Anion channel activity is necessary to induce ethylene synthesis and programmed cell death in response to oxalic acid.
Oxalic acid is thought to be a key factor of the early pathogenicity stage in a wide range of necrotrophic fungi. Studies were conducted to determine whether oxalate could induce programmed cell death (PCD) in Arabidopsis thaliana suspension cells and to detail the transduction of the signalling pathway induced by oxalate. Arabidopsis thaliana cells were treated with millimolar concentrations of oxalate. Cell death was quantified and ion flux variations were analysed from electrophysiological measurements. Involvement of the anion channel and ethylene in the signal transduction leading to PCD was determined by using specific inhibitors. Oxalic acid induced a PCD displaying cell shrinkage and fragmentation of DNA into internucleosomal fragments with a requirement for active gene expression and de novo protein synthesis, characteristic hallmarks of PCD. Other responses generally associated with plant cell death, such as anion effluxes leading to plasma membrane depolarization, mitochondrial depolarization, and ethylene synthesis, were also observed following addition of oxalate. The results show that oxalic acid activates an early anionic efflux which is a necessary prerequisite for the synthesis of ethylene and for the PCD in A. thaliana cells.
Errakhi
Rafik
R
LEM (EA 3514), Université Paris Diderot, 2 place Jussieu, 75251 Paris cedex 05, France.
Meimoun
Patrice
P
Lehner
Arnaud
A
Vidal
Guillaume
G
Briand
Joël
J
Corbineau
Françoise
F
Rona
Jean-Pierre
JP
Bouteau
François
F
D017360:Arabidopsis / Q000502:physiology*; D016923:Cell Death; D005030:Ethylenes / Q000096:biosynthesis*; D007473:Ion Channels / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D019815:Oxalic Acid / Q000378:metabolism*; D015398:Signal Transduction
D005030:Ethylenes; D007473:Ion Channels; C036216:ethylene; D019815:Oxalic Acid