Fatty acid hydroperoxides and H2O2 in the execution of hypersensitive cell death in tobacco leaves.
We initially compared lipid peroxidation profiles in tobacco (Nicotiana tabacum) leaves during different cell death events. An upstream oxylipin assay was used to discriminate reactive oxygen species (ROS)-mediated lipid peroxidation from 9- and 13-lipoxygenase (LOX)-dependent lipid peroxidation. Free radical-mediated membrane peroxidation was measured during H(2)O(2)-dependent cell death in leaves of catalase-deficient plants. Taking advantage of these transgenic plants, we demonstrate that, under light conditions, H(2)O(2) plays an essential role in the execution of cell death triggered by an elicitor, cryptogein, which provokes a similar ROS-mediated lipid peroxidation. Under dark conditions, however, cell death induction by cryptogein was independent of H(2)O(2) and accompanied by products of the 9-LOX pathway. In the hypersensitive response induced by the avirulent pathogen Pseudomonas syringae pv syringae, both 9-LOX and oxidative processes operated concurrently, with ROS-mediated lipid peroxidation prevailing in the light. Our results demonstrate, therefore, the tight interplay between H(2)O(2) and lipid hydroperoxides and underscore the importance of light during the hypersensitive response.
Commissariat à l'Energie Atomique/Cadarache, Direction des Sciences du Vivant, Département d'Ecophysiologie Végétale et de Microbiologie, Laboratoire de Radiobiologie Végétale, F-13108 Saint-Paul-Lez-Durance cedex, France.
Jean-Luc
JL
Montillet
Sangpen
S
Chamnongpol
Christine
C
Rustérucci
James
J
Dat
Brigitte
B
van de Cotte
Jean-Pierre
JP
Agnel
Christine
C
Battesti
Dirk
D
Inzé
Frank
F
Van Breusegem
Christian
C
Triantaphylidès
D002374:Catalase / Q000235:genetics / Q000378:metabolism; D016923:Cell Death / Q000502:physiology*; D003624:Darkness; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008027:Light; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000378:metabolism*; D008084:Lipoxygenase / Q000378:metabolism; D018384:Oxidative Stress; D018515:Plant Leaves / Q000166:cytology* / Q000502:physiology; D030821:Plants, Genetically Modified; D014026:Nicotiana / Q000166:cytology* / Q000201:enzymology / Q000502:physiology
D008054:Lipid Peroxides; D006861:Hydrogen Peroxide; D002374:Catalase; C117433:13-lipoxygenase; D008084:Lipoxygenase