A cradle of pandemic plant viruses: mechanisms underlying host jump from perennial weeds to agricultural crops.

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06048
• 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: Tokyo University of Agriculture and Technology
• Principal Investigator: Komatsu Ken 東京農工大学, (連合)農学研究科(研究院), 准教授 (60451837)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 植物ウイルス / ポテックスウイルス / オオバコ / ユリ / 多年生野草 / 系統解析 / 集団遺伝学的解析 / 適応進化

Outline of Final Research Achievements

Plantago asiatica mosaic virus (PlAMV), a member of the genus Potexvirus, infects ornamental lilies and causes severe necrotic symptoms. Phylogenetic analysis using the full-length genome sequences of all available 36 isolates, including 14 new isolates in Japan, revealed that PlAMV isolates were divided into five clades, one Lily Clade and four clades (Clade I to Clade IV) that included isolates from weeds, which are differentiated depending on host and geographical location. PlAMV isolates in different phylogenetic clades infected a subset of plant species differently. Especially, only isolates from Clade III, which includes several isolates from P. asiatica, can infect this host. All PlAMV isolates from weed plants cannot infect ornamental lilies. Analysis of a site-specific positive selection has identified a total of 20 sites under episodic diversifying selection, which are concentrated in replicase- and coat protein-encoding regions.

Free Research Field

植物ウイルス学

Academic Significance and Societal Importance of the Research Achievements

本研究はオオバコという誰にとっても身近な多年生野草に感染しているPlAMVというウイルスが、日本国内だけでも大きく２つの集団に分かれていることを示すとともに、これらのユリへの感染が難しいことを示した。このことは、鑑賞ユリに被害を及ぼしている本ウイルスの一群は一度だけ進化し、ユリに特殊に適応したものであることを示しており、検疫上問題となっている本ウイルスの性状把握に重要な知見を提供するものである。