Adducts of oxylipin electrophiles to glutathione reflect a 13 specificity of the downstream lipoxygenase pathway in the tobacco hypersensitive response.
The response to reactive electrophile species (RES) is now considered as part of the plant response to pathogen and insect attacks. Thanks to a previously established high-performance liquid chromatography tandem mass spectrometry methodology, we have investigated the production of oxylipin RES adducts to glutathione (GSH) during the hypersensitive response (HR) of plants. We have observed that RES conjugation to GSH in tobacco (Nicotiana tabacum) leaves is facile and nonspecific. In cryptogein-elicited tobacco leaves, we show that the oxylipin RES adducts to GSH are produced in correlation with GSH consumption, increase in glutathione S-transferase activity, and the appearance of the cell death symptoms. In this model, the adducts arise mainly from the downstream 13 lipoxygenase (LOX) metabolism, although the induced 9 LOX pathway leads massively to the accumulation of upstream metabolites. The main adducts were obtained from 2-hexenal and 12-oxo-phytodienoic acid. They accumulate transiently as 1-hexanol-3-GSH, a reduced adduct, and 12-oxo-phytodienoic acid-GSH, respectively. RES conjugation does not initiate cell death but explains part of the GSH depletion that accompanies HR cell death. The nature of these GSH conjugates shows the key role played by the 13 LOX pathway in RES signaling in the tobacco HR.
Davoine
Céline
C
Laboratoire de Radiobiologie Végétale, DSV-Département d'Ecophysiologie Végétale et de Microbiologie, CEA-Cadarache, 13108 Saint-Paul Lez Durance cedex, France.
Falletti
Olivier
O
Douki
Thierry
T
Iacazio
Gilles
G
Ennar
Najla
N
Montillet
Jean-Luc
JL
Triantaphylidès
Christian
C
D000171:Acrolein / Q000494:pharmacology; D000447:Aldehydes / Q000494:pharmacology; D017209:Apoptosis; D002074:Butanones / Q000494:pharmacology; D005978:Glutathione / Q000737:chemistry* / Q000378:metabolism; D007113:Immunity, Innate; D050356:Lipid Metabolism; D008084:Lipoxygenase / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism
D000447:Aldehydes; D002074:Butanones; D010940:Plant Proteins; C013166:2-nonenal; C051750:2-hexenal; D000171:Acrolein; C057920:3-buten-2-one; C117433:13-lipoxygenase; D008084:Lipoxygenase; D005978:Glutathione