Scientists have identified a new way to breed brassicas, which include
broccoli, cabbage and oilseed rape, resistant to a damaging virus. Their
discovery has characterised a form of resistance that appears to be durable,
broad-spectrum and unlikely to be overcome by the virus over time. Turnip
mosaic virus (TuMV) is an economically devastating virus that infects a wide
range of cultivated plants, but especially brassicas.
In research published recently in the Journal of General Virology,
scientists at Warwick HRI and collaborators have identified genes that
confer resistance to the virus and, crucially, as multiple genes are
involved, provide resistance that the virus appears not to have been able to
evolve to overcome.

The research, funded by the Biotechnology and Biological Sciences
Research Council (BBSRC) and others, could have important broader
implications for plant breeders and farmers as TuMV is a member of the
Potyvirus family - the biggest family of viruses that attack plants - and an
important model for understanding other viruses.

The Warwick HRI scientists have examined a number of types of genes
that determine plant responses to virus attack. One response is for the
plant to kill off individual cells if they become infected, thereby
restricting the viral infection to a very localised area of the plant.
Another response is to restrict virus movement within the plant and stop its
spread from leaf to leaf. The researchers have identified a number of genes
that appear to not allow any replication of the virus in plants when it is
introduced into the plant.

Dr John Walsh, the research group leader, said: ?Turnip mosaic virus
can cause big economic losses for farmers. We have identified multiple genes
that give some varieties of brassica resistance to the virus. By breeding
these genes into commercial varieties of the crop, using conventional
techniques, breeders can protect them from attack. But most importantly, we
have identified broad-spectrum resistance provided by a number of genes.
This means we potentially have the means to develop brassicas, such as
broccoli, that will be robust enough to prevent the virus mutating to
overcome the resistance.?

Professor Simon Bright, Director of Warwick HRI, commented: ?This
research demonstrates the importance of centres such as Warwick HRI in
linking fundamental bioscience to developments that benefit growers and
consumers. In the three years since we transferred to become part of the
University of Warwick, Warwick HRI has built on its core strengths in
horticulture and is now at the forefront of efforts, such as the BBSRC Crop
Science Initiative, to turn excellent plant science in to real benefits for
crop production.?

Dr Walsh?s team has recently been awarded more funding by BBSRC under
its Crop Science Initiative to take this research further.


[www.bbsrc.ac.uk]