Sesquiterpenyl epoxy-cyclohexenoids (SECs) that depend on a polyketide synthase–terpenoid synthase (PKS–TPS) pathway are widely distributed in plant pathogenic fungi. However, the biosynthesis and function of the acetylated SECs still remained cryptic. Here, we identified that AOL_s00215g 273 (273) was responsible for the acetylation of SECs in Arthrobotrys oligospora via the construction of Δ273, in which the acetylated SECs were absent and major antibacterial nonacetylated SECs accumulated. Mutant Δ273 displayed increased trap formation, and nematicidal and antibacterial activities but decreased fungal growth and soil colonization. Glutamine, a key precursor for NH₃ as a trap inducer, was highly accumulated, and biologically active phenylpropanoids and antibiotics were highly enriched in Δ273. The decreased endocytosis and increased autophagosomes, with the most upregulated genes involved in maintaining DNA and transcriptional stability and pathways related to coronavirus disease and exosome, suggested that lack of 273 might result in increased virus infection and the acetylation of SECs played a key role in fungal diverse antagonistic ability.

中文翻译：

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倍半萜烯环氧-环己烯的乙酰化通过代谢和转录调节线虫捕获真菌 Arthrobotrys oligospora 的真菌生长、抗逆性、内吞作用和致病性

依赖于聚酮化合物合酶-萜类合酶 (PKS-TPS) 途径的倍半萜基环氧-环己烯 (SEC) 广泛分布于植物病原真菌中。然而，乙酰化 SEC 的生物合成和功能仍然是神秘的。在这里，我们发现AOL_s 00215 g 273 (273) 负责通过构建 Δ273 对Arthrobotrys oligospora中的 SEC 进行乙酰化，其中乙酰化 SEC 不存在并且主要的抗菌非乙酰化 SEC 积累。突变体 Δ273 表现出增加的陷阱形成、杀线虫和抗菌活性，但减少了真菌生长和土壤定植。谷氨酰胺，NH _{3的关键前体}作为诱捕剂，Δ273高度积累，生物活性苯丙烷和抗生素高度富集。内吞作用减少和自噬体增加，其中上调最多的基因参与维持 DNA 和转录稳定性以及与冠状病毒疾病和外泌体相关的途径，表明缺乏 273 可能导致病毒感染增加，而 SEC 的乙酰化在真菌中起关键作用多样的对抗能力。