virus resistance by tissue culture

1. Virus resistance by
tissue culture
Plant tissue culture

3. Introduction
• A virus resistance is a mutation in a virus gene that allows the virus to
become resistant to treatment with a particular antiviral drug.
• The term was first used in the management of HIV, the first virus in
which genome sequencing was routinely used to look for
drug resistance.

4. Plant virus
• Plant virus genomes are relatively small and therefore are physically
unable to encode all the products needed for development of plant
• When establishing infection, viruses recruit natural host factors to
replicate and spread.
• These factors are candidate targets for novel virus resistance
approaches.

5. Virus resistance
• Plant viruses and their vectors cause serious economic losses, limit
crop production, and have negative effects on the quality and security
of food supplies.
• Infection by viruses is a major cause of degeneration of potato seed
stocks particularly by aphid-borne viruses.
• Current approaches to the protection of plants from viruses are
primarily based on poorly understood mechanisms and it is likely that
more detailed knowledge will lead to improved virus management.

6. Virus resistance by tissue culture
• Putative virus-resistant transgenic plants are usually transferred from
tissue culture to a greenhouse or growth chamber to screen for
resistance
• To reduce initial screening costs and time we developed mechanical
and graft inoculation methods suitable for tissue culture use.
• The in vitro methods were validated by comparing them with similar
greenhouse screens using putative potato virus Y strain replicase-
mediated resistant regenerants of the potato cultivar Atlantic.

7. • Five transgenic lines were tested, with similar results obtained from in
vitro and greenhouse experiments.
• Two of the transgenic lines, A1 and A3, showed the greatest
resistance to PVY degrees infection, as indicated by low enzyme-
linked immunosorbent assay values and infection rates.

8. • In vitro mechanical inoculation methods were also used to infect wild-
type tomato and tobacco plants with cucumber mosaic virus and
potato virus Y.
• Potato plants were also infected with the phloem-restricted potato
leaf roll virus, a low-titer virus, using in vitro graft inoculation
methods.
• These results suggest the potential usefulness of these simple,
effective, and economical techniques for screening large numbers of
putative virus-resistant plants.