Fusarium wilt is a severe and worldwide disease in potato cultivation. In this study, Fusarium foetens was first identified as the pathogen of potato wilt. Bacillus subtilis SF1 has the potential for controlling potato wilt induced by F. foetens, resulting in a mycelium growth inhibition of 52.50 ± 2.59% in vitro and a significant decrease in incidence rate by 45.56% in vivo. This research highlighted the antifungal activity of surfactin from B. subtilis SF1 and attempted to reveal the unknown antifungal mechanisms. Surfactin inhibited F. foetens mycelium growth beyond the concentration of 20 μg/μL. Surfactin-treated mycelium appeared to have morphological malformation. Surfactin enhanced reduced glutathione production and caused the increase in values of the extracellular fluids in OD260 and OD280. Surfactin induced differential protein expression and changed the genes’ transcription levels. Surfactin binds to fungal DNA via groove-binding mode, with a binding constant of K_b 2.97 × 10⁴ M⁻¹. Moreover, B. subtilis SF1 harbored genes encoding plant-promoting determinants, making potato seedlings grow vigorously. The results will help provide a comprehensive understanding of the mechanisms of surfactin against filamentous fungi and the application of surfactin-producing microbial in the biocontrol of plant pathogenic fungi.

Lysine acetylation of proteins, a major post-translational modification, plays a critical regulatory role in almost every aspects in both eukaryotes and prokaryotes. Yarrowia lipolytica, an oleaginous yeast, is considered as a model for bio-oil production due to its ability to accumulate a large amount of lipids. However, the function of lysine acetylation in this organism is elusive. Here, we performed a global acetylproteome analysis of Y. lipolytica ACA-DC 50109. In total, 3163 lysine acetylation sites were identified in 1428 proteins, which account for 22.1% of the total proteins in the cell. Fifteen conserved acetylation motifs were detected. The acetylated proteins participate in a wide variety of biological processes. Notably, a total of 65 enzymes involved in lipid biosynthesis were found to be acetylated. The acetylation sites are distributed in almost every type of conserved domains in the multi-enzymatic complexes of fatty acid synthetases. The provided dataset probably illuminates the crucial role of reversible acetylation in oleaginous microorganisms, and serves as an important resource for exploring the physiological role of lysine acetylation in eukaryotes.

Fungal diseases not only reduce the yield of edible mushrooms but also pose potential threats to the preservation and quality of harvested mushrooms. Cobweb disease, caused primarily by fungal pathogens from the Hypocreaceae family, is one of the most significant diseases affecting edible mushrooms. Deciphering the genomes of these pathogens will help unravel the molecular basis of their evolution and identify genes responsible for pathogenicity. Here, we present high-quality genome sequences of three cobweb disease fungi: Hypomyces aurantius Cb-Fv, Cladobotryum mycophilum CB-Ab, and Cladobotryum protrusum CB-Mi, isolated from Flammulina velutipes, Agaricus bisporus, and Morchella importuna, respectively. The assembled genomes of H. aurantius, C. mycophilum, and C. protrusum are 33.19 Mb, 39.83 Mb, and 38.10 Mb, respectively. This is the first report of the genome of H. aurantius. Phylogenetic analysis revealed that cobweb disease pathogens are closely related and diverged approximately 17.51 million years ago. CAZymes (mainly chitinases, glucan endo-1,3-beta-glucosidases, and secondary metabolite synthases), proteases, KP3 killer proteins, lipases, and hydrophobins were found to be conserved and strongly associated with pathogenicity, virulence, and adaptation in the three cobweb pathogens. This study provides insights into the genome structure, genome organization, and pathogenicity of these three cobweb disease fungi, which will be a valuable resource for comparative genomics studies of cobweb pathogens and will help control this disease, thereby enhancing mushroom quality.

