2005 Fiscal Year Final Research Report Summary
Mechanism that enable some plant viruses multiply both in plants and insect vectors
| Project/Area Number |
15380038
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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 |
Plant pathology
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| Research Institution | National Agriculture and Research Organization |
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Principal Investigator |
OMURA Toshihiro National Agricultural Research Center, Department of Plant Pathology, Laboratory head, 中央農業総合研究センター・病害防除部, 室長 (20355499)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIKI Tamaki National Agricultural Research Center, Department of Plant Pathology, Senior Researcher, 中央農業総合研究センター・病害防除部, 主任研究官 (70355501)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Rice dwarf virus / insect isolate of RDV / vector transmission / host specificity |
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| Research Abstract |
Viroplasms, namely, discrete cytoplasmic inclusions were formed that contained the nonstructural proteins Pns6,Pns11 and Pns12 of RDV in cells infected with Rice dwarf virus (RDV). Core proteins P1,P3,P5 and P7 and viral core particles were identified in the interior region of the inclusions. By contrast, the accumulation of the outer capsid proteins P2,P8 and P9 and of intact viral particles was evident in the peripheral regions of the inclusions. These observations suggest that core particles were constructed inside the inclusions, while outer capsid proteins were assembled at the periphery of the inclusions. Viral inclusions were showed to be the sites of viral RNA synthesis. The assembled viral particles were found to move from infected insect cells to neighboring uninfected cells through tubules approximately 85 nm in diameter, which is composed of the nonstructural protein Pns10 encoded by the viral genome.
The P2 as well as Pns10 among 12 viral proteins were missing in rice plants vegetatively maintained over four years by cutting of the plants without the concern of insect vectors. On the contrary, all the 12 proteins were detected in RDV infected rice plants inoculated using viruliferous insect, in viruliferous insects maintained mainly through transovarial transmission, and RDV infected vector cells maintained without concern of plant. The P2 is reported to be essential for viral infection to insect cells (Yan et al.,1996) and the Pns10 was found to have a function to transport RDV to neighboring cells in infected insect cells. All these results demonstrate that the P2 and Pns10 proteins are key proteins that enable RDV multiply both in plants and insect vectors.
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