Dissecting the signaling pathway regulating early stages in parasitic plant, host plant interactions

By Lee Nguyen, Biotechnology ’14

Parasitic plants pose a serious threat to the world’s agriculture and environment.  Understanding the parasitism signaling pathway will help identify methods of pest control as well as pest resistance. One gene that enters the parasitic signaling pathway early is TvQR1, a gene that encodes an enzyme that catalyzes an oxidation-reduction reaction crucial for development of a root like outgrowth called a haustorium. In parasitic plants, TvQR1 is transcriptionally activated upon host contact and my project is to study the promoter of this gene, pQR1, in a nonparasitic plant. The promoter was cloned into a plasmid vector containing the GUS reporter gene and transformed into Arabidopsis, a nonparasitic plant. I am selecting for transformed seeds by plating them on culture medium containing the antibiotic kanamycin. The successfully transformed seeds will be verified by PCR. Then, transcription regulated by the pQR1 promoter will be analyzed from the GUS expression patterns. The results will demonstrate how the promoter is regulated following contact with host plants and illustrate how TvQR1 is cis- or trans- regulated. Understanding how parasitic plants identify their hosts by studying this signaling pathway will suggest novel approaches for biologically controlling parasitic weeds.

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