MOVEMENT OF CYMBIDIUM MOSAIC VIRUS AND TRANSGENIC RESISTANCE IN DENDROBIUM ORCHIDS
The movement of Cymbidium mosaic virus (CyMV) was compared with that of Odontoglossum ringspot virus (ORSV) in Dendrobium hybrid orchids using tissue blot immunoassay (TBIA). We found that CyMV moves systemically in vascular tissues but ORSV moves only cell-to-cell in this host. TBIA was also used to monitor the replication and movement of CyMV in transgenic orchid plants. We have transformed Nicotiana benthamiana and Dendrobium orchids with the coat protein (CP) gene, a movement protein (MP) gene, and a mutated movement protein (mutant-MP) gene of CyMV. Transgenic N. benthamiana and orchid plants were evaluated for CyMV resistance after mechanical inoculations in greenhouse experiments under controlled conditions. Four of twelve (33%) transgenic N. benthamiana lines transformed with the mutated MP gene were resistant to CyMV infection; four of sixteen (25%) transgenic N. benthamiana transformed with the CP gene were resistant. Five transgenic orchid lines transformed with the CP or the MP genes tested so far all became infected, whereas 5/25 lines transformed with the mutated MP gene showed partial resistance to CyMV infection. Further characterization of these transgenic orchid lines for CyMV resistance is in progress.
Borth, W.B., Barry, K., Obsuwan, K., Xu, M.Q., Liu, R.W., Kuehnle, A.R. and Hu, J.S. (2006). MOVEMENT OF CYMBIDIUM MOSAIC VIRUS AND TRANSGENIC RESISTANCE IN DENDROBIUM ORCHIDS. Acta Hortic. 722, 137-146
CyMV, transgenic orchids, virus resistance