Abstract：
Beauveria bassiana (Bb) is a widespread entomopathogenic fungus widely used in agriculture for crop protection. Other than pest control, fungi belonging to the B. bassiana complex represent an important microbial resource in agroecosystems, considering their multiple interactions with other microorganisms as antagonists of phytopathogens, or with plants as endophytic colonizers and growth promoters. Here, we characterised field collected or commercial isolates of B. bassiana relative to the environmental factors that affect their growth. We further compared the metabolome, the entomopathogenic potential and biocontrol activity of the tested isolates respectively on the insect pest Spodoptera littoralis or against the fungal plant pathogen Fusarium oxysporum. Our analysis revealed that the B. bassiana complex is characterised by a high level of inter-isolate heterogeneity in terms of nutritional requirements, establishment of intra- or inter-kingdom interactions, and the nature of metabolites produced. Interestingly, certain B. bassiana isolates demonstrated a preference for low nutrient plant-derived media, which hints at their adaptation towards an endophytic lifestyle over a saprophytic one. In addition, there was a noticeable variation among different B. bassiana isolates in their capacity to kill S. littoralis larvae in a contact infection test, but not in an intrahaemocoelic injection experiment, suggesting a unique level of adaptability specific to the host. On the other hand, most B. bassiana isolates exhibited similar biocontrol efficacy against the soil-dwelling ascomycete F. oxysporum f. sp. lycopersici, a pathogen responsible for vascular wilt disease in tomato plants, effectively averting wilting. Overall, we show that the effectiveness of B. bassiana isolates can greatly vary, emphasising the importance of isolate selection and nutritional adaptability consideration for their use in sustainable agriculture.
摘要：
球孢白僵菌（Bb）是一种广泛的昆虫病原真菌，广泛用于农业中的作物保护。除虫害防治外，属于球孢芽孢杆菌复合体的真菌是农业生态系统中重要的微生物资源，考虑到它们与其他微生物作为植物病原体拮抗剂的多重相互作用，或与植物作为内生定植剂和生长促进剂。这里,我们表征了田间收集的或商业分离的巴氏杆菌相对于影响其生长的环境因素。我们进一步比较了代谢组，测试的分离株分别对昆虫害虫斜纹夜蛾或针对真菌植物病原体尖孢镰刀菌的昆虫病原潜力和生物防治活性。我们的分析显示，在营养需求方面，玄武岩复杂的特点是高水平的分离物之间的异质性，建立王国内部或王国之间的相互作用，以及产生的代谢物的性质。有趣的是,某些球孢芽孢杆菌分离株表现出对低营养植物来源培养基的偏好，这暗示了他们对内生植物生活方式的适应，而不是腐生生活方式。此外,在接触感染试验中，不同的球孢细辛芽孢杆菌分离株在杀死盘状芽孢杆菌幼虫的能力上有明显的差异，但不是在血液腔内注射实验中，表明特定于宿主的独特适应性水平。另一方面,大多数球孢芽孢杆菌分离株对土壤中的子囊菌F.尖孢孢菌表现出相似的生物防治功效。lycopersici,一种引起番茄植物维管枯萎病的病原体，有效避免枯萎。总的来说,我们表明，球孢芽孢杆菌分离株的有效性可以有很大差异，强调分离株选择和营养适应性考虑在可持续农业中使用的重要性。
