMS return event. It was found that SMS improved soil structural stability across all regimes, with SRS delivering the strongest effects. Compared with CK, SRS raised the proportions of >2 mm and 0.25–2 mm aggregates by 31.62% and 33.42%, while the mean weight diameter (MWD) and geometric mean diameter (GMD) increased by 23.25% and 22.68%. SMS also elevated aromatic carbon abundance, DOC concentration, UV254, and SUVA254. Fluorescence EEM-PARAFAC resolved DOC into three component: namely, two humic-like and one protein-like, and SMS expanded the relative contribution of the humic-like C1 fraction. Overall, under the tested fluvo-aquic soil and wheat–maize rotation conditions, SMS return was associated with changes in DOC composition, higher aggregate stability, and greater aggregate-associated carbon accumulation. These findings suggest that SMS return may be a promising strategy for improving soil structure and recycling agricultural waste under similar field conditions, but its broader applicability requires further validation.