Transducin Beta-Like Gene FTL1 Is Essential for Pathogenesis in Fusarium graminearum
Transducin Beta-Like Gene FTL1 Is Essential for Pathogenesis in Fusarium graminearum
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DOI：
10.1128/ec.00048-09
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发表时间：
2009-06-01
期刊：
影响因子：
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通讯作者：
Xu, Jin-Rong
中科院分区：
文献类型：
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作者：
Ding, Shengli;Mehrabi, Rahim;Xu, Jin-Rong
小麦赤霉病（Fusarium graminearum）是小麦和大麦的重要病害。在之前的研究中，我们通过插入诱变发现了几种毒力降低的突变体。在其中一种非致病性突变体中，名为FTL1的转导蛋白样基因被破坏。FTL1与酿酒酵母SIF2同源，后者是Set3复合体的一个组成部分，参与子囊孢子形成的后期。Delta ft1突变体在分生条件下显著减少，不能引起典型的疾病症状。它不能在接种小麦穗轴的维管组织中定植，也不能引起穗轴坏死。Delta fft1突变体在从感染的花药向子房传播方面也存在缺陷，并且比野生型对植物防御素MsDef1和渗透素更敏感。然而，两种丝裂原激活蛋白激酶Mgv1和Gpmk1的激活、脱氧雪腐镰刀菌醇的产生以及已知对植物侵染重要的基因的表达均未受到影响，这表明Delta ftl1突变体在植物侵染中的缺陷与该病原体已知的毒力因素无关，可能涉及新的机制。Delta ftl1缺失突变体的组蛋白去乙酰化显著降低，酵母Set3复合体的许多成员在F. graminearum中被保守。FTL1似乎是这种保守蛋白复合物的一个组成部分，在小麦组织的渗透和定植中起着关键作用。
Fusarium head blight caused by Fusarium graminearum is an important disease of wheat and barley. In a previous study, we identified several mutants with reduced virulence by insertional mutagenesis. A transducin beta-like gene named FTL1 was disrupted in one of these nonpathogenic mutants. FTL1 is homologous to Saccharomyces cerevisiae SIF2, which is a component of the Set3 complex involved in late stages of ascospore formation. The Delta ftl1 mutant was significantly reduced in conidiation and failed to cause typical disease symptoms. It failed to colonize the vascular tissues of rachis or cause necrosis on the rachis of inoculated wheat heads. The Delta ftl1 mutant also was defective in spreading from infected anthers to ovaries and more sensitive than the wild type to plant defensins MsDef1 and osmotin. However, the activation of two mitogen-activated protein kinases, Mgv1 and Gpmk1, production of deoxynivalenol, and expression of genes known to be important for plant infection in F. graminearum were not affected, indicating that the defect of the Delta ftl1 mutant in plant infection is unrelated to known virulence factors in this pathogen and may involve novel mechanisms. The Delta ftl1 deletion mutant was significantly reduced in histone deacetylation, and many members of the yeast Set3 complex are conserved in F. graminearum. FTL1 appears to be a component of this well-conserved protein complex that plays a critical role in the penetration and colonization of wheat tissues.