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Parasitism
and Pathogenesis in Plants and Nematodes
Roots
supply plants with water and nutrients, act as an anchor
point for the plant, and produce valuable chemical
substances that are exchanged with the shoot and leaves.
While plants evolved roots to better find nutrients,
they have also developed complex relationships with the
micro- and macro-organisms contained within the soil.
These relationships range from mutual symbiosis to
those of parasitism and pathogenesis.
My laboratory’s focus is on the role of biotrophic
parasitism in plant roots.
Biotrophic parasitism occurs when an organism invades
a plant host and alters plant gene expression in an effort
to remove nutrients from the host.
Through the removal of nutrients, the invading
pathogen creates a nutrient sink at the infection site, so
that the host is disadvantaged but not killed. This
type of parasitism can result in serious economic losses of
crop plants.
Biotrophic parasites can be bacteria, fungi, animals and
even other plants. For
our studies in biotrophic parasitism, we chose to work with
two important biotrophic pests of roots: plant-parasitic
nematodes and Agrobacterium
rhizogenes. Both
of these pests are important plant pathogens whose disease
is manifested through the successful modification of gene
expression resulting in a favorable environment in the plant
root for the invading pest.
Plant-parasitic nematodes alter gene expression
through secretions which results in the development of a
highly-specialized feeding site.
A. rhizogenes induce
the production of “hairy roots” through the transfer of
bacterial DNA into the chromosome of the plants.
This transferred DNA contains genes that induce the
formation of roots which become potent sinks of
photosynthates for the invading bacteria.
By thoroughly studying these biotrophic interactions,
we will generate a better understanding of plants’
interaction with their environment and develop new
strategies for more sustainable methods of agricultural
production.
Dr. Christopher Taylor received
his B.Sc. in Biochemistry from Penn State University and his
Ph.D. in Genetics from North Carolina State University. |
