RT article T1 Molecular characterization of CEVd strains that induce different phenotypes in Gynura aurantiaca: structure-pathogenicity relationships A1 Chaffai, M. A1 Serra, P. A1 Gandia, M. A1 Hernandez, C. A1 Durán-Vila, Núria AB Two Citrus exocortis viroid isolates (CEVd-s and CEVd-129) that induce severe and mild symptoms in Gynura aurantiaca, respectively, have been characterized. They present nucleotide sequences in the pathogenicity motifs P-L, C and P-R similar to those of "Class A" and "Class B". Infectivity and symptom expression in G. aurantica and tomato were evaluated with a selection of sequence variants recovered from both isolates. As expected, the two variants selected from CEVd-s induced severe symptoms. The variants selected from CEVd-129 induced mild symptoms, except one of them, named MJ, that presented an unusual genotype and induced severe symptoms in G. aurantiaca. The biological properties of MJ show that the two nucleotide changes of the C domain normally associated with the P-L and P-R motifs of "Class B" strains are not implicated in symptom expression. The relationship between "Class A" and "Class B" strains with the symptoms induced in clementine trees grafted on trifoliate orange is discussed. SN 0304-8608 YR 2007 FD 2007 LK http://hdl.handle.net/20.500.11939/5020 UL http://hdl.handle.net/20.500.11939/5020 LA en NO Chaffai, M., Serra, P., Gandia, M., Hernandez, C., Duran-Vila, N. (2007). Molecular characterization of CEVd strains that induce different phenotypes in Gynura aurantiaca: structure-pathogenicity relationships. Archives of Virology, 152(7), 1283-1294. DS MINDS@UW RD Jan 16, 2021