Tomato 14-3-3 proteins are signaling components of immunity and common targets of Xanthomonas effectors
Z. DUBROW (1), S. Sukumaran (2), J. Kim (1), D. Teper (2), E. Bosis (2), G. Sessa (2), M. Mudgett (1) (1) Stanford University, U.S.A.; (2) Tel Aviv University, Israel

The goal of this research is to identify 14-3-3 proteins that are involved in plant immunity and to determine how bacterial pathogens employ the type III secretion (T3S) system and its cognate effector proteins to manipulate their function. 14-3-3s, a class of eukaryotic phospho-binding proteins with scaffolding activity, play central roles in the assembly and disassembly of eukaryotic signaling complexes, ultimately controlling the kinetics and magnitude of cellular responses to given stimuli. Mounting evidence indicates that 14-3-3s are required for proper execution of plant immune signaling during infection. Specific 14-3-3 isoforms from various plant species have been linked to regulation of pathogen-triggered immunity (PTI) and/or effector-triggered immunity (ETI). Moreover, several T3S effectors from various bacterial pathogens have been shown to physically associate with plant and animal 14-3-3s. Taken together, these data suggest that multiple pathogens have evolved novel mechanisms to subvert and/or co-opt 14-3-3 function to promote pathogenicity. In this study, we used the Xanthomonas euvesicatoria (Xcv)-tomato pathosystem to determine the contribution of 11 tomato 14-3-3 isoforms in PTI and ETI. We also determined which Xcv T3S effectors directly interact with these isoforms. Our data indicates that multiple tomato 14-3-3 isoforms contribute to anti-Xanthomonas immunity and a small group of effectors interact with multiple 14-3-3 isoforms. These data and recent progress in understanding the impact of 14-3-3/effector complex formation on the proper execution of tomato immune responses will be discussed.

Abstract Number: P9-290
Session Type: Poster