Terpene Synthase Genes Originated from Bacteria through Horizontal Gene Transfer Contribute to Terpenoid Diversity in Fungi
Terpene Synthase Genes Originated from Bacteria through Horizontal Gene Transfer Contribute to Terpenoid Diversity in Fungi
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DOI：
10.1038/s41598-019-45532-1
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发表时间：
2019-06-25
影响因子：
4.6
通讯作者：
Chen, Feng
中科院分区：
文献类型：
--
作者：
Jia, Qidong;Chen, Xinlu;Chen, Feng
真菌是分布广泛的成功真核生物。它们被认为是次生代谢物的丰富生产者，特别是萜类化合物，这对真菌与环境的相互作用很重要。水平基因转移（HGT）是真菌遗传创新的重要机制。然而，目前尚不清楚HGT是否在创造真菌萜类化合物的巨大化学多样性中发挥了作用。在这里，我们报道真菌通过HGT从细菌获得了萜烯合成酶基因（tps），该基因编码萜类生物合成的关键酶。系统发育分析将来自不同类群的大多数真菌和细菌TPS基因划分为两个分支，表明了古老的分化。在细菌TPS分支中嵌套了许多真菌TPS基因，这些基因被推断为HGT的结果。其中包括来自8种相关昆虫病原真菌的9个真菌TPS基因的单系分支，称为细菌TPS样基因BTPSL，其中包括来自绿僵菌属6种真菌的7个TPS。体外酶分析表明，绿僵菌属的7个BTPSL基因编码的活性酶具有两种一般产物谱的倍半萜合成酶活性。通过分析两种复活的祖先BTPSLs和一种密切相关的细菌TPS的催化活性，可以追溯BTPSLs在高温转化后从细菌到真菌的功能进化轨迹以及在绿僵菌中的功能分化。以M. brunneum为模型物种，BTPSLs和典型的真菌TPS均参与体内萜类化合物的产生，说明细菌TPS基因的HGT作为促进真菌萜类化合物多样性的机制的普遍重要性。
Fungi are successful eukaryotes of wide distribution. They are known as rich producers of secondary metabolites, especially terpenoids, which are important for fungi-environment interactions. Horizontal gene transfer (HGT) is an important mechanism contributing to genetic innovation of fungi. However, it remains unclear whether HGT has played a role in creating the enormous chemical diversity of fungal terpenoids. Here we report that fungi have acquired terpene synthase genes (TPSs), which encode pivotal enzymes for terpenoid biosynthesis, from bacteria through HGT. Phylogenetic analysis placed the majority of fungal and bacterial TPS genes from diverse taxa into two clades, indicating ancient divergence. Nested in the bacterial TPS clade is a number of fungal TPS genes that are inferred as the outcome of HGT. These include a monophyletic clade of nine fungal TPS genes, designated as BTPSL for bacterial TPS-like genes, from eight species of related entomopathogenic fungi, including seven TPSs from six species in the genus Metarhizium. In vitro enzyme assays demonstrate that all seven BTPSL genes from the genus Metarhizium encode active enzymes with sesquiterpene synthase activities of two general product profiles. By analyzing the catalytic activity of two resurrected ancestral BTPSLs and one closely related bacterial TPS, the trajectory of functional evolution of BTPSLs after HGT from bacteria to fungi and functional divergence within Metarhizium could be traced. Using M. brunneum as a model species, both BTPSLs and typical fungal TPSs were demonstrated to be involved in the in vivo production of terpenoids, illustrating the general importance of HGT of TPS genes from bacteria as a mechanism contributing to terpenoid diversity in fungi.