Molecular basis for the interference of the Arabidopsis WRKY54‐mediated immune response by two sequence‐unrelated bacterial effectors

• DOI: 10.1111/tpj.16639
• Publication Date: 2024-01-25T17:20:12Z
• Authors: Haseong Kim; Jieun Kim; Du Seok Choi; Min‐Sung Kim; Laurent Deslandes; Jay Jayaraman; Kee Hoon Sohn
• Keywords: WRKY protein domain; Ralstonia solanacearum; Pseudomonas syringae; Hypersensitive response

SUMMARY Arabidopsis thaliana WRKY proteins are potential targets of pathogen‐secreted effectors. RESISTANT TO RALSTONIA SOLANACEARUM 1 (RRS1; AtWRKY52) is a well‐studied nucleotide‐binding and leucine‐rich repeat (NLR) immune receptor carrying C‐terminal domain that functions as an integrated decoy. RRS1‐R recognizes the effectors AvrRps4 from Pseudomonas syringae pv. pisi PopP2 Ralstonia pseudosolanacearum by direct interaction through its domain. were previously shown to interact with several AtWRKYs. However, how these selectively their virulence remains unknown. Here, we show members subgroup IIIb AtWRKY family targeted PopP2. We demonstrate AtWRKYs induce cell death when transiently expressed in Nicotiana benthamiana , indicating activation responses. AtWRKY54 was only death‐inducing interacted both found specifically suppress AtWRKY54‐induced death. also amino acid residues required for avirulence function critical suppressing predicted form binding interface predominantly located DNA necessary inducing Notably, one residue, E164, contributes affinity exclusively present among AtWRKYs, yet outside DNA‐binding Surprisingly, mutated at E164 evaded AvrRps4‐mediated suppression. Taking our observations together, propose AvrRp4 target plant