In Vivo Study of the Sorbicillinoid Gene Cluster in Trichoderma reesei.
In Vivo Study of the Sorbicillinoid Gene Cluster in Trichoderma reesei.
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DOI：
10.3389/fmicb.2017.02037
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发表时间：
2017
影响因子：
5.2
通讯作者：
Mach-Aigner AR
中科院分区：
文献类型：
--
作者：
Derntl C;Guzmán-Chávez F;Mello-de-Sousa TM;Busse HJ;Driessen AJM;Mach RL;Mach-Aigner AR
索比西林类化合物是一组不同的黄色次级代谢产物，由一系列不密切相关的子囊菌产生，包括产黄青霉、产黄枝顶孢霉和里氏木霉。它们与命名化合物山梨西林（一种六酮化合物）有相似之处。以前，一个包含两个聚酮酶的保守基因簇已被确定为山梨西林的来源，并提出了产黄青霉中山梨西林生物合成的模型。在这项研究中，我们删除了T. reesei，即sor 1、sor 3和sor 4。Sor 1是P. chrysogenum索拉A的同源物，而索拉A是该生物合成途径的第一个聚酮合酶。Sor 3是一种黄素腺嘌呤二核苷酸（FAD）依赖的单加氧酶，其同源物SorC在体外可将山梨西林和2′，3 ′-二氢山梨西林分别氧化为山梨西林醇和2 ′，3 ′-二氢山梨西林醇。Sor 4是一种功能未知的FAD/黄素单核苷酸脱氢酶。我们测量了在整个生长过程中合成的索比西林类化合物的量，并可以验证Sor 1和Sor 3在T. reesei。在Sor 4不存在的情况下，注释为二氢山梨西林醇的两种化合物在上清液中积累，并且仅合成少量的山梨西林醇。因此，我们建议将目前Sor 4还原2′，3 ′-二氢山梨西林和2′，3 ′-二氢山梨西林醇的生物合成模型分别扩展为山梨西林醇和山梨西林醇。山梨西林醇被证明是大多数山梨西林类化合物的主要化学结构单元，包括氧代山梨西林醇、双山梨西林醇和双维替隆。此外，我们在早期时间点检测到5-羟基维替尼的山梨西林依赖性合成，这与之前的5-羟基维替尼生物合成模型相矛盾。最后，我们研究了T.里氏木霉对真菌本身或植物病原真菌或病原细菌具有生长限制作用。
Sorbicillinoids are a diverse group of yellow secondary metabolites that are produced by a range of not closely related ascomycetes, including Penicillium chrysogenum, Acremonium chrysogenum, and Trichoderma reesei. They share a similarity to the name-giving compound sorbicillin, a hexaketide. Previously, a conserved gene cluster containing two polyketide synthases has been identified as the source of sorbicillin, and a model for the biosynthesis of sorbicillin in P. chrysogenum has been proposed. In this study, we deleted the major genes of interest of the cluster in T. reesei, namely sor1, sor3, and sor4. Sor1 is the homolog of P. chrysogenum SorA, which is the first polyketide synthase of the proposed biosynthesis pathway. Sor3 is a flavin adenine dinucleotide (FAD)-dependent monooxygenase, and its homolog in P. chrysogenum, SorC, was shown to oxidize sorbicillin and 2′,3′-dihydrosorbicillin to sorbicillinol and 2′,3′-dihydrosorbicillinol, respectively, in vitro. Sor4 is an FAD/flavin mononucleotide-containing dehydrogenase with an unknown function. We measured the amounts of synthesized sorbicillinoids throughout growth and could verify the roles of Sor1 and Sor3 in vivo in T. reesei. In the absence of Sor4, two compounds annotated to dihydrosorbicillinol accumulate in the supernatant and only small amounts of sorbicillinol are synthesized. Therefore, we suggest extending the current biosynthesis model about Sor4 reducing 2′,3′-dihydrosorbicillin and 2′,3′-dihydrosorbicillinol to sorbicillinol and sorbicillinol, respectively. Sorbicillinol turned out to be the main chemical building block for most sorbicillinoids, including oxosorbicillinol, bisorbicillinol, and bisvertinolon. Further, we detected the sorbicillinol-dependent synthesis of 5-hydroxyvertinolide at early time points, which contradicts previous models for biosynthesis of 5-hydroxyvertinolide. Finally, we investigated whether sorbicillinoids from T. reesei have a growth limiting effect on the fungus itself or on plant pathogenic fungi or on pathogenic bacteria.