Analysis on the resistance against plant viruses through the levels of endogenous ascorbic acid

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660031
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Plant protection science
• Research Institution: Hokkaido University
• Principal Investigator: MASUTA Chikara 北海道大学, (連合)農学研究科(研究院), 教授 (60281854)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: ビタミンC / RNAサイレンシング / ウイルス / Arabidopsis

Outline of Final Research Achievements

We demonstrated that endogenous ascorbic acid (AsA) was closely associated with an antiviral response to Turnip mosaic virus (TuMV) in Brassica rapa and Arabidopsis thaliana. The AsA accumulation was induced by TuMV infection in B. rapa cvs. Aki-masari and Ku-kai 65, that have the resistant gene Rnt1-1. They accumulated about 1.5-fold higher levels of AsA 3 days after inoculation of the avirulent TuMV (strain UK1). Our gene expression analysis suggested that the observed AsA increase was due to the suppression of AsA oxidation by ascorbate peroxidase (APX) and ascorbate oxidase (AO), and the activation of AsA-recycling by dehydroascorbate reductase (DHAR). Endogenously supplied JA and JA derivatives actually increased the endogenous level of AsA. We therefore reasoned that the induction of the AsA accumulation in Aki-masari may be mediated by the JA-dependent signaling pathway as a defense reaction against viruses.

Free Research Field

植物ウイルス学