The cyanobacteriumSynechococcusmodulates Photosystem II function in response to excitation stress through D1 exchange
✍ Scribed by Gunnar Öquist; Douglas Campbell; Adrian K. Clarke; Petter Gustafsson
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 724 KB
- Volume
- 46
- Category
- Article
- ISSN
- 0166-8595
No coin nor oath required. For personal study only.
✦ Synopsis
In this minireview we discuss effects of excitation stress on the molecular organization and function of PS II as induced by high light or low temperature in the cyanobacterium Synechococcus sp. PCC 7942. Synechococcus displays PS II plasticity by transiently replacing the constitutive D1 form (D 1:1) with another form (D 1:2) upon exposure to excitation stress. The cells thereby counteract photoinhibition by increasing D 1 turn over and modulating PS II function. A comparison between the cyanobacterium Synechococcus and plants shows that in cyanobacteria, with their large phycobilisomes, resistance to photoinhibition is mainly through the dynamic properties ( D I turnover and quenching) of the reaction centre. In contrast, plants use antenna quenching in the light-harvesting complex as an important means to protect the reaction center from excessive excitation.