title: Dicer and Argonaute Genes Involved in RNA Interference in the Entomopathogenic Fungus Metarhizium robertsii.
abstract: RNA interference (RNAi) is a gene-silencing mechanism that plays an important role in gene regulation in a number of eukaryotic organisms. Two core components, Dicer and Argonaute, are central in the RNAi machinery. However, the physiological roles of Dicer and Argonaute in the entomopathogenic fungusMetarhizium robertsiihave remained unclear. Here, the roles of genes encoding Dicer (M. robertsiidcl1[Mrdcl1] andMrdcl2) and Argonaute (Mrago1andMrago2) proteins inM. robertsiiwere investigated. The results showed that the Dicer-like protein MrDCL2 and Argonaute protein MrAGO1 are the major components of the RNAi process occurring inM. robertsiiThe Dicer and Argonaute genes were not involved in the regulation of growth and diverse abiotic stress response inM. robertsiiunder the tested conditions. Moreover, our results showed that the Dicer and Argonaute gene mutants demonstrated reduced abilities to produce conidia, compared to the wild type (WT) and the gene-rescued mutant. In particular, the conidial yields in the Δdcl2and Δago1mutants were reduced by 55.8% and 59.3%, respectively, compared with those from the control strains. Subsequently, for the WT and Δdcl2mutant strains, digital gene expression (DGE) profiling analysis of the stage of mycelium growth and conidiogenesis revealed that modest changes occur in development or metabolism processes, which may explain the reduction in conidiation in the Δdcl2mutant. In addition, we further applied high-throughput sequencing technology to identify small RNAs (sRNAs) that are differentially expressed in the WT and the Δdcl2mutant and found that 4 known microRNA-like small RNAs (milRNAs) and 8 novel milRNAs wereMrdcl2dependent inM. robertsiiIMPORTANCEThe identification and characterization of components in RNAi have contributed significantly to our understanding of the mechanism and functions of RNAi in eukaryotes. Here, we found that Dicer and Argonaute genes play an important role in regulating conidiation inM. robertsiiOur study also demonstrates that diverse small RNA pathways exist inM. robertsiiThe study provides a theoretical platform for exploration of the functions of Dicer and Argonaute genes involved in RNAi in fungi.
authors.affiliation: Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China.|Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Meng
authors.affiliation: Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China.|School of Plant Protection, Anhui Agricultural University, Hefei, China.
authors.forename: Zhangxun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China bhuang@ahau.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
mesh_terms: D060565:Argonaute Proteins / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D059014:High-Throughput Nucleotide Sequencing; D052981:Metarhizium / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D009154:Mutation; D025282:Mycelium / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000302:isolation & purification; D043244:Ribonuclease III / Q000235:genetics* / Q000378:metabolism; D013172:Spores, Fungal / Q000254:growth & development
chemical_list: D060565:Argonaute Proteins; D005656:Fungal Proteins; D034741:RNA, Small Interfering; D043244:Ribonuclease III
keywords: Argonaute; Dicer; Metarhizium robertsii; RNA interference