Trans-acting untranslated elements of groundnut rosette virus satellite RNA are involved in symptom production.
Isolates of groundnut rosette umbravirus (GRV) contain a satellite RNA (sat-RNA), about 900 nucleotides (nt) in length, different variants of which are responsible for the symptoms of different forms of rosette disease in groundnuts and, in the particular instance of sat-RNA YB3b, for the production of yellow blotch symptoms in Nicotiana benthamiana. Sat-RNA YB3b does not affect the accumulation of GRV genomic or subgenomic RNAs in infected plants. Replication of sat-RNA YB3b and induction of yellow blotch symptoms do not require the production of any sat-RNA-encoded proteins. Experiments with deletion mutants identified three functional untranslated elements in sat-RNA YB3b. One (designated R) comprises nt 47-281, is essential for sat-RNA replication and appears to be cis-acting. The other two (designated A and B) comprise nt 280-470 and 629-849, respectively, are both involved in yellow blotch symptom production and can act in trans. Element A contains the determinant that is unique to sat-RNA YB3b. The process of symptom induction by sat-RNA YB3b apparently involves a novel type of specific interaction of two untranslated RNA elements, which can complement each other, with a host factor or factors.
Taliansky
M E
ME
Scottish Crop Research Institute, Invergowrie, Dundee, UK.
Robinson
D J
DJ
D010367:Arachis / Q000821:virology*; D016366:Open Reading Frames; D010942:Plant Viruses / Q000235:genetics*; D019244:RNA, Satellite / Q000502:physiology*; D012367:RNA, Viral / Q000502:physiology*; D014779:Virus Replication
D019244:RNA, Satellite; D012367:RNA, Viral