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Resistance

Symptom Variation in Different Arabidopsis thaliana Ecotypes Produced by Cauliflower Mosaic Virus. Scott M. Leisner, Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853; Stephen H. Howell, Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853. Phytopathology 82:1042-1046. Accepted for publication 25 June 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/Phyto-82-1042.

To determine the role of host factors in the systemic infection of Arabidopsis thaliana by cauliflower mosaic virus (CaMV), variation in systemic symptoms produced by three different viral isolates in 23 different A. thaliana ecotypes was studied. Differences in the overall pattern of viral symptoms were observed when different A. thaliana ecotypes were inoculated with a given CaMV isolate. In most cases, the pattern differences correlated with the rate of plant development. Symptoms on early flowering ecotypes were confined to the uppermost parts of the plant, the flower stalk and cauline leaves, whereas symptoms on late flowering ecotypes were more widespread, appearing on the rosette leaves. One ecotype, En-2, appeared to be resistant to CaMV for reasons unrelated to plant development. CaMV appears to replicate and move from cell to cell in the inoculated leaves of this ecotype, but it does not move systemically. Differences were also observed in the ability of different viral isolates to produce symptoms in a given A. thaliana ecotype. In general, one viral isolate, W260, produced more severe symptoms than the other two isolates, CM4-184 and CM1841.