The adenylate cyclase gene MAC1 of Magnaporthe grisea controls Appressorium formation and other aspects of growth and development
The adenylate cyclase gene MAC1 of Magnaporthe grisea controls Appressorium formation and other aspects of growth and development
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DOI：
10.1105/tpc.9.11.1973
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发表时间：
1997-11-01
期刊：
影响因子：
11.6
通讯作者：
Dean, RA
中科院分区：
文献类型：
--
作者：
Choi, WB;Dean, RA
稻瘟病菌是引起稻瘟病的病原菌，它分化出一种称为附着胞的特殊感染结构，这种结构对寄主植物的侵入至关重要。以前，人们发现cAMP调节附着胞的形成。为了进一步了解附着胞形成的细胞机制，我们克隆了一个基因（MAC 1）编码腺苷酸环化酶，膜结合酶，催化生产cAMP从ATP，通过使用聚合酶链反应为基础的策略。从大型插入细菌人工染色体文库中分离并亚克隆了整个基因。序列分析表明，MAC 1与其他几种丝状真菌以及酵母的腺苷酸环化酶基因具有高度的同一性。基因缺失导致营养生长、分生孢子形成和分生孢子萌发减少。缺乏MAC 1的转化体不能在诱导表面形成附着胞，也不能穿透感病水稻叶片。Mac 1（-）转化体也是不育的，不产生周皮。附着胞的形成恢复在外源性cAMP衍生物的存在下。这些结果证实了涉及cAMP的细胞信号传导在M.灰色的。
Magnaporthe grisea, the causal agent of rice blast disease, differentiates a specialized infection structure called an appressorium that is crucial for host plant penetration. Previously, it was found that cAMP regulates appressorium formation. To further understand the cellular mechanisms involved in appressorium formation, we have cloned a gene (MAC1) encoding adenylate cyclase, a membrane-bound enzyme that catalyzes the production of cAMP from ATP, by using a polymerase chain reaction-based strategy. The entire gene was isolated and subcloned from a large insert bacterial artificial chromosome library. Sequence characterization showed that MAC1 has a high degree of identity with other adenylate cyclase genes from several filamentous fungi as well as yeasts. Gene deletion resulted in reduced vegetative growth, conidiation, and conidial germination. Transformants lacking MAC1 were unable to form appressoria on an inductive surface and were unable to penetrate susceptible rice leaves. mac1(-) transformants were also sterile and produced no perithecia. Appressorium formation was restored in the presence of exogenous cAMP derivatives. These results confirm that cell signaling involving cAMP plays a central role in the development and pathogenicity of M. grisea.