We propose to use IVET to investigate the interaction between P. syringae pv. maculicola race M6 (Psm M6) and Arabidopsis. Psm M6 is compatible on ecotypes of Arabidopsis lacking Rpm1. However, it carries avrRpm1 and is incompatible on Arabidopsis expressing Rpm1. A small percentage of Psm M6 cells recovered after growth in planta are virulent on all tested ecotypes of Arabidopsis. Rearrangements in the genome, resulting in a Tn3 insertion into avrRpm1 and an excision of a plasmid, were demonstrated to have occurred in these now virulent cells. This is an active response by Psm M6 to signals of the plant. We are interested in characterizing the induced genes of Psm M6 for initiating disease in compatible Arabidopsis plants and the genes that respond to in planta signals which lead to the plasmid excision. These studies will provide a comprehensive analysis of how Psm M6 initiates disease in Arabidopsis. IVET is a promoter-trapping technique that has been used successfully to identify induced virulence genes of many pathogenic bacteria. IVET will be adapted to increase its capability, reduce the amount of labor required, and examine only the initial events of pathogenesis. All necessary DNA constructs are in our possession and necessary modifications are facile and in progress. We have already demonstrated that several facets of the proposal are feasible. Finally, we present several possible directions to pursue in characterizing the mechanisms of pathogenesis. A complete understanding could lead to the creation of novel, more robust forms of resistance against phytopathogenic bacteria.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
3F32GM020296-02S1
Application #
6682990
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Tompkins, Laurie
Project Start
2001-01-01
Project End
2003-06-30
Budget Start
2003-01-01
Budget End
2003-06-30
Support Year
2
Fiscal Year
2003
Total Cost
$24,074
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Chang, Jeff H; Urbach, Jonathan M; Law, Terry F et al. (2005) A high-throughput, near-saturating screen for type III effector genes from Pseudomonas syringae. Proc Natl Acad Sci U S A 102:2549-54
Chang, Jeff H; Goel, Ajay K; Grant, Sarah R et al. (2004) Wake of the flood: ascribing functions to the wave of type III effector proteins of phytopathogenic bacteria. Curr Opin Microbiol 7:11-8
Singer, Alex U; Desveaux, Darrell; Betts, Laurie et al. (2004) Crystal structures of the type III effector protein AvrPphF and its chaperone reveal residues required for plant pathogenesis. Structure 12:1669-81