Poster: Plant Pathogen/Symbiont Interactions

Abs # 727: Expression profiling of TMV-induced N-gene mediated defense response

Presenter:	Yamamoto, Miki L, miki_y@uclink.berkeley.edu
Authors	Yamamoto, Miki L (A)   Hu, Gongshe  (C)   Stagalkina, Svetlana  (B)   Hart, Amy  (B)   Briggs, Matthew  (A)   Buell, Robin  (B)   Baker, Barbara J (A) (C)
Affiliations:	(A): Plant and Microbial Biology, University of California, Berkeley (B): The Institute of Genomic Research, Rockville MD (C): Plant Gene Expression Center, University of California and USDA/ARS, Albany CA

To further elucidate the molecular mechanism of N-mediated resistance to tobacco mosaic virus (TMV), we are taking a genomic approach to identify genes involved in signaling N-mediated TMV resistance. The N gene, isolated from Nicotiana glutinosa, was found to mediate TMV resistance when introduced into the TMV-susceptible tomato cultivar VF36, allowing access to genetic tools not available in tobacco systems. Expression profiling of TMV-resistant (NN) and susceptible (nn) tomato using 10,000 element potato are being carried out to identify signaling components of the N pathway. A suppressor mutant of N in tomato son1 has been shown to impair multiple R gene pathways, demonstrated by broad-spectrum hypersusceptibility to viral, bacterial and fungal pathogens. Mapping and cloning of son1 is underway; and, the son1 mutant is being exploited to identify signaling components of the N pathway in expression profiling studies. Groups of genes showing coordinated expression and unique patterns of expression have been identified, and included expected and novel genes included. Candidate signaling genes identified by gene profiling studies of TMV resistant, susceptible, and the enhanced susceptible mutanta are being tested in the virus-induced gene silencing (VIGS) system to establish function in N-mediated resistance as well as other R gene resistance.