FULLLENGTH OR TRUNCATED MOVEMENT PROTEINS OF CYMBIDIUM RINGSPOT TOMBUSVIRUS DO NOT CONFER RESISTANCE ON TRANSGENIC NICOTIANA PLANTS
P. Ciuffreda, L. Rubino, M. Russo
The full-length and truncated versions of the cymbidium ringspot tombusvirus (CymRSV) movement protein gene under the control of the cauliflower mosaic virus 35S promoter and terminator were used to transform Nicotiana benthamiana plants. Integration of the viral sequence in the plant genome was confirmed by PCR amplification of DNA extracts from transformed plants and by detection of virus-related transcripts in RNA extracts. Western blot analysis failed to show the presence of the transgene-encoded protein in transgenic plants. None of these plants was protected from infection when challenged with CymRSV, regardless of the type of transgene, whether full-length or truncated. It is suggested that RNA-mediated resistance was not acting in these plants and that failure to obtain resistance was due to lack of accumulation of the transgenic protein.