Mild Pathogenic Bacteria ; virulence and compatibility against plants

轻度致病菌；

基本信息

批准号：
13660045
负责人：
TAKIKAWA Yuichi
金额：
$ 2.37万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13660045/
关键词：
Burkholderia cepacia Herbaspirillum Pseudomonas fuscovaginae hip genes fliC gene pectinase plant pathogenic bacteria hrc遺伝子 Herbaspirillum sp.過敏感反応

项目摘要

In this study, "Mild Pathogenic Bacteria" isolated from various plants including onions, turf grasses and strawberries were identified as Burkholderia cepacia, Pseudomonas fuscovaginae and Herbaspirillum sp., respectively. B. cepacia strains were divided into two groups, i.e. genomovar (gv.) I and III. Most of gv. I strains did not have hrp genes whereas gv. III strains did, despite of negative HR induction on tobacco by all the strains. Their genetic backgrounds were diverse and did not correspond to pathogenicity. Only the presence of pectate lyase gene corresponded to maceration activity of the bacteria on onion slice.P. fuscovaginae strains also were shown to lack the hrp genes, though they showed HR-like reaction on tobacco plants. This reaction was considered to be caused by novel pectate lyase strongly induced in planta and possibly by flagella. These observation suggested that the hrp gene is not the sole key-point genetic factor for the pathogenicity of Mild Pathogenic Bacterium. This new idea contradicts the well-established concepts for virulence of typical plant pathogenic bacteria.In case for Herbaspirillum strains, hrp genes could be detected despite that some strains were HR-negative. Genetic library was constructed and a cosmid clone containing hrp gene was successfully screened. From the sequences of the clone, hrcV and hrcN genes were identified, which resembled to those of other β-Proteobacteria but could be allocated to a new isolated position in the course of evolution. Therefore, this group of bacteria could be positioned as a new group in plant pathogen.

在这项研究中，分别从包括洋葱，草皮草和草莓在内的各种植物中分离出来的“轻度致病细菌”分别为Burkholderia cepacia，fuscovaginae和Herbaspirillum sp。。 B. cepacia菌株分为两组，即Genomovar（Gv。）I和III。大部分GV。我菌株没有HRP基因，而GV。尽管所有菌株对烟草的HR诱导负阴性，但III菌株确实确实。他们的遗传背景是潜水员，并不对应于致病性。只有果胶裂解酶基因的存在与细菌在洋葱切片上的浸渍活性相对应。 Fuscovaginae菌株也证明缺乏HRP基因，尽管它们在烟草植物上表现出类似HR样的反应。该反应被认为是由植物中强烈诱导的新型果胶裂解酶引起的，并由鞭毛引起的。这些观察结果表明，HRP基因不是轻度致病细菌致病性的唯一关键点遗传因子。这个新想法与典型植物致病细菌病毒的良好概念相矛盾。在赫巴斯螺旋菌株的情况下，可以检测到HRP基因的某些菌株是HR-HR阴性。构建了遗传文库，并成功筛选了一个含有HRP基因的宇宙克隆。从克隆的序列，HRCV和HRCN基因的序列中，它们类似于其他β-蛋白杆菌的基因，但可以分配给新的孤立位置。因此，这组细菌可以定位为植物病原体中的新组。