Zhang Lvhao, Yang Tian, Yu Wangyin, Wang Xiaojun, Zhou Xiang, Zhou Xudong
State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, China.
J Fungi (Basel). 2022 Apr 12;8(4):389. doi: 10.3390/jof8040389.
Fungi in the Entomophthorales order can cause insect disease and epizootics in nature, contributing to biological pest control in agriculture and forestry. Most Entomophthorales have narrow host ranges, limited to the arthropod family level; however, rare genomic information about host-specific fungi has been reported. Conidiation is crucial for entomopathogenic fungi to explore insect resources owing to the important roles of conidia in the infection cycle, such as dispersal, adhesion, germination, and penetration into the host hemocoel. In this study, we analyzed the whole genome sequence of the aphid-obligate pathogen strain ARSEF 7217 (Entomophthoromycotina), using Nanopore technology from Biomarker Technologies (Beijing, China). The genome size was 37.6 Mb, and encoded 10,262 predicted genes, wherein 21.3% genes were putatively associated to the pathogen-host interaction. In particular, the serine protease repertoire in exhibited expansions in the trypsin and subtilisin classes, which play vital roles in the fungus' pathogenicity. Differentially expressed transcriptomic patterns were analyzed in three conidiation stages (pre-conidiation, emerging conidiation, and post-conidiation), and 2915 differentially expressed genes were found to be associated with the conidiation process. Furthermore, a weighted gene co-expression network analysis showed that 772 hub genes in conidiation are mainly involved in insect cuticular component degradation, cell wall/membrane biosynthesis, MAPK signaling pathway, and transcription regulation. Our findings of the genomic and transcriptomic features of help reveal the molecular mechanism of the Entomophthorales pathogenicity, which will contribute to improving fungal applications in pest control.
虫霉目真菌可在自然界引发昆虫疾病和流行病，有助于农林生物害虫防治。大多数虫霉目真菌宿主范围狭窄，仅限于节肢动物科级水平；然而，关于宿主特异性真菌的基因组信息报道较少。由于分生孢子在感染周期中具有重要作用，如传播、黏附、萌发以及穿透进入宿主体腔，因此分生孢子形成对于昆虫病原真菌利用昆虫资源至关重要。在本研究中，我们使用中国北京博奥晶典生物技术有限公司的纳米孔技术，分析了蚜虫专性病原菌菌株ARSEF 7217（虫霉亚纲）的全基因组序列。基因组大小为37.6 Mb，编码10262个预测基因，其中21.3%的基因可能与病原菌-宿主相互作用相关。特别是，该菌的丝氨酸蛋白酶家族在胰蛋白酶和枯草杆菌蛋白酶类别中出现了扩增，这些蛋白酶在真菌致病性中发挥着重要作用。我们分析了三个分生孢子形成阶段（分生孢子形成前、分生孢子形成初期和分生孢子形成后期）的差异表达转录组模式，发现2915个差异表达基因与分生孢子形成过程相关。此外，加权基因共表达网络分析表明，分生孢子形成过程中的772个枢纽基因主要参与昆虫表皮成分降解、细胞壁/细胞膜生物合成、丝裂原活化蛋白激酶信号通路和转录调控。我们对该菌基因组和转录组特征的研究结果有助于揭示虫霉目真菌致病性的分子机制，这将有助于改进真菌在害虫防治中的应用。
