Hyoun Sub Lim
Chungnam National University, South Korea
Title: A methionine to threonine substitution in the overlapping MP/CP reading frames causes the symptom differences between two isolates of Youcai mosaic virus
Biography
Biography: Hyoun Sub Lim
Abstract
In Asia, Chinese cabbage (Brassica rapa) is mainly grown and utilized in various ways as a healthful food source. However, increasing virus damage resulting from changes in trade of agriculture products including seedlings and seeds, as well as climate change and repeated cultivation, has reduced Chinese cabbage production. According to recent research, three plant viruses - Turnip mosaic virus (TuMV), Cucumber mosaic virus (CMV), and Youcai mosaic virus (YoMV) - are reported to affect Chinese cabbage yields. Recently we detected new isolates of YoMV in Korean radish fields, and full-length infectious clones of two isolates were generated in the dual 35S /T7 promoter driven pJY binary vector. Four amino acid differences (V383I, M492I in 125kDa, T1245M in 182kDa and M17T in CP) between two isolates resulted in either severe or mild symptom development in Nicotiana benthamiana. In order to reveal the amino acids related to severe pathogenesis, four hybrid constructs were generated through by gene exchanges between the isolates. Hybrid constructs maintaining CP residue 17 as threonine in the MP/CP overlap region developed severe symptoms. Further analysis expressing CPM(17)T from a Potato virus X vector produced differential symptoms in N. tabacum cv. Xanthi, inducing HR (T17) and mild symptoms (M17) respectively.