Richard F. Allison  Associate Professor of Plant Biology;  Ph.D., 1986, North Carolina State University;  Research Associate, 1986­1989, Institute for Molecular Virology, University of Wisconsin, Madison.

Email: allison@pilot.msu.edu Phone: (517) 432-1548 Lab: 355-4578 Home Department: Botany and Plant Pathology,

Hundreds of plant viruses have now been identified, and most of them infect only a limited number of plant species. One project in our lab examines two closely related RNA viruses that have distinct host ranges. Full length cDNA clones have been made for both viruses and RNA transcripts, the biological equivalent of viral RNA, are prepared from the clones and used to infect plants. Standard recombinant DNA techniques are used either to introduce specific mutations or exchange genomic segments between these viruses. With these techniques, we are mapping regions of the genome that influence host specific interactions.

A second project involves a virus that causes necrosis in bean varieties that express a specific resistance gene. Closely related viruses do not cause necrosis. Using techniques similar to those described above, viral genes are being exchanged between cDNA clones to map the necrosis inducing gene of the virus.

Plants can be made resistant to specific viruses by genetically modifying the plant to express a viral gene. These genetically engineered plants promise to provide an effective method of controlling disease. However, several questions remain concerning the environmental risk of the release of these modified plants. One concern is that viral RNA expressed by the transgenic plant may recombine with RNA of a challenging virus. The role of RNA recombination in the evolution of plant viruses has been firmly established and we are currently evaluating the possibility that such recombination in transgenic plants may enhance the rate of RNA virus evolution. We have developed a sensitive bioassay to detect recombinant viruses and are using it to predict the frequency of RNA recombination in transgenic plants.

SELECTED PUBLICATIONS:

Schneider,  W. L., A. E. Greene, R. F. Alison (1997) The carboxy­terminal two­thirds of the cowpea chlorotic mottle bromovirus capsid protien is incapable of virion formation yet support systemic movement. Journal of Virology. June 1997. Vol. 71. No 6 . Schneider WL, et al.

Greene,  A. E., and R. F. Allison (1996) Depletion in the 3' untranslated region of cowpea chlorotic mottle virus transgene reduce recovery of recombinant viruses in transgenic plants. Virology 225: 231­234, Article No. 0593Greene AE, et al.

Fang, G.M ., R. F. Allison, E.M Zambolim, D.P. Maxwell, R.L. Gilbertson (1995) The complete nucleotide sequence and genome organization of bean common mosaic virus (NL3 strain). Elsevier Virus Research 39: 13­23. Fang GW, et al.

Greene A.  and R. F. Allison (1994) Recombination between viral RNA and transgenic plant transcripts. Science 263:1423­1425.Greene AE, et al.

Allison, R. F.,C. Thompson, and P. Ahlquist (1990) Regeneration of a functional RNA virus genome by recombination between deletion mutants and requirement for cowpea chlorotic mottle virus 3a and coat genes for systemic infection. Proceedings of the National Academy of Sciences (USA) 87:1820­1824.

Other Publications
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