Requirement of a Mitogen-Activated Protein Kinase for Appressorium Formation and Penetration of Insect Cuticle by the Entomopathogenic Fungus Beauveria bassiana
Requirement of a Mitogen-Activated Protein Kinase for Appressorium Formation and Penetration of Insect Cuticle by the Entomopathogenic Fungus Beauveria bassiana
复制标题
昆虫病原真菌白僵菌附着胞形成和昆虫角质层渗透所需的丝裂原激活蛋白激酶
DOI：
10.1128/aem.02246-09
复制
发表时间：
2010-02
影响因子：
4.4
通讯作者：
张永军
中科院分区：
文献类型：
--
作者：
张永军
摘要球孢白僵菌是一种重要的昆虫病原真菌，它通过直接侵入寄主表皮而侵入昆虫体内。为了阐明真菌感染的分子机制，分离并鉴定了丝裂原活化蛋白激酶（MAPK）基因Bbmpk 1，其编码YERK1家族MAPK。Bbmpk1的靶向基因破坏导致局部应用于宿主昆虫时毒力完全丧失，但当分生孢子直接注射到血腔中时并不影响真菌的生长。在昆虫血腔中生长的突变菌株的菌丝不能穿透向外生长的角质层，因此不能在尸体表面形成孢子。这些数据表明，BbMPK 1是必不可少的昆虫角质层从外面和从内到外的渗透，以逃离和分散从主机。BbMPK1的失活也导致真菌粘附昆虫表皮的显著降低，并消除了它们形成附着胞的能力。为了确定由BbMPK1调控的下游基因，产生了一个抑制性消减杂交（SSH）文库，比较附着胞形成过程中分离的突变体和野生型转录本。从SSH文库中筛选的31个基因被确定为在野生型菌株中表达，但在突变体中显著降低或不表达。10个基因与已知的蛋白质编码基因显示出高度或中度相似性，包括参与细胞表面疏水性、脂质代谢、微管动力学、线粒体电子传递、染色质重塑、转录、rRNA加工、小核仁RNA积累、醛氧化、翻译和可能的其他细胞过程的蛋白质。
ABSTRACT Beauveria bassiana is an important insect-pathogenic fungus that invades insects by direct penetration of the host cuticle. To delineate the molecular mechanisms involved in fungal infection, a mitogen-activated protein kinase (MAPK) gene, Bbmpk1, which encodes a YERK1 family MAPK was isolated and characterized. Targeted gene disruption of Bbmpk1 resulted in a complete loss of virulence when applied topically to host insects but did not affect growth of the fungus when conidia were injected directly into the hemocoel. Hyphae of the mutant strain growing in the insect hemocoel were unable to penetrate the cuticle growing outwards and consequently failed to sporulate on the cadaver surface. These data suggest that BbMPK1 is essential for penetration of the insect cuticle both from the outside and from the inside-out in order to escape and disperse from the host. Inactivation of BbMPK1 also caused a significant decrease in fungal adhesion to insect cuticles and eliminated their ability to form appressoria. In order to identify downstream genes regulated by BbMPK1, a suppressive subtractive hybridization (SSH) library was generated comparing mutant and wild-type transcripts isolated during appressorium formation. Thirty-one genes screened from the SSH library were determined to be expressed in the wild-type strain but either significantly reduced or not expressed in the mutant. Ten genes showed high or medium similarity to known protein encoding genes, including proteins involved in cell surface hydrophobicity, lipid metabolism, microtubule dynamics, mitochondrial electron transport, chromatin remodeling, transcription, rRNA processing, small nucleolar RNA accumulation, oxidation of aldehydes, translation, and likely other cellular processes.
登录
查看更多内容
影响因子：
3.4
作者：
BIDOCHKA, MJ;KHACHATOURIANS, GG
通讯作者：
KHACHATOURIANS, GG
影响因子：
2.8
作者：
Holder, Diane J.;Kirkland, Brett H.;Keyhani, Nemat O.
通讯作者：
Keyhani, Nemat O.
影响因子：
4.4
作者：
Holder, DJ;Keyhani, NO
通讯作者：
Keyhani, NO
DOI：
10.1094/mpmi.2000.13.7.724
发表时间：
2000-07
期刊：
Molecular plant-microbe interactions : MPMI
影响因子：
--
作者：
Li Zheng;Mathew Campbell;J. Murphy;Stephen Lam;Jin-Rong Xu
通讯作者：
Li Zheng;Mathew Campbell;J. Murphy;Stephen Lam;Jin-Rong Xu
影响因子：
4.8
作者：
Li, YW;Kelly, WG;Kahn, RA
通讯作者：
Kahn, RA