Jul 2026· Journal of Invertebrate Pathology· pp.
108707
· 0 citations· 37 references
Medicine
TL;DR
These findings provide the first insights into the multifaceted roles of intracellular β-N-acetylhexosaminidase Hex2 in B. bassiana, identifying a rational target for engineering insecticides with remained or even enhanced pesticidal efficacy.
Abstract
Entomopathogenic fungi such as Beauveria bassiana represent promising alternatives to chemical pesticides, yet their morphogenesis and environmental adaptation depend critically on dynamic cell wall remodeling. Despite the essential role of β-N-acetylhexosaminidase (Hex) in cell wall decomposition, its potential contributions to fungal biocontrol remain unexplored. Here, we identified and functionally dissected a previously uncharacterized homology, Hex2. Notably, Hex2 deficiency led to irregular cell wall structure by elevating chitin, N-glycan contents and protein N-/O-glycosylation levels within it. In addition, ΔHex2 mutant exhibited impaired development, including defects in sporulation, germination, and dimorphic transitions. These developmental defects were likely attributed to aberrant accumulation of cell wall components rather than insufficient ATP production. More interestingly, losing Hex2 enhanced fungal tolerance to oxidative stress cues though upregulation of antioxidant enzyme activities. Despite heightened oxidative-stress resistance, ΔHex2 mutant displayed significantly attenuated virulence against Galleria mellonella larvae, indicating that cell-wall disturbance and developmental defects might constitute the predominant causes of reduced pathogenicity. These findings provide the first insights into the multifaceted roles of intracellular β-N-acetylhexosaminidase Hex2 in B. bassiana, identifying a rational target for engineering insecticides with remained or even enhanced pesticidal efficacy.
Findings underscore a significant role for VdOMO in siderophore-associated iron acquisition, fungal development, stress adaptation, and the early stages of host colonization in V. dahliae.
Yusha Du, Lixinyu Sun, Kangwei Xie et al.· Frontiers in Plant Science· 0 citations
Colletotrichum fructicola, the primary causal agent of Glomerella leaf spot (GLS), is a destructive fungal pathogen of apple, whose underlying pathogenic mechanisms remain largely unknown. A previous transcriptomic analysis of infected leaves indicated induction of the transcription factor CfMBZ1. This study confirmed that CfMBZ1 is highly expressed in conidia and during early infection. To elucidate its function, we generated a ΔCfMBZ1 deletion mutant via homologous recombination. Phenotypic analysis revealed that ΔCfMBZ1 lost pathogenicity on apple leaves due to a blockage in appressorium-mediated host penetration, despite retaining the ability to form penetration pegs on cellophane. However, extension of invasive hyphae and necrotrophic growth in wounded apple fruit were unaffected. The mutant also exhibited defects in maintaining the integrity of the cell wall and cell membrane, as well as in tolerating oxidative and acid–base stress. Comparative transcriptome analysis suggested that CfMBZ1 regulates appressorium-mediated penetration by modulating genes involved in peroxisome biogenesis, lipid droplet metabolism, and other penetration-related pathways. Our findings reveal that CfMBZ1 plays a critical role in the pathogenesis of Glomerella leaf spot caused by C. fructicola.
Wenkui Liu, Wenxin Shi, Yecan Pan et al.· Phytopathology Research· 0 citations
It is reported that the methyltransferase FpLaeA is a global regulator essential for F. proliferatum pathogenicity and a target for integrated control of F. proliferatum and its associated mycotoxin risk.
Ling Wang, Shaoqing Tang, Weiyang Liao et al.· Journal of Agricultural and...· 0 citations
Cotton is an economically important cash crop severely affected by Verticillium wilt caused by Verticillium dahliae. Secreted cell-wall-degrading enzymes act as key virulence factors of this pathogen, yet the biological function of glucan 1,3-β-glucosidase remains largely uncharacterized. The gene VDAG_02814 (designated Vdbgl1) was previously found to be strongly induced during host infection. Here, combined approaches including gene knockout, host-induced gene silencing (HIGS), and transcriptomic analysis were utilized to characterize the function of Vdbgl1. The results showed that Vdbgl1 deletion retarded colony growth on PDA medium by 20.1–21.6%, decreased conidial yield by 20.2–46.7%, lowered spore germination rate by 30.7–32.9%, and weakened utilization of diverse carbon sources by 5.0–14.9%. The ΔVdbgl1 mutants also exhibited significantly increased sensitivity to cell wall-perturbing, osmotic, and membrane-damaging agents. Additionally, the ΔVdbgl1 mutants exhibited reduced disease index by approximately 19.1–27.7% and decreased fungal biomass by 42.7–61.8% in cotton; consistently, HIGS-mediated silencing of Vdbgl1 reduced the disease index by 25.7% and 26.7% and decreased fungal biomass by 48.1–71.5%. Transcriptome profiling of cotton roots infected by the ΔVdbgl1 mutant and the wild-type strain revealed 1007 down-regulated genes enriched in carbohydrate metabolism, cell wall degradation, and energy pathways, including 27 carbohydrate-active enzyme genes and 58 genes encoding cysteine-rich secreted proteins. Collectively, these findings indicated that Vdbgl1 coordinates carbon utilization, cell wall remodeling, and stress responses to regulate fungal development and pathogenicity, representing a promising target for cotton Verticillium wilt control.
Ruixiang Yuan, Yuanjing Li, Yongtai Li et al.· International Journal of Mol...· 0 citations
It is demonstrated that AaAtg4 is important for spore germination, siderophore biosynthesis, iron acquisition, oxidative stress resistance, and toxin production, thereby establishing its critical role in A. alternata virulence.
Hsin-Yu Lu, C. H. Y. Choo, Je-Jia Wu et al.· Fungal Genetics and Biology· 0 citations
A physical interaction is identified between AaSlt2 and Swi6/RlmA, suggesting that these components are critical for cell wall synthesis, which advances the understanding of pathogenic mechanisms of A. alternata and proposes potential strategies for controlling postharvest diseases.
Rong Li, Yiyang Liu, Li Li et al.· Virulence· 0 citations