COAT PROTEIN-MEDIATED PROTECTION AGAINST PLUM POX VIRUS

The coat protein gene of Plum Pox Virus (PPV) was set under the control of the CaMV 35S promoter and introduced into an Agrobacterium tumefaciens binary vector.
Leaf explants from Nicotiana clevelandii and Nicotiana benthamiana – herbaceous host plants for PPV – were transformed with Agrobacterium strain LBA 4404 containing the plasmid pBinPPVm.
Shoots regenerated on selection media containing kanamycin were tested for the expression of the PPV coat protein gene by ELISA and immuno western blot.
After rooting and acclimatisation plants were tested for the protection against PPV. Following the inoculation plants were investigated for development of symptoms and virus accumulation.
The phenomenon of virus resistance was observed at different levels when transgenic plants, expressing the coat protein (CP+), and control plants (CP-) were compared after challenge infection with PPV. Nicotiana clevelandii CP+ plants circumvent virus accumulation.
After an initial increase in virus titer similar to the control plants, some CP+ plants showed a reduced accumulation of virus and inhibition of the systemic spread, characterized by decrease of the virus titer and formation of new symptomless leaves.
In other Nicotiana clevelandii CP+ plants virus accumulation was inhibited and disease symptoms never appeared. Nicotiana benthamiana CP+ plants were also protected.
After a temporary virus accumulation, virus titer decreased without the appearance of symptoms with the exception of a few plants, which showed a delay of thirty days in the development of symptoms post challenge infection.

XV International Symposium on Fruit Tree Diseases

A. da Câmara Machado, F. Regner, H. Steinkellner, D. Mattanovich, V. Hanzer, H. Weiss, M. Laimer da Câmara Machado, H. Katinger

https://doi.org/10.17660/ActaHortic.1992.309.29