Molecular characterization of variants of a new 'rule-breaking' tobacco rattle virus RNA2 in potatoes.
In potato tubers showing pronounced corky ringspot symptoms, two related 'rule-breaking" tobacco rattle virus (TRV) RNA2s, named Da-2 and Db-2, were identified. Their coat protein (cp) genes are preceded on the 5' side by an additional gene for a 35 kDa protein for which no relationships with previously described TRV genes or their expression products were found. With estimated 4296 and 4247 nucleotides (nts) the two RNAs are the longest TRV RNA2s described so far. The difference in size between Da-2 and Db-2 is due to a duplication of a stretch of 49 nts in the 5' untranslated region of Da-2. An alignment of TRV coat proteins (cp) revealed that up to about amino acid (aa) 176 they form two rather uniform groups. The much shorter C-terminal parts of the cps, however, differ considerably in size and composition. With 56 aa this C-terminal part is much longer in the Da and Db sequences than in all other TRV cps. It differs in 18 positions in the two strains whereas their N-terminal 184 aa differ only in two positions. - In young potato plants developing from bud-cuttings of TRV Db-infected potato tubers which had been planted in soil free of virus and nematodes a gradual degradation of Db-2 was observed. In the newly formed rootlets already five days after planting a deletion of 80 nts was observed in the putative 2b gene which in other TRV strains encodes a protein necessary for nematode transmission. Thirty three days after planting the entire 2b gene, 119 nts at the 3'end of the cp gene and a portion of the original 3'untranslated region of Db-2 had been lost in the newly formed roots, leaves and stolons. The gene for the 35kDa protein was the only one which was not affected by deletions which seems to emphasize its importance for the virus. Fifty days after planting only TRV RNA1, but no TRV RNA2 were detectable.
['Lindner|Kerstin|K|', 'Hilbrich|Inga|I|', 'Koenig|Renate|R|']
D020121:5' Untranslated Regions D000595:Amino Acid Sequence D001483:Base Sequence D036022:Capsid Proteins D015870:Gene Expression D054884:Host-Pathogen Interactions D010935:Plant Diseases D018515:Plant Leaves D018517:Plant Roots D035281:Plant Tubers D010942:Plant Viruses D020871:RNA Stability D012367:RNA, Viral D016415:Sequence Alignment D012689:Sequence Homology, Nucleic Acid D011198:Solanum tuberosum
Corky ringspot-disease Tobacco rattle virus RNA2 degradation in potatoes ‘Rule-breaking’ tobacco rattle virus RNA2s