title: Transport of chemical signals in systemic acquired resistance.
abstract: Systemic acquired resistance (SAR) is a form of broad-spectrum resistance induced in response to local infections that protects uninfected parts against subsequent secondary infections by related or unrelated pathogens. SAR signaling requires two parallel branches, one regulated by salicylic acid (SA), and the other by azelaic acid (AzA) and glycerol-3-phosphate (G3P). AzA and G3P function downstream of the free radicals nitric oxide (NO) and reactive oxygen species (ROS). During SAR, SA, AzA and G3P accumulate in the infected leaves, but only a small portion of these is transported to distal uninfected leaves. SA is preferentially transported via the apoplast, whereas phloem loading of AzA and G3P occurs via the symplast. The symplastic transport of AzA and G3P is regulated by gating of the plasmodesmata (PD). The PD localizing proteins, PDLP1 and PDLP5, regulate SAR by regulating PD gating as well as the subcellular partitioning of a SAR-associated protein.
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Archana
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Gah-Hyun
authors.initials: GH
authors.lastname: Lim
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kachroo
mesh_terms: D017360:Arabidopsis / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D003998:Dicarboxylic Acids / Q000378:metabolism; D060467:Disease Resistance / Q000502:physiology*; D005994:Glycerophosphates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052585:Phloem / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology*; D018515:Plant Leaves / Q000378:metabolism; D031425:Plasmodesmata / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003998:Dicarboxylic Acids; D005994:Glycerophosphates; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C029620:alpha-glycerophosphoric acid; C010038:azelaic acid; D020156:Salicylic Acid