The role of inactive photosystem–II–mediated quenching in a last–ditch community defence against high light stressin vivo
| العنوان: | The role of inactive photosystem–II–mediated quenching in a last–ditch community defence against high light stressin vivo |
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| المؤلفون: | Hae Youn Lee, Yong–Mok Park, Youn-Il Park, Yong–Nam Hong, Wah Soon Chow, Jan M. Anderson |
| المصدر: | Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences. 357:1441-1450 |
| بيانات النشر: | The Royal Society, 2002. |
| سنة النشر: | 2002 |
| مصطلحات موضوعية: | Photoinhibition, Light, Photosystem II, Photosynthetic Reaction Center Complex Proteins, chemistry.chemical_element, macromolecular substances, Biology, Photosynthesis, Oxygen, General Biochemistry, Genetics and Molecular Biology, Botany, Plant Physiological Phenomena, Plant Diseases, Quenching (fluorescence), food and beverages, Photosystem II Protein Complex, Plant physiology, Hydrogen-Ion Concentration, Plant disease, Kinetics, Energy Transfer, chemistry, Photoprotection, Biophysics, General Agricultural and Biological Sciences, Research Article |
| الوصف: | Photoinactivation of photosystem II (PSII), the light–induced loss of ability to evolve oxygen, is an inevitable event during normal photosynthesis, exacerbated by saturating light but counteracted by repair via new protein synthesis. The photoinactivation of PSII is dependent on the dosage of light: in the absence of repair, typically one PSII is photoinactivated per 107photons, although the exact quantum yield of photoinactivation is modulated by a number of factors, and decreases as fewer active PSII targets are available. PSII complexes initially appear to be photoinactivated independently; however, when less than 30% functional PSII complexes remain, they seem to be protected by strongly dissipative PSII reaction centres in several plant species examined so far, a mechanism which we term ‘inactive PSII–mediated quenching‘. This mechanism appears to require a pH gradient across the photosynthetic membrane for its optimal operation. The residual fraction of functional PSII complexes may, in turn, aid in the recovery of photoinactivated PSII complexes when conditions become less severe. This mechanism may be important for the photosynthetic apparatus in extreme environments such as those experienced by over–wintering evergreen plants, desert plants exposed to drought and full sunlight and shade plants in sustained sunlight. |
| تدمد: | 1471-2970 0962-8436 |
| DOI: | 10.1098/rstb.2002.1145 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f78901f80bad08d7fa0964f6e82fa7d1 https://doi.org/10.1098/rstb.2002.1145 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....f78901f80bad08d7fa0964f6e82fa7d1 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14712970 09628436 |
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| DOI: | 10.1098/rstb.2002.1145 |