Phytopathology 80:238-242.

Symptom Intensification on Cruciferous Hosts by the Virulent Satellite RNA of Turnip Crinkle

Virus Xiao Hua Li and Anne E. Simon

Department of Plant Pathology, University of Massachusetts, Amherst 01003.

Satellite RNAs are small, single-stranded, linear, or circular RNAs that require a helper virus for replication. Turnip crinkle virus supports, the replication of at least three satellite RNAs, one of which (sat-RNA C) was previously found to intensify viral symptoms on turnip cultivar Just Right. For this report, we have analyzed the ability of the virulent sat-RNA C to intensify symptoms on other cruciferous plants. Sat-RNA C was found to exacerbate symptoms on all hosts where TCV producedvisible symptoms including cultivars of Brassica rapa and Arabidopsis thaliana. However, sat-RNA C did not have any intensifying effect on four cultivars of B. rapa that were tolerant to TCV infection. Lack of symptoms was not accompanied by lower accumulation of TCV or sat-RNA C. These results support our previous model that symptoms induced by TCV and sat-RNA C are the possible result of an analogous interaction between their similar 3' end domains and an unidentified factor present in some hosts.