Singlet oxygen production in herbicide‐treated photosystem II

FEBS Letters

Krieger-Liszkay, Anja²  Fufezan, Christian²  Rutherford, A.William¹ 

[1] Service de Bioénergétique, DBJC, CNRS URA 2096, CEA Saclay, 91191 Gif-sur-Yvette, France;Institut für Biologie II, Biochemie der Pflanzen, Universität Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany

关键词: Photosystem II;    Oxidative stress;    Herbicide;    Charge recombination;    Singlet oxygen;    Chl;    chlorophyll;    DCMU;    3-(3;    4-dichlorophenyl)-1;    1-dimethylurea;    EMPO;    2-ethoxycarbonyl-2-methyl-3;    4-dihydro-2H-pyrrole-1-oxide;    PSII;    photosystem II;    QA;    primary quinone electron acceptor in PSII;    QB;    secondary quinone electron acceptor in PSII;    Pheo;    pheophytin – primary electron acceptor;    PPBQ;    phenyl-p-benzoquinone;    SOD;    superoxide dismutase;    TEMP;    2;    2;    6;    6-tetramethylpiperidine;    TEMPO;    2;    2;    6;    6-tetramethylpiperidine-1-oyxl;   

DOI  :  10.1016/S0014-5793(02)03724-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Photo-generated reactive oxygen species in herbicide-treated photosystem II were investigated by spin-trapping. While the production of OH and O₂ ⁻ was herbicide-independent, ¹O₂ with a phenolic was twice that with a urea herbicide. This correlates with the reported influence of these herbicides on the redox properties of the semiquinone Q_A ⁻ and fits with the hypothesis that ¹O₂ is produced by charge recombination reactions that are stimulated by herbicide binding and modulated by the nature of the herbicide. When phenolic herbicides are bound, charge recombination at the level of P⁺ Pheo⁻ is thermodynamically favoured forming a chlorophyll triplet and hence ¹O₂. With urea herbicides this pathway is less favourable.

【 授权许可】

Unknown