Oberti Héctor, Sessa Lucia, Oliveira-Rizzo Carolina, Di Paolo Andrés, Sanchez-Vallet Andrea, Seidl Michael F, Abreo Eduardo
Laboratorio de Bioproducción, Bioinsumos, INIA Las Brujas, Canelones, Uruguay.
Plataforma de Microscopía Confocal y Epifluorescencia, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
Pest Manag Sci. 2025 Apr;81(4):2323-2336. doi: 10.1002/ps.8631. Epub 2025 Jan 11.
Biological control methods involving entomopathogenic fungi like Beauveria bassiana have been shown to be a valuable approach in integrated pest management as an environmentally friendly alternative to control pests and pathogens. Identifying genetic determinants of pathogenicity in B. bassiana is instrumental for enhancing its virulence against insects like the resistant soybean pest Piezodorus guildinii. This study focused on comparative genomics of different B. bassiana strains and gene expression analyses to identify virulence genes in the hypervirulent strain ILB308, especially in response to infection of P. guildinii and growth on hydrocarbon HC15, a known virulence enhancer.
Strain ILB308 showed the highest number of virulence-related features, such as candidate virulence proteins, effectors, small secreted proteins and biosynthetic gene clusters. ILB308 also had a high percentage of unique DNA sequences, including six accessory scaffolds. Gene expression analysis at 4 days post inoculation revealed upregulation of known virulence factors, including Tudor domain proteins, LysM motif-containing proteins, subtilisin-like proteases and novel genes encoding secreted effectors and heat-labile enterotoxins. Growth on HC15 led to the upregulation of genes associated with oxidoreductase activity related to cuticular alkane degradation and fermentation metabolism/antioxidant responses in the hemolymph. The low number of known B. bassiana virulence genes points to novel or unknown mechanisms acting on the interaction between P. guildinii and strain ILB308.
The presence of accessory genomic regions and unique virulence genes in ILB308 may contribute to its higher virulence. These genes could be considered as potential targets for enhancing fungal virulence through genetic manipulation. © 2025 Society of Chemical Industry.
涉及球孢白僵菌等昆虫病原真菌的生物防治方法已被证明是害虫综合治理中的一种有价值的方法，可作为控制害虫和病原体的环境友好型替代方法。确定球孢白僵菌的致病遗传决定因素有助于提高其对诸如抗性大豆害虫豆荚草盲蝽等昆虫的毒力。本研究聚焦于不同球孢白僵菌菌株的比较基因组学和基因表达分析，以鉴定高毒力菌株ILB308中的毒力基因，特别是在应对豆荚草盲蝽感染以及在已知的毒力增强剂碳氢化合物HC15上生长时的毒力基因。
菌株ILB308表现出最多数量的与毒力相关的特征，如候选毒力蛋白、效应子、小分泌蛋白和生物合成基因簇。ILB308还具有高比例的独特DNA序列，包括六个辅助支架。接种后4天的基因表达分析显示已知毒力因子上调，包括Tudor结构域蛋白、含LysM基序的蛋白、枯草杆菌蛋白酶样蛋白酶以及编码分泌效应子和不耐热肠毒素的新基因。在HC15上生长导致与角质层烷烃降解相关的氧化还原酶活性以及血淋巴中的发酵代谢/抗氧化反应相关基因上调。已知的球孢白僵菌毒力基因数量较少，表明存在作用于豆荚草盲蝽与菌株ILB308之间相互作用的新机制或未知机制。
ILB308中辅助基因组区域和独特毒力基因的存在可能导致其更高的毒力。这些基因可被视为通过基因操作增强真菌毒力的潜在靶点。© 2025化学工业协会。
