{"title":"Mr-lac3 and Mr-lcc2 in <i>Metarhizium robertsii</i> Regulate Conidiation and Maturation, Enhancing Tolerance to Abiotic Stresses and Pathogenicity.","authors":"Qiaoyun Wu, Yingying Ye, Yiran Liu, Yufan He, Xing Li, Siqi Yang, Tongtong Xu, Xiufang Hu, Guohong Zeng","doi":"10.3390/jof11030176","DOIUrl":null,"url":null,"abstract":"<p><p>As a type of multicopper oxidase, laccases play multiple biological roles in entomopathogenic fungi, enhancing their survival, development, and pathogenicity. However, the mechanisms by which laccases operate in these fungi remain under-researched. In this study, we identified two laccase-encoding genes, <i>Mr-lac3</i> and <i>Mr-lcc2</i>, from <i>Metarhizium robertsii</i>, both of which are highly expressed during conidiation. Knocking out <i>Mr-lac3</i> and <i>Mr-lcc2</i> resulted in a significant increase in the conidial yields of <i>M. robertsii</i>. Furthermore, the relative expression levels of upstream regulators associated with the conidiation pathway were markedly up-regulated in <i>ΔMr-lac3</i> and <i>ΔMr-lcc2</i> compared to the wild-type strain during conidiation, indicating that <i>Mr-lac3</i> and <i>Mr-lcc2</i> negatively regulate conidia formation. qRT-PCR analyses revealed that <i>Mr-lac3</i> and <i>Mr-lcc2</i> are regulated by the pigment synthesis gene cluster, including <i>Mr-Pks1</i>, <i>Mr-EthD</i>, and <i>Mlac1</i>, and they also provide feedback regulation to jointly control pigment synthesis. Additionally, <i>ΔMr-lac3</i> and <i>ΔMr-lcc2</i> significantly reduced the trehalose content in conidia and increased the sensitivity to cell wall-perturbing agents, such as Congo red and guaiacol, which led to a marked decrease in tolerance to abiotic stresses. In conclusion, the laccases Mr-lac3 and Mr-lcc2 negatively regulate conidia formation while positively regulating conidial maturation, thereby enhancing tolerance to abiotic stresses and pathogenicity.</p>","PeriodicalId":15878,"journal":{"name":"Journal of Fungi","volume":"11 3","pages":""},"PeriodicalIF":4.2000,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11942773/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Fungi","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.3390/jof11030176","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
As a type of multicopper oxidase, laccases play multiple biological roles in entomopathogenic fungi, enhancing their survival, development, and pathogenicity. However, the mechanisms by which laccases operate in these fungi remain under-researched. In this study, we identified two laccase-encoding genes, Mr-lac3 and Mr-lcc2, from Metarhizium robertsii, both of which are highly expressed during conidiation. Knocking out Mr-lac3 and Mr-lcc2 resulted in a significant increase in the conidial yields of M. robertsii. Furthermore, the relative expression levels of upstream regulators associated with the conidiation pathway were markedly up-regulated in ΔMr-lac3 and ΔMr-lcc2 compared to the wild-type strain during conidiation, indicating that Mr-lac3 and Mr-lcc2 negatively regulate conidia formation. qRT-PCR analyses revealed that Mr-lac3 and Mr-lcc2 are regulated by the pigment synthesis gene cluster, including Mr-Pks1, Mr-EthD, and Mlac1, and they also provide feedback regulation to jointly control pigment synthesis. Additionally, ΔMr-lac3 and ΔMr-lcc2 significantly reduced the trehalose content in conidia and increased the sensitivity to cell wall-perturbing agents, such as Congo red and guaiacol, which led to a marked decrease in tolerance to abiotic stresses. In conclusion, the laccases Mr-lac3 and Mr-lcc2 negatively regulate conidia formation while positively regulating conidial maturation, thereby enhancing tolerance to abiotic stresses and pathogenicity.
期刊介绍:
Journal of Fungi (ISSN 2309-608X) is an international, peer-reviewed scientific open access journal that provides an advanced forum for studies related to pathogenic fungi, fungal biology, and all other aspects of fungal research. The journal publishes reviews, regular research papers, and communications in quarterly issues. Our aim is to encourage scientists to publish their experimental and theoretical results in as much detail as possible. Therefore, there is no restriction on paper length. Full experimental details must be provided so that the results can be reproduced.