White Hypsizygus marmoreus is a popular edible mushroom. Its mycelium is easy to be contaminated by Penicillium, which leads to a decrease in its quality and yield. Penicillium could compete for limited space and nutrients through rapid growth and produce a variety of harmful gases, such as benzene, aldehydes, phenols, etc., to inhibit the growth of H. marmoreus mycelium. A series of changes occurred in H. marmoreus proteome after contamination when detected by the label-free tandem mass spectrometry (MS/MS) technique. Some protein s with up-regulated expression worked together to participate in some processes, such as the non-toxic transformation of harmful gases, glutathione metabolism, histone modification, nucleotide excision repair, clearing misfolded proteins, and synthesizing glutamine, which were mainly used in response to biological stress. The proteins with down-regulated expression are mainly related to the processes of ribosome function, protein processing, spliceosome, carbon metabolism, glycolysis, and gluconeogenesis. The reduction in the function of these proteins affected the production of the cell components, which might be an adjustment to adapt to growth retardation. This study further enhanced the understanding of the biological stress response and the growth restriction adaptation mechanisms in edible fungi. It also provided a theoretical basis for protein function exploration and edible mushroom food safety research.

Cyclobalanopsis glauca (Thunb.) Oerst. is one of the most widely distributed species of evergreen broad-leaved tree in subtropical areas of China. It is also grown in Korea, Japan, and India. Because of its beautiful shape, C. glauca is commonly used for greening gardens and walkways. In July 2018, leaf spots on C. glauca were observed in Zhejiang province (Lishui, N: 28°26' 6.75";E: 119°54'11.22), China. About 70% of the trees were found to be diseased, with approximately 50% of leaves showing symptoms. The symptoms on C. glauca leaves initially appeared as small brown-yellow spots which gradually expanded, developing a light brown central and dark brown to black margin. The spots ranged from 4 to 15 mm in diameter. Ten symptomatic fragments measuring approximately 5×5 mm from each leaf were surface disinfested with 70% ethanol for 30 s, and then they were rinsed in sterile distilled water and placed on potato dextrose agar (PDA) medium at 25 °C in the dark for five days. Segments of colony perimeters were then transferred to new plates. The colonies initially produced white mycelia that later turned gray-white with pink and occasionally black dots scattered on the surface of the mycelium. Spores were aseptate, cylindrical, 8 to 15 μm in length, and 3 to 5 μm wide, most with rounded ends, a few with one apex round and the other fusiform, as described for Colletotrichum gloeosporioides (Penz.) Sacc. (Agostini et al. 1993). The internal transcribed spacer rDNA (ITS: MK758005) and two nuclear protein-coding genes (CHS: MK784770, ACT: MK784769) were amplified with ITS1/ITS4, CHS-79F/CHS-345, and ACT-512F/ACT-783R, respectively (Weir et al. 2012). The sequence had 99.61% identity to GQ485605 for ITS, 99.56% to GQ856782 for ACT, and 100% to GQ856733 for CHS of C. gloeosporioides CBS 953.97 in GenBank, respectively. To fulfill Koch's postulates, spores (1×108) of the isolate were sprayed onto leaves of twelve 2-year-old C. glauca plants (at least six leaves per plant). The fungus was inoculated on one side of each leaf, and distilled water was used as a mock inoculated control on the other side. The plants were cultivated in the greenhouse to maintain high humidity and a temperature near 25 °C. After 9 days, 100% of the leaf halves that had been inoculated had symptoms identical to those observed on affected C. glauca leaves in the field, while no symptoms were observed on the mock inoculated half of each leaf. The fungus was reisolated from the symptoms and identified as C. gloeosporioides using techniques previously described. To our knowledge, this is the first report of C. gloeosporioides infecting C. glauca in China. This study will establish a foundation for the further study of C. gloeosporioides to address the disease effectively. References: Agostini, J. P., et al. 1993. Phytopathology. 82:1177. Weir, B. S., et al. 2012. Stud. Mycol. 73:115. This work was supported by the National Science Foundation for Young Scientists of China (31800035).