EPR measurements on the effects of bicarbonate and triazine resistance on the acceptor side of Photosystem II

FEBS Letters

Vermaas, Wim F.J.²  Rutherford, A.William¹ 

[1] Service de Biophysique, Départment de Biologie, Centre d'Etudes Nucléaires de Saclay, 91191 Gif-sur-Yvette, Cédex, France;Laboratory of Plant Physiological Research, Agricultural University, Gen. Foulkesweg 72, 6703 BW Wageningen, The Netherlands

关键词: Semiquinone-iron complex;    Photosystem II;    Bicarbonate effect;    Triazine resistance;    Photosynthesis;    Herbicide;   

DOI  :  10.1016/0014-5793(84)80744-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

CO₂ depletion leads to an approximately 10-fold increase in the light-induced EPR signal at g = 1.82, attributed to the Q_A ⁻ · Fe²⁺ complex, in Photosystem II-enriched thylakoid membrane fragments. Upon reconstitution with HCO₃ ⁻the signal decreases to the size in control samples. The split pheophytin⁻ signal is broader in control or reconstituted than in CO₂-depleted samples. It is concluded that HCO₂ ⁻ strongly influences the localization and conformation of the Q_A ⁻ · Fe⁺ complex. The Q_A ⁻ · Fe²⁺ and split pheophytirr⁻ EPR signals from triazine-resistant Brassica napus were virtually identical to those from triazine-susceptible samples, indicating that the change in the 32-kDa azidoatrazine-binding protein does not lead to a confonnational change of the Q_a ⁻ · Fe²⁺ complex.

【 授权许可】

Unknown