Molecular analysis of pathogenicity of Fusarium oxysporum by gene tagging

通过基因标记对尖孢镰刀菌致病性进行分子分析

基本信息

批准号：
13460022
负责人：
TSUGE Takashi
金额：
$ 7.94万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13460022/
关键词：
plant pathogenic fungus Fusarium oxysporum pathogenicity gene REMI mutant arginine biosynthesis mitochondrial carrier transcription regulator PEP carboxykinase 胞子形成遺伝子

项目摘要

The soil-borne fungus Fusarium oxysporum causes vascular wilts of a wide variety of plant species by directly penetrating roots and colonizing the vascular tissue. Individual pathogenic strains within the species have a limited host range, and strains similar or identical host ranges are assigned to intraspecific groups, called formae speciales (f.sp.). We previously isolated 43 pathogenicity mutants of the melon wilt pathogen F.oxysporum f. sp. Melonis by restriction enzyme-mediated DNA integration mutagenesis. In this research, we analyzed the structures and functions of tagged sites in the mutants to isolate genes required for pathogenicity and symptom development by this pathogen.We identified the mutated genes, named AGR1, FOW1, FOW2, FOW3, and FOW4, from five mutants. Essential roles of these genes in full pathogenicity of this pathogen were confirmed by genetic complementation and transformation-mediated targeting experiments. These genes possibly encode argininosuccinate lyase, mitochondrial carrier protein, Zn(II)2Cys6 transcription factor, Cys2His2 transcription factor, and phosphoenoylpyruvate carboxykinase, respectively, and are novel pathogenicity genes of plant pathogenic fungi.FOW2 and FOW3 encode different transcription regulators, suggesting that they regulate expression of the genes directly involved in pathogenicity. In this research, we isolated a Fow2-regulated gene, named F2R1, by subtraction of cDNAs of the wild-type strain with those of the fow2 mutant. F2R1 encodes a protein similar to cytokine-regulated glycoprotein of the animal pathogen Cryptococcus neoformans. The f2r1 mutant showed slightly reduced virulence to melon plants, although the fow2 mutant completely lost pathogenicity. These results suggest that Fow2 regulates expression of multiple pathogenicity genes, including F2R1.

土传真菌尖孢镰刀菌直接穿透根部并在维管组织中定植，引起多种植物的维管枯萎病。物种内的单个致病菌株具有有限的宿主范围，并且相似或相同宿主范围的菌株被分配到种内组，称为特殊型（f.sp.）。我们之前分离出了 43 个甜瓜枯萎病病原体尖孢镰刀菌 (F.oxysporum f.) 的致病性突变体。 sp。 Melonis 通过限制酶介导的 DNA 整合诱变。在本研究中，我们分析了突变体中标记位点的结构和功能，以分离该病原体致病性和症状发展所需的基因。我们从五个突变体中鉴定出突变基因，命名为AGR1、FOW1、FOW2、FOW3和FOW4 。通过遗传互补和转化介导的靶向实验证实了这些基因在该病原体的全部致病性中的重要作用。这些基因可能分别编码精氨琥珀酸裂合酶、线粒体载体蛋白、Zn(II)2Cys6转录因子、Cys2His2转录因子和磷酸烯酰丙酮酸羧激酶，是植物病原真菌的新型致病基因。FOW2和FOW3编码不同的转录调节因子，表明它们调节直接参与致病性的基因的表达。在这项研究中，我们通过将野生型菌株的 cDNA 与 fow2 突变体的 cDNA 相减，分离出一个 Fow2 调控基因，命名为 F2R1。 F2R1 编码一种与动物病原体新型隐球菌的细胞因子调节糖蛋白类似的蛋白质。 f2r1突变体对瓜类植物的毒力略有降低，但fow2突变体完全丧失了致病性。这些结果表明 Fow2 调节多种致病基因的表达，包括 F2R1。