How do environmental stresses accelerate photoinhibition?
Environmental stress enhances the extent of photoinhibition, a process that is determined by the balance between the rate of photodamage to photosystem II (PSII) and the rate of its repair. Recent investigations suggest that exposure to environmental stresses, such as salt, cold, moderate heat and oxidative stress, do not affect photodamage but inhibit the repair of PSII through suppression of the synthesis of PSII proteins. In particular, production of D1 protein is downregulated at the translation step by the direct inactivation of the translation machinery and/or by primarily interrupting the fixation of CO2. The latter results in the creation of reactive oxygen species (ROS), which in turn block the synthesis of PSII proteins in chloroplasts.
Takahashi
Shunichi
S
Molecular Plant Physiology Group and Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biological Sciences, Australian National University, PO Box 475, Canberra, ACT 0200, Australia.
Murata
Norio
N
D002245:Carbon Dioxide / Q000378:metabolism; D008027:Light; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology / Q000528:radiation effects*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D010944:Plants / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D002245:Carbon Dioxide