Journal of General Plant Pathology (2013) 79, 198-204

Ayaka Fujiwara, Hanako Shimura, Chikara Masuta, Shinsuke Sano and Tsuyoshi Inukai (2013)
Exogenous ascorbic acid derivatives and dehydroascorbic acid are effective antiviral agents against Turnip mosaic virus in Brassica rapa
Journal of General Plant Pathology 79 (3), 198-204
Abstract: Plants may activate posttranscriptional gene silencing (PTGS) as an immunity system when they are infected with viruses. Viruses may in turn interfere with this system by producing RNA silencing suppressor (RSS) proteins; most RSSs bind to viral small interfering RNAs (siRNAs). We previously reported that ascorbic acid (AsA) has the ability to interfere with the binding between viral siRNAs and viral RSSs in vitro. We thus expected that AsA-treated plants would show some tolerance to virus infection because the host PTGS will be strengthened by AsA. Brassica rapa subsp. rapa was inoculated with Turnip mosaic virus and treated with the AsA derivatives, L(+)-ascorbic acid 2-sulfate disodium salt dihydrate (AsA-SO₄), L(+)-ascorbyl palmitate (AsA-Pal) and dehydroascorbic acid (DHA) at 1 h postinoculation. The number of infection sites on inoculated leaves decreased by around 40 % after AsA-SO₄ and AsA-Pal treatments and by 80 % after DHA treatment compared with the untreated control. As evidenced by an enzyme-linked immunosorbent assay, viral accumulation was significantly reduced after regular sprays with the AsA derivatives and DHA. In a detached leaf assay, AsA clearly functioned as a viral inhibitor in cells. Additionally, we confirmed that DHA also worked in the silencing pathway because its antiviral effect was not observed in the silencing-defective double mutant dcl2/dcl4 of Arabidopsis thaliana. On the basis of these results, we concluded that the AsA derivatives and DHA can significantly reduce viral infection and accumulation and that we can develop those compounds as a practical antiviral agent in the future.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Chikara Masuta

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Turnip mosaic virus	Brassica - other species