Identification of pathogenicity genes regulated by two kinds of transcription regulators of the fungal plant pathogen Fusarium oxysporum

植物病原菌尖孢镰刀菌两种转录调控子致病基因的鉴定

基本信息

批准号：
15208005
负责人：
TSUGE Takashi
金额：
$ 33.03万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

项目摘要

We previously identified two genes, FOW2 and FOW3, which encode Zn(II)2Cys6-type and His2Cys2-type transcription regulators, respectively, essential for plant infection in the melon wilt pathogen Fusarium oxysporum f. sp. melonis. In this research, we attempted to isolate Fow2-or Fow3-regulated genes.We constructed cDNA subtraction libraries, which contained genes with changes in transcription levels caused by mutations in FOW2 and FOW3. Screening of these libraries by cDNA dot-blot differential hybridization and RNA gel blot analyses identified six genes positively regulated by Fow2. We made mutants of these genes and identified a Ren1-regulated pathogenicity gene, named VRF2-1. The vrf2-1 mutant showed reduced virulence on melon plants, although the fow2 mutant completely lost pathogenicity. This result indicates that Fow2 regulates the transcription of multiple pathogenicity genes, including VRF2-1. We sequenced a BAC clone encoding FOW2 and found that VRF2-1 is also encoded by this … More clone. This clone contains additional 29 genes, of which 10 were found to be possibly regulated by Ren1, suggesting that the Fow2-regulated genes are closely linked with FOW2. Database homology search and PCR analysis revealed that the filamentous ascomycetes species have the FOW2 homologues. This suggests that the FOW2 homologues also control plant infection in other fungi.We also identified two genes, REN1 and FoSTUA, which encode different types of transcription regulators essential for conidiation in F. oxysporum. In plant pathogenic fungi, conidia play important roles in the disease cycle as disseminated propagules and primary and secondary inocula. We performed expressed sequence tag analysis during vegetative growth and conidiation and identified 496 genes specifically detected in the conidiation cDNA library. Comparison of the transcription levels of the 496 genes between the wild-type strain and the ren1 mutant or the fostuA mutant identified 35 and three genes regulated by Ren1 and FoStuA, respectively. Less

我们先前鉴定了两个基因FOW2和FOW3，它们分别编码Zn（ii）2Cys6型和HIS2CYS2型转录调节剂，对于瓜质病原体oxysporum f中的植物感染至关重要。 sp。瓜。在这项研究中，我们试图隔离FOW2-或FOW3调节的基因。我们构建了cDNA减法文库，其中包含由FOW2和FOW3突变引起的转录水平变化的基因。通过cDNA点印刷差异杂交和RNA凝胶印迹分析对这些文库进行筛选，确定了六个由FOW2阳性调节的基因。我们制作了这些基因的突变体，并鉴定出一个被REN1调节的致病性基因，称为VRF2-1。尽管FOW2突变体完全失去致病性，但VRF2-1突变体显示瓜植物的病毒降低。该结果表明FOW2调节了包括VRF2-1在内的多个致病性基因的转录。我们对一个编码FOW2的BAC克隆进行了测序，发现VRF2-1也被此……更多的克隆编码。该克隆包含另外的29个基因，其中10个可能受Ren1调节，这表明FOW2调节的基因与FOW2紧密相关。数据库同源性搜索和PCR分析表明，丝状comcycetes物种具有FOW2同源物。这表明FOW2同源物还控制着其他真菌中的植物感染。我们还确定了两个基因Ren1和Fostua，它们编码了F. oxysporum在F. oxysporum中所必需的不同类型的转录调节剂。在植物致病真菌中，分生孢子在疾病周期中起着重要作用，作为散布的繁殖体以及原发性和继发接种。我们在蔬菜生长和分生过程中进行了表达的序列标签分析，并鉴定出在分量cDNA文库中特异性检测到的496个基因。比较野生型菌株与Ren1突变体或Fostua突变体之间496个基因的转录水平分别鉴定出由Ren1和Fostua调节的35个基因。较少的