Molecular Biological Study on the Host-Specificity of Plant Viruses

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 05454062
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 植物保護
• Research Institution: Kyushu University
• Principal Investigator: TAKANAMI Yoichi Kyushu University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (50243944)
• Co-Investigator(Kenkyū-buntansha): FURUYA Naruto Kyushu University, Faculty of Agriculture, Assistant Professor, 農学部, 助手 (10211533) ; MATSUYAMA Nobuaki Kyushu University, Faculty of Agriculture, Professor, 農学部, 教授 (40108676)
• Project Period (FY): 1993 – 1995
• Keywords: Arabidopsis thaliana / Plant virus / Host-specificity / Molecular biology / Infectious RNA transcript / Pseudorecombinant

Research Abstract

Molecular biological studies on the host-specificity of plant viruses were carried out to elucidate the interactions between host plants and viruses and to obtain the basis of the control of virus diseases of plants.
1) A curuciferous weed plant, Arabidopsis thaliana, was selected as an experimental plant to establish an efficient model system for molecular biological analyzes of the virus-host interactions. Culture method and ecotype of the plant suitable for plant virus research were selected and optimum conditions for inoculation of the plant with cucumber mosaic virus (CMV) were determined. Furthermore, over 5,000 seedlings of the plants, clomosomal DNA of which were tagged with the transfer region in Tiplasmid of Agrobacterium tumefaciens, were screened for mutants as to CMV infection. However, none of the mutated plants have so far been obtained.
2) Quantitative and histochemical studies revealed that a brassica strain of CMV (CMV-D8) isolated from a Japanese radish plant carrying mosaic symptoms can infect and multiply much more efficiently than the other CMV isolates such as a yellow strain of CMV (CMV-Y). To know the mechanism (s) of the host-specificity of plant viruses from molecular biological aspects, we have successfully constructed full-length cDNA clones of all genome RNAs of CMV-D8 from which infectious RNAs could be transcribed in vitro. Various pseudorecombinants were prepared using the RNA transcripts and inoculated onto Japanese radish plants. Then, multiplication of the viruses were histochemically investigated using the tissue-printing technique. The results showed that the genetical information encoded in both RNA2 and RNA3 of the CMV genomes directed the ability of CMV-D8 to efficiently infect the plant.