In tomato, resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) is determined by the intracellular nucleotide-binding oligomerization domain (NOD)-like immune receptor (NLR) Pseudomonas resistance and fenthion sensitivity (Prf). The activation of Prf depends on perception of Pst-secreted effectors AvrPto or AvrPtoB by the Pto kinase that is physically associated with Prf. Recent studies have shown that the Pto/Prf receptor complex interacts with helper NLRs, NLR-Required for Cell death 2 (Nrc2) and Nrc3, as well as 14-3-3 proteins, tomato 14-3-3 protein 1 (Tft1) and Tft3, to activate the MAPK pathway and trigger hypersensitive response (HR) cell death. However, the direct role for Prf in transcriptional reprogramming remains largely unknown. We found that activated Prf interacts with and stabilizes the defense-related transcription factor NAM, ATAF1/2, and CUC2 (SlNAC1), which otherwise is highly unstable due to ubiquitin ligase Seven in absentia (SlSINA3)-dependent ubiquitin-proteasome-mediated degradation. Importantly, binding of activated Prf to SlNAC1 sequesters SlNAC1 from SlSINA3, thereby preventing SlNAC1 ubiquitination, which leads to enhanced transcriptional potential of SlNAC1. Moreover, SlNAC1 directly regulates the expression of pathogenesis-related (PR) genes and acts as a positive regulator in immune signaling in tomato, as shown by enhanced resistance to Pst in transgenic tomato plants overexpressing SlNAC1. Our findings reveal a mechanism utilized by an NLR protein to activate immune signaling via manipulation of a defense-related transcription factor.
- NOD-like immune receptor Prf prevents ubiquitin-proteasome-mediated degradation of the defense-related transcription factor SlNAC1
- Xiangli Niu - Hefei University of TechnologyJoanna Kud - University of Arkansas at FayettevilleYulin Yuan - University of IdahoHan Lu - University of IdahoWenjie Wang - Anhui Agricultural UniversityYouhong Fan - Department of Plant Sciences, University of Idaho, Moscow, ID, U.S.A, 83844Li Huang - University of IdahoXinran Du - University of IdahoMin Miao - Hefei University of TechnologyMadigan Eckels - University of IdahoNing Zhang - James Madison UniversityGregory B Martin - Cornell UniversityYongsheng Liu - Anhui Agricultural UniversityFangming Xiao - University of Idaho
- Plant physiology (Bethesda)
- Oxford University Press
- 996973292201851
- Plant Sciences
- English
- Journal article