Abstract

In addition to the energy dissipation of excess light occurring in PSII antenna via the xanthophyll cycle, there is mounting evidence of a zeaxanthin-independent pathway for non-photochemical quenching based within the PSII reaction centre (reaction centre quenching) that may also play a significant role in photo protection. it has been demonstrated that acclimation of higher plants, green algae and cyanobacteria to low temperature or high light conditions which potentially induce an imbalance between energy supply and energy utilization is accompanied by the development of higher reduction state of Q(A) and higher resistance to photoinhibition (Huner et al., 1998). Although this is a fundamental feature of all photoautotrophs, and the acquisition of increased tolerance to photoinhibition has been ascribed to growth and development under high PSII excitation pressure, the precise mechanism controlling the redox state of Q(A) and its physiological significance in developing higher resistance to photoinhibition has not been fully elucidated. In this review we summarize recent data indicating that the increased resistance to high light in a broad spectrum of photosynthetic organisms acclimated to high excitation pressure conditions is associated with an increase probability for alternative non-radiative P680(+)Q(A)(-) radical pair recombination pathway for energy dissipation within the reaction centre of PSII. The various molecular mechanisms that could account for nonphotochemical quenching through PSII reaction centre are also discussed.

Keywords

electron transport; energy dissipation; non-photochemical quenching; photoprotection; photosystem II; reaction centre quenching

Published in

Journal of Plant Biology
2008, Volume: 51, number: 2, pages: 85-96

UKÄ Subject classification

Botany


Publication identifier

DOI: https://doi.org/10.1007/BF03030716

Permanent link to this page (URI)

https://res.slu.se/id/publ/76342