Screening of plant signlas inducing hrp reguon in Ralstonia solanacearum

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07667
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant protection science
• Research Institution: Kochi University
• Principal Investigator: Ohnishi Kouhei 高知大学, 教育研究部総合科学系生命環境医学部門, 教授 (50211800)
• Co-Investigator(Kenkyū-buntansha): 木場 章範 高知大学, 教育研究部総合科学系生命環境医学部門, 教授 (50343314) ; 曵地 康史 高知大学, 教育研究部総合科学系生命環境医学部門, 教授 (70291507)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 植物シグナル / レポーター株 / GFP / LacZ / 静止菌体

Outline of Final Research Achievements

Genes encoding the type 3 secretion system and the type 3 effector, which are the major virulence factors of bacterial wilt disease in Ralstonia solanacarum, are subjected to unified expression regulation as a hrp regulon. The master operon of the hrp regulon is hrpB, and hrpB gene expression occurs only in planta. The purpose of this study is to search for plant signals that induce hrpB gene expression. In the process, we revealed phosphorylation of the response regulator HrpG, which is a two-component regulatory system upstream of hrpB, for the first time, and identified the candidates of corresponding sensor kinases. Moreover, by constructing and using the hrpB-lacZ reporter strain, it was possible to establish a route to search for plant signals that induce hrpB expression.

Free Research Field

微生物分子遺伝学

Academic Significance and Societal Importance of the Research Achievements

青枯病菌は、主要な栽培作物を始め、２００種類以上の宿主植物に感染し、委ちょう症状を引き起こす難防除病害菌である。青枯病菌の感染時に特異的に働くhrpレギュロンを抑制することができれば、完全に防除が可能である。本研究は、にhrpレギュロンを誘導する植物シグナルのアンタゴニストの開発につながり社会的意義は大きい。