The chloroplast Ndh complex mediates the dark reduction of the plastoquinone pool in response to heat stress in tobacco leaves

FEBS Letters

Nixon, Peter J¹  Sazanov, Leonid A¹  Burrows, Paul A¹ 

[1] Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK

关键词: ndh;    Chloroplast;    Plastoquinone;    Chlororespiration;    Heat stress;    Cyclic electron flow;    F o;    minimum level of chlorophyll fluorescence when PSII centres are open;    F m;    maximum level of chlorophyll fluorescence when PSII centres are closed;   

DOI  :  10.1016/S0014-5793(98)00573-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have examined the effects of heat stress on electron transfer in the thylakoid membrane of an engineered plastid ndh deletion mutant, Δ1, incapable of performing the Ndh-mediated reduction of the plastoquinone pool in the chloroplast. Upon heat stress in the dark, the rate of PSII-independent reduction of PSI after subsequent illumination by far-red light is dramatically enhanced in both Δ1 and a wild-type control plant (WT). In contrast, in the dark, only the WT shows an increase in the reduction state of the plastoquinone pool. We conclude that the heat stress-induced reduction of the intersystem electron transport chain can be mediated by Ndh-independent pathways in the light but that in the dark the dominant pathway for reduction of the plastoquinone pool is catalysed by the Ndh complex. Our results therefore demonstrate a functional role for the Ndh complex in the dark.

【 授权许可】

Unknown