title: Nitric oxide and reactive oxygen species are required for systemic acquired resistance in plants.
abstract: Systemic acquired resistance (SAR) is a form of broad-spectrum disease resistance that is induced in response to primary infection and that protects uninfected portions of the plant against secondary infections by related or unrelated pathogens. SAR is associated with an increase in chemical signals that operate in a collective manner to confer protection against secondary infections. These include, the phytohormone salicylic acid (SA), glycerol-3-phosphate (G3P), azelaic acid (AzA) and more recently identified signals nitric oxide (NO) and reactive oxygen species (ROS). NO, ROS, AzA and G3P function in the same branch of the SAR pathway, and in parallel to the SA-regulated branch. NO and ROS function upstream of AzA/G3P and different reactive oxygen species functions in an additive manner to mediate chemical cleavage of the C9 double bond on C18 unsaturated fatty acids to generate AzA. The parallel and additive functioning of various chemical signals provides important new insights in the overlapping pathways leading to SAR.
authors.affiliation: a Department of Plant Pathology ; University of Kentucky ; Lexington , KY USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Shetehy
authors.affiliation: a Department of Plant Pathology ; University of Kentucky ; Lexington , KY USA.
authors.forename: Caixia
authors.initials: C
authors.lastname: Wang
authors.affiliation: a Department of Plant Pathology ; University of Kentucky ; Lexington , KY USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Shine
authors.affiliation: a Department of Plant Pathology ; University of Kentucky ; Lexington , KY USA.
authors.forename: Keshun
authors.initials: K
authors.lastname: Yu
authors.affiliation: a Department of Plant Pathology ; University of Kentucky ; Lexington , KY USA.
authors.forename: Aardra
authors.initials: A
authors.lastname: Kachroo
authors.affiliation: a Department of Plant Pathology ; University of Kentucky ; Lexington , KY USA.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kachroo
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000378:metabolism; D060467:Disease Resistance / Q000276:immunology*; D008954:Models, Biological; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D044224:Pseudomonas syringae; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C521947:NOA1 protein, Arabidopsis; D019001:Nitric Oxide Synthase
keywords: free radicals, glycerol-3-phosphate, nitric oxide, plant defense, reactive oxgyen species, systemic acquired resistance