title: Salicylic acid regulates Plasmodesmata closure during innate immune responses in Arabidopsis.
abstract: In plants, mounting an effective innate immune strategy against microbial pathogens involves triggering local cell death within infected cells as well as boosting the immunity of the uninfected neighboring and systemically located cells. Although not much is known about this, it is evident that well-coordinated cell-cell signaling is critical in this process to confine infection to local tissue while allowing for the spread of systemic immune signals throughout the whole plant. In support of this notion, direct cell-to-cell communication was recently found to play a crucial role in plant defense. Here, we provide experimental evidence that salicylic acid (SA) is a critical hormonal signal that regulates cell-to-cell permeability during innate immune responses elicited by virulent bacterial infection in Arabidopsis thaliana. We show that direct exogenous application of SA or bacterial infection suppresses cell-cell coupling and that SA pathway mutants are impaired in this response. The SA- or infection-induced suppression of cell-cell coupling requires an enhanced desease resistance1- and nonexpressor of pathogenesis-related genes1-dependent SA pathway in conjunction with the regulator of plasmodesmal gating Plasmodesmata-located protein5. We discuss a model wherein the SA signaling pathway and plasmodesmata-mediated cell-to-cell communication converge under an intricate regulatory loop.
authors.affiliation: Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, Delaware 19711, USA.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Ross
authors.initials: R
authors.lastname: Sager
authors.forename: Weier
authors.initials: W
authors.lastname: Cui
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Lu
authors.forename: Jung-Youn
authors.initials: JY
authors.lastname: Lee
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001419:Bacteria / Q000254:growth & development; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D031425:Plasmodesmata / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020156:Salicylic Acid / Q000494:pharmacology*; D015398:Signal Transduction / Q000235:genetics
chemical_list: D000890:Anti-Infective Agents; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C118837:EDS1 protein, Arabidopsis; D008565:Membrane Proteins; C105496:NPR1 protein, Arabidopsis; C586778:PDLP5 protein, Arabidopsis; D019751:Intramolecular Transferases; C058486:isochorismate synthase; D020156:Salicylic Acid