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Extracellular ATP is a regulator of pathogen defence in plants
Author(s) -
Chivasa Stephen,
Murphy Alex M.,
Hamilton John M.,
Lindsey Keith,
Carr John P.,
Slabas Antoni R.
Publication year - 2009
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2009.03968.x
Subject(s) - biology , pseudomonas syringae , mutant , regulator , extracellular , microbiology and biotechnology , signal transduction , gene , pathogen , genetics
Summary 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.