title: Extracellular ATP is a regulator of pathogen defence in plants.
abstract: In healthy plants extracellular ATP (eATP) regulates the balance between cell viability and death. Here we show an unexpected critical regulatory role of eATP in disease resistance and defensive signalling. In tobacco, enzymatic depletion of eATP or competition with non-hydrolysable ATP analogues induced pathogenesis-related (PR) gene expression and enhanced resistance to tobacco mosaic virus and Pseudomonas syringae pv. tabaci. Artificially increasing eATP concentrations triggered a drop in levels of the important defensive signal chemical salicylic acid (SA) and compromised basal resistance to viral and bacterial infection. Inoculating tobacco leaf tissues with bacterial pathogens capable of activating PR gene expression triggered a rapid decline in eATP. Conversely, inoculations with mutant bacteria unable to induce defence gene expression failed to deplete eATP. Furthermore, a collapse in eATP concentration immediately preceded PR gene induction by SA. Our study reveals a previously unsuspected role for eATP as a negative regulator of defensive signal transduction and demonstrates its importance as a key signal integrating defence and cell viability in plants.
authors: Creative Gene Technology Ltd, The Integrative Cell Biology Laboratory, Durham University, Durham DH1 3LE, UK.
authors: Stephen
authors: S
authors: Chivasa
authors: Alex M
authors: AM
authors: Murphy
authors: John M
authors: JM
authors: Hamilton
authors: Keith
authors: K
authors: Lindsey
authors: John P
authors: JP
authors: Carr
authors: Antoni R
authors: AR
authors: Slabas
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010935:Plant Diseases / Q000276:immunology*; D044224:Pseudomonas syringae / Q000502:physiology*; D020156:Salicylic Acid / Q000276:immunology; D014026:Nicotiana / Q000276:immunology* / Q000378:metabolism* / Q000382:microbiology / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000502:physiology*
chemical_list: D000255:Adenosine Triphosphate; D020156:Salicylic Acid