EFR-induced plant immunity can be effective against Pseudomonas syringae infection and Agrobacterium transformation.
F. YANG (1), M. Guo (1), G. Felix (3), J. Alfano (4) (1) Center for Plant Science Innovation and the Department of Plant Pathology, University of Nebraska, U.S.A.; (2) Center for Plant Science Innovation and the Department of Plant Pathology, University of Nebraska, U.S.A.; (3) Center of Plant Molecular Biology, University Tübingen, Germany; (4) Center for Plant Science Innovation and the Department of Plant Pathology, University of Nebraska, U.S.A.

Elongation factor Tu (EF-Tu), a key component of bacterial protein synthesis, acts as a pathogen-associated molecular pattern (PAMP) triggering innate immune response in plants. The Arabidopsis pattern-recognition receptor (PRR) EFR senses bacterial EF-Tu and initiates immune signaling. It has been known since the discovery of EFR that EF-Tu from Agrobacterium tumefaciens (Atu) is well recognized by EFR, while EF-Tu from Pseudomonas syringae pv. tomato (Pto) DC3000 is poorly recognized. To test whether this contributes to virulence of these pathogens, we generated mutant strains that expressed EF-Tu derivatives that resembled each other’s EF-Tu. We found that when P. syringae had Agrobacterium-like EF-Tu, its growth in Arabidopsis was inhibited because of an increased pattern-triggered immunity. When A. tumefaciens had P. syringae’s EF-Tu, it caused a higher efficiency of GUS transformation in Arabidopsis. These results show that P. syringae can be restricted by EFR-dependent immune responses and support that it evades plant immunity by evolutionarily altering its EF-Tu. Conversely, our work shows that A. tumefaciens is restricted by its EF-Tu and when it expresses P. syringae like EF-Tu, it can inject more T-DNA into Arabidopsis. These modified Agrobacterium strains may be useful to researchers for Agrobacterium-mediated transit expression in Arabidopsis.

Abstract Number: P7-220
Session Type: Poster