2002 Fiscal Year Final Research Report Summary
Studies on replication, pathogenicity and transmission of plant RNA viruses in the genus Furovirus
| Project/Area Number |
13460020
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物保護
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
SHIRAKO Yukio Asian Natural Environmental Science Center, Professor, アジア生物資源環境研究センター, 教授 (90143023)
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| Project Period (FY) |
2001 – 2002
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| Keywords | genus Furovirus / Soil-borne wheat mosaic virus / RNA reassorment / infectious cDNA clone / barley mesophyl protoplast / viral RNA replication / pathogenicity / transmissibility |
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| Research Abstract |
Soil-borne wheat mosaic virus (SBWMV) is the type species in the genus Furovirus with bipartite plus-sense RNA genome encapsidated in rod-shaped virions. SBWMV infects wheat and barley plants, causing mosaic and stunt diseaese. SBWMV is transmitted by and retained in soil-inhabiting fungus and therefore it is quite difficult to control this virus disease from the infested field. In this study, we investigated replication, pathogenicity and transmission of SBWMV for the purpose of controlling the disease.
1. Three full-length infectious cDNA clones for Japanese, American and English isolates of SBWMV were constructed. Also, an infectivity assay, a barley mesophyl protoplasts system was developed for SBWMV. Reassortment experiments among the three isolates using barley protoplasts showed that all RNA1 and RNA2 combinations supported viral RNA replication, indicating a close relationship among the three geographical isolates.
2. Infection of SBWMV to wheat plants requires temperatures lower than 20 ℃. Barley protoplasts inoculated with infectious in vitro transcripts were incubated at temperatures between 15 ℃ and 25 ℃, and it was proved that the optimal temperature for RNA replication is 17 ℃.
3. Wild-type RNA2 of SBWMV undergoes frequent deletion mutation when the virus was passaged at 17 ℃ and deletion mutants cause more severe symptoms on wheat plants that the wild-type virus. Deletion mutation was analyzed using full-length infectious RNA2 transcripts in inoculum and found to occur in-frame to the upstream capsid protein gene. Symptom severities correlated with the length of deletion.
As described above, the fundamental information, materials and methods were obtained for further detailed analysis on replication, pathogenicity and transmission of furoviruses.
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Research Products
(6 results)
