Work

Ferredoxin-quinone reductase benefits cyclic electron flow around photosystem 1 in tobacco leaves upon exposure to chilling stress under low irradiance

Year: 2006

Type: article

Abstract: The function of chloroplast ferredoxin quinone reductase (FQR)-dependent flow was examined by comparing a wild type tobacco and a tobacco transformant (ΔndhB) in which the ndhB gene had been disrupted with their antimycin A (AA)-fed leaves upon exposure to chilling temperature (4 Â°C) under low irradiance (100 µmol m-2 s-1 photon flux density). During the chilling stress, the maximum photochemical efficiency of photosystem (PS) 2 (Fv/Fm) decreased markedly in both the controls and AA-fed leaves, and P700+ was also lower in AA-fed leaves than in the controls, implying that FQR-dependent cyclic electron flow around PS1 functioned to protect the photosynthetic apparatus from chilling stress under low irradiance. Under such stress, non-photochemical quenching (NPQ), particularly the fast relaxing NPQ component (qf) and the de-epoxidized ratio of the xanthophyll cycle pigments, (A+Z)/(V+A+Z), formed the difference between AA-fed leaves and controls. The lower NPQ in AA-fed leaves might be related to an inefficient proton gradient across thylakoid membranes (ΔpH) because of inhibiting an FQR-dependent cyclic electron flow around PS1 at chilling temperature under low irradiance.

Source: Photosynthetica

DOI: 10.1007/s11099-006-0035-4

Authors: X. G. Li, P. L. Xu, J. P. Zhao, J. J. Meng, Q. W. He

Institution: Shandong Academy of Agricultural Sciences

Language: English

Topic: Photosynthetic Processes and Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: bronze

Funder: National Natural Science Foundation of China