A Nitrogen Response Pathway Regulates Virulence Functions in Fusarium oxysporum via the Protein Kinase TOR and the bZIP Protein MeaB
A Nitrogen Response Pathway Regulates Virulence Functions in Fusarium oxysporum via the Protein Kinase TOR and the bZIP Protein MeaB
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DOI：
10.1105/tpc.110.075937
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发表时间：
2010-07-01
期刊：
影响因子：
11.6
通讯作者：
Di Pietro, Antonio
中科院分区：
文献类型：
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作者：
Lopez-Berges, Manuel S.;Rispail, Nicolas;Di Pietro, Antonio
在感染过程中，真菌病原体激活毒力机制，如宿主粘附，渗透和侵入性生长。在维管枯萎病真菌尖孢镰刀菌中，有丝分裂原活化蛋白激酶Fmk 1是植物感染和控制过程所必需的，如玻璃纸渗透、营养菌丝融合或根粘附。在这里，我们表明，这些毒力相关的功能被抑制的首选氮源铵和恢复治疗与L-甲硫氨酸亚砜亚胺或雷帕霉素，两个特定的抑制剂谷氨酰胺合成酶和蛋白激酶TOR，分别。bZIP蛋白MeaB的缺失也导致了毒力机制的氮源非依赖性激活。这些功能的激活并不需要全局氮调节剂AreA，这表明MeaB介导的毒力功能抑制不通过抑制AreA起作用。番茄植株（番茄）提供铵，而不是硝酸盐表现出显着减少血管枯萎病的症状时，感染野生型，但不与三角洲meaB菌株。氮源也影响稻瘟病菌和小麦赤霉病菌的入侵生长。我们提出，保守的氮响应途径可能通过TOR和MeaB来控制植物病原真菌的毒力。
During infection, fungal pathogens activate virulence mechanisms, such as host adhesion, penetration and invasive growth. In the vascular wilt fungus Fusarium oxysporum, the mitogen-activated protein kinase Fmk1 is required for plant infection and controls processes such as cellophane penetration, vegetative hyphal fusion, or root adhesion. Here, we show that these virulence-related functions are repressed by the preferred nitrogen source ammonium and restored by treatment with L-methionine sulfoximine or rapamycin, two specific inhibitors of Gln synthetase and the protein kinase TOR, respectively. Deletion of the bZIP protein MeaB also resulted in nitrogen source-independent activation of virulence mechanisms. Activation of these functions did not require the global nitrogen regulator AreA, suggesting that MeaB-mediated repression of virulence functions does not act through inhibition of AreA. Tomato plants (Solanum lycopersicum) supplied with ammonium rather than nitrate showed a significant reduction in vascular wilt symptoms when infected with the wild type but not with the Delta meaB strain. Nitrogen source also affected invasive growth in the rice blast fungus Magnaporthe oryzae and the wheat head blight pathogen Fusarium graminearum. We propose that a conserved nitrogen-responsive pathway might operate via TOR and MeaB to control virulence in plant pathogenic fungi.