Mycology-An International Journal On Fungal Biology
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2025
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IF 4.4
Yue Zhang,Yunxiao Luo,Xiaoyu Liu,Jun Li,Yuxian Xia,Yueqing Cao
In pathogenic fungi, N-glycosylated cell wall proteins serve as initial contact points during interactions with host. In the process of protein N-glycosylation, N-linked glycans are processed by α-glucosidases I (Gls1) and II (Gls2) to trim the final two glucose residues to facilitate glycoprotein maturation. In this study, we identified and characterized MaGls2 by disrupting its catalytic subunit MaGls2α, in the entomopathogenic fungus Metarhizium acridum. MaGls2α was found to localize to the endoplasmic reticulum. Deletion of MaGls2α resulted in earlier conidiation and increased conidial yield, but impaired colony growth and diminished tolerance to various stresses. ∆MaGls2α mutant exhibited disrupted cell wall architecture, characterized by a smoother surface, increased wall thickness, reduced β-1,3-glucan, and elevated chitin content. Bioassays demonstrated that the ∆MaGls2α mutant exhibited significantly attenuated virulence and triggered a stronger immune response from the host. Further analysis of the infection process revealed that reduced cell wall hydrophobicity and impaired appressorium formation in ∆MaGls2α mutant led to its decreased ability to penetrate the insect cuticle. Furthermore, the mutant showed slowed growth in host hemolymph, hindering successful colonization. These results indicate that MaGls2α is essential for maintaining proper cell wall composition and structure, thereby influencing fungal growth, conidiation, stress tolerance, and pathogenicity.
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DOI
高影响因子
PLoS Pathogens
·
2024
·Vol. 20
·期 7
·e1012431
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IF 5.5
Xiaoyu Liu,Nemat O. Keyhani,Hong Liu,Yue Zhang,Yuxian Xia,Yueqing Cao
Reactive carbonyl and oxygen species (RCS/ROS), often generated as metabolic byproducts, particularly under conditions of pathology, can cause direct damage to proteins, lipids, and nucleic acids. Glyoxal oxidases (Gloxs) oxidize aldehydes to carboxylic acids, generating hydrogen peroxide (H 2 O 2 ). Although best characterized for their roles in lignin degradation, Glox in plant fungal pathogens are known to contribute to virulence, however, the mechanism underlying such effects are unclear. Here, we show that Glox in the insect pathogenic fungus, Metarhizium acridum , is highly expressed in mycelia and during formation of infection structures (appressoria), with the enzyme localizing to the cell membrane. MaGlox targeted gene disruption mutants showed RCS and ROS accumulation, resulting in cell toxicity, induction of apoptosis and increased autophagy, inhibiting normal fungal growth and development. The ability of the MaGlox mutant to scavenge RCS was significantly reduced, and the mutant exhibited increased susceptibility to aldehydes, oxidative and cell wall perturbing agents but not toward osmotic stress, with altered cell wall contents. The Δ MaGlox mutant was impaired in its ability to penetrate the host cuticle and evade host immune defense resulting in attenuated pathogenicity. Overexpression of MaGlox promoted fungal growth and conidial germination, increased tolerance to H 2 O 2 , but had little to other phenotypic effects. Transcriptomic analyses revealed downregulation of genes related to cell wall synthesis, conidiation, stress tolerance, and host cuticle penetration in the Δ MaGlox mutant. These findings demonstrate that MaGlox -mediated scavenging of RCS is required for virulence, and contributes to normal fungal growth and development, stress resistance.
The ability of organisms to detoxify reactive metabolic byproducts is crucial for normal development, stress resistance, and where applicable, pathogenesis. Here, using the insect pathogenic fungus, Metarhizium acridum , we show that a glyoxal oxidase acts to detoxify cellular reactive carbonyl species (RCS) as well as leading to decreased reactive oxygen species (ROS) levels by alleviating aldehydes accumulation which can trigger ROS production. Mutants deficient in MaGlox showed increased levels of RCS/ROS leading to increased autophagy and apoptosis, resulting in impaired fungal growth, development, and reduced virulence. These findings link Glox mediated RCS/ROS detoxification to cell degradation/turnover processes and cell death, impacting fungal pathogenicity and development.
研究领域:
微生物学
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真菌学
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病理学
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细胞生物学
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植物病理学
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高影响因子
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