1997 Fiscal Year Final Research Report Summary
Molecular analyzes of the mechanism of plant virus pathogenicity
| Project/Area Number |
08306003
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
FURUSAWA Iwao Kyoto University, Guraduate School of Agriculuture, Professor, 農学研究科, 教授 (10026594)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Yuichirou Department of Life Science, Graduate School of Arts and Sciences, University of, 総合文化研究科生命環境科学系, 助教授 (60183125)
ISHIKAWA Masayuki Hokkaido University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (70192482)
HOSOKAWA Daijirou Tokyo University of Agriculuture and Technology, Professor, 農学部, 教授 (50014957)
UEDA Ichiro Hokkaido University, Faculty of Agriculture, Professor, 農学部, 教授 (10113523)
HIBI Tadaaki University of Tokyo, Faculty of Agriculture, Professor, 農学部, 教授 (50261954)
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| Project Period (FY) |
1996 – 1997
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| Keywords | CaMV / TMV / CMV / PVX / ToMV / RNA polymerase / host factor / host specificity |
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| Research Abstract |
We have comprehensively studied the mechanism of genome replication of various plant viruses. Chronological analyzes of the accumulation of viral gene products in cauliflower mosaic virus (CaMV)-infected turnip protoplasts showed that the expression of each gene is differentially regulated. It has also been suggested that subgenomic RNAs as well as the polycistronic 35S RNA are involved in the expression of CaMV genes, indicating that CaMV uses a unique strategy for the gene expression during virus multiplication. Two domains of the 180K protein gene of tobacco mosaic virus (TMV)-OM,each containing the sequence motifs of methyltransferase or RNA polymerase, have shown to exhibit the binding activity with TMV-RNA.By immunoaffinity chromatography using antibodies specfic to the domains, heterodimers consisting of 130K and 180K viral proteins, which exhibited TMV-RNA dependent RNA synthesis in vitro, were isolated from TMV-infected tobacco leaves. We have analyzed Arabidopsis thaliana mutants designated cum1 and cum2, in which the multiplication of cucumber mosaic virsu (CMV) is delayd. Furthermore, we have been trying to clone the CUM1 gene by the positional cloning procedure. We have isolated solubilized RNA polymerase synthesizing subgenomic RNA from tobacco protoplasts inoculated with potato virus V (PVX). Amino acid 979 of the 130-and 180-kDa proteins of tomato mosaic tobamovirus (ToMV) plays an important role in overcoming the tomato Tm-1 resistance gene. Introduction of a single amino acid substitution (Gln979 to Ile) into the ToMV proteins rendered the mutant virtually unable to replicate in tomato cells while it replicated perfectly in tobacco cells, indicating the importance of the region surrounding the amino acid 979 in terms of host specificity determinants.
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