Chlorophyll Photobleaching is Dependent on Photosystem II Inhibition

Abstract

Exposure of leaves, algal cells or isolated chloroplasts, to high light intensities results in marked decreases in their photosynthetic activity (see ref. [1] and [2] for reviews). Two distinct processes can be identified, photoinhibition and photobleaching. Photoinhibition is an oxygen-independent inhibition of PSII activity involving the degradation of the Q,-binding protein located close to the PSII reaction centre [3]. Photobleaching, in contrast, involves an oxygen-dependent loss of bulk photosynthetic pigment.