A regulator of a G protein signalling (RGS) gene, cag8, from the insect-pathogenic fungus Metarhizium anisopliae is involved in conidiation, virulence and hydrophobin synthesis
A regulator of a G protein signalling (RGS) gene, cag8, from the insect-pathogenic fungus Metarhizium anisopliae is involved in conidiation, virulence and hydrophobin synthesis
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来自昆虫病原真菌金龟子绿僵菌的 G 蛋白信号 (RGS) 基因 cag8 的调节因子参与分生孢子形成、毒力和疏水蛋白合成
DOI：
10.1099/mic.0.2006/002105-0
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发表时间：
2007-04-01
期刊：
影响因子：
2.8
通讯作者：
Bidochka, Michael J.
中科院分区：
文献类型：
--
作者：
Fang, Weiguo;Pei, Yan;Bidochka, Michael J.
G蛋白信号传导（RGS）途径的调节因子参与控制多种细胞功能，包括丝状真菌的分生孢子形成。然而，在昆虫病原真菌分生孢子的调控过程中所涉及的知之甚少。由于分生孢子是这些真菌中的感染性繁殖体，因此了解分生孢子形成的调控过程对于开发有效的生防真菌至关重要。在这里，RGS蛋白基因，cag8（分生孢子相关基因），从昆虫病原真菌金龟子绿僵菌的克隆和鉴定的报告。系统进化分析表明，CAG 8与构巢曲霉RGS蛋白FlbA同源。A. nidulans Delta flbA，不能分生孢子，与M.绿僵菌cag8恢复产孢。在M.金龟子绿僵菌导致琼脂平板上和感染的昆虫上缺乏分生孢子，菌丝生长减少，毒力降低，在液体培养基中生长期间溶解，以及缺乏色素沉着和不规则形状的芽生孢子。在Delta cag8菌株中，ssgA（疏水蛋白编码基因）的转录水平显著降低，而pr1A（枯草杆菌蛋白酶样蛋白酶）转录不受影响。这些结果表明，cag8参与了M.绿僵菌
Regulators of the G protein signalling (RGS) pathway have been implicated in the control of a diverse array of cellular functions, including conidiation in filamentous fungi. However, the regulatory processes involved in conidiation in insect-pathogenic fungi are poorly understood. Since conidia are the infective propagules in these fungi, an understanding of the regulatory processes involved in conidiation is essential to the development of an effective biocontrol fungus. Here, the cloning and characterization of an RGS protein gene, cag8 (conidiation-associated gene), from the insect-pathogenic fungus Metarhizium anisopliae is reported. Phylogenetic analysis showed that CAG8 was orthologous to the RGS protein FlbA from Aspergillus nidulans. Complementation of A. nidulans Delta flbA, which cannot conidiate, with M. anisopliae cag8 restored conidiation. Gene disruption of cag8 in M. anisopliae resulted in the lack of conidia on agar plates and on infected insects, reduced mycelial growth, decreased virulence, lysis during growth in liquid medium as well as lack of pigmentation and irregularly shaped blastospores. Transcript levels of ssgA (hydrophobin-encoding gene) were markedly reduced in a Delta cag8 strain, while pr1A (subtilisin-like protease) transcription was unaffected. These results suggest that cag8 is involved in the modulation of conidiation, virulence and hydrophobin synthesis in M. anisopliae.