PDBP1 is a novel regulator of plant elicitor peptide (PEP)-induced plant immunity
P. WECKWERTH (1), Z. Shen (2), S. Briggs (2), K. Dressano (2), A. Huffaker (1) (1) UCSD, U.S.A.; (2) UCSD, U.S.A.

Plants have evolved specialized plasma-membrane localized receptor proteins to perceive microbial pathogens, thus enabling them to respond to these environmental threats in a timely and specific manner. An early response after pathogen attack is activation of endogenous plant elicitor peptides (PEPs) to initiate a PEP?PEPR (PEP-Receptor) signaling cascade. Upon binding of the peptide to its receptor, a complex forms with additional co-receptors (e.g. BAK1) required for full signal capacity. Subsequently a signal transduction cascade is initiated and leads to phosphorylation of target proteins, resulting in altered activities of these and initiating downstream signaling events. In a phosphoproteomics screen evaluating PEP-dependent phosphorylation patterns in maize and Arabidopsis, we identified a DNA-binding protein (PDBP1) with increased phosphorylation after ZmPep3 and AtPep1 treatment, respectively. We obtained insertional mutant lines in both maize and Arabidopsis to elucidate the molecular function of this protein. Insertional mutants in Arabidopsis show hypersensitivity to AtPep1-treatment, indicating a potential role as a negative regulator. We hypothesize that PDPB1 as a DNA-binding protein modifies the plant’s immune response by regulating transcriptional responses after pathogen attack. To address our hypothesis, we have examined the early signaling events and changes in transcriptional patterns upon PEP-treatment in both maize and Arabidopsis.

Abstract Number: P17-637
Session Type: Poster