Biological control potential of entomopathogenic fungi depending on conidiation capacity, conidial stress tolerance and virulence can be improved through genetic engineering. To explore a possible role of trehalose biosynthesis pathway in improving fungal pest-control potential, we characterized biological functions of trehalose-6-phosphate phosphatase (BbTPP) in Beauveria bassiana, an insect mycopathogen that serves as a main source of fungal insecticides. Deletion of BbTPP resulted in abolished trehalose biosynthesis, reduced conidiation capacity, decreases in conidial thermotolerance and UV-B resistance, increased hyphal sensitivities to chemical stresses, and attenuated virulence. By contrast, over-expression of BbTPP led to increased trehalose accumulation, decreased T6P accumulation, and enhanced stress tolerance and virulence despite little impact on growth and conidiation under normal conditions. These results indicate that BbTPP serves as not only a key player in control of trehalose biosynthesis required for multiple cellular functions but also a potential candidate to be exploited for genetic improvement of fungal potential against insect pests.

中文翻译：

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海藻糖生物合成、无性发育、抗逆性和昆虫真菌病原体毒力中海藻糖-6-磷酸磷酸酶的表征

取决于分生孢子能力、分生孢子胁迫耐受性和毒力的昆虫病原真菌的生物控制潜力可以通过基因工程来提高。为了探索海藻糖生物合成途径在提高真菌害虫防治潜力方面的可能作用，我们表征了 6-磷酸海藻糖磷酸酶 (BbTPP) 在白僵菌中的生物学功能，白僵菌是一种昆虫真菌病原体，是真菌杀虫剂的主要来源。BbTPP 的缺失导致海藻糖生物合成被破坏，分生孢子能力降低，分生孢子耐热性和 UV-B 抗性降低，菌丝对化学胁迫的敏感性增加，毒力减弱。相比之下，BbTPP 的过度表达导致海藻糖积累增加，T6P 积累减少，尽管在正常条件下对生长和分生孢子的影响很小，但增强了胁迫耐受性和毒力。这些结果表明，BbTPP 不仅是控制多种细胞功能所需的海藻糖生物合成的关键参与者，而且还是潜在的候选物，可用于遗传改良真菌对害虫的潜力。