Herbicide-induced oxidative stress in photosystem II.
Some herbicides act by binding to the exchangeable quinone site in the photosystem II (PSII) reaction centre, thus blocking electron transfer. In this article, it is hypothesized that the plant is killed by light-induced oxidative stress initiated by damage caused by formation of singlet oxygen in the reaction centre itself. This occurs when light-induced charge pairs in herbicide-inhibited PSII decay by a charge recombination route involving the formation of a chlorophyll triplet state that is able to activate oxygen. The binding of phenolic herbicides favours this pathway, thus increasing the efficiency of photodamage in this class of herbicides.
Rutherford
A W
AW
Section de Bioénergétique, DBCM, CEA CNRS URA 2096, CE Saclay, 91191, Gif-sur-Yvette, France. rutherford@dsvidf.cea.fr
Krieger-Liszkay
A
A
D000222:Adaptation, Physiological; D000458:Cyanobacteria / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D056890:Eukaryota / Q000378:metabolism; D006540:Herbicides / Q000493:pharmacokinetics / Q000494:pharmacology*; D008027:Light / Q000009:adverse effects*; D045342:Light-Harvesting Protein Complexes; D008956:Models, Chemical; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000378:metabolism; D017785:Photons / Q000009:adverse effects; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D045332:Photosystem II Protein Complex; D010944:Plants / Q000378:metabolism; D010971:Plastoquinone / Q000378:metabolism; D013816:Thermodynamics
D006540:Herbicides; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010971:Plastoquinone; D010100:Oxygen