Study on the function of individual type III effectors of Ralstonis pseudosolanacearum using a super-multi deletion mutant

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06054
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39040:Plant protection science-related
• 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): 2020-04-01 – 2023-03-31
• Keywords: ３型エフェクター / 青枯病菌 / ナス / タバコ

Outline of Final Research Achievements

An OE1-1D50E, which lacked 50 type 3 effectors (T3E) from Ralstonia pseudosolanacearum OE1-1, lost pathogenicity and was considered an effectorless strain. Twenty-one 1T3E-expressing strains were constructed based on this strain. None of the strains were pathogenic to tobacco. No cell proliferation was observed in eggplant and tobacco leaves, but some strains showed an HR-like phenotype with a decrease in cell number at 4 dpi. Eggplant and tobacco leaves were also inoculated with T3E-expressing strains, and ion leakage, a cell death phenotype, was examined. A ripA5 expressing-strain induced cell death. Furthermore, the expression of HR-related genes was upregulated in OE1-1D50E infiltrated leaves, whereas it was downregulated in the leaves infiltrated by most T3E-expressing strains.

Free Research Field

微生物分子遺伝学

Academic Significance and Societal Importance of the Research Achievements

青枯病菌は数多くの宿主に感染する難防除病害菌である。宿主との感染におけるせめぎあいの中で、多くの３型エフェクター（T3E）を蓄積してきた。その中には機能が重複するものもあり、個々のT3Eの機能がわかりづらくなっている。本研究の研究成果により各T3Eの機能が明確化されることで、T3E機能の体系化が可能となる。また、その結果新たな防除技術の開発の可能性を開くという社会的意義が見いだされる。