title: Towards elucidation of dynamic structural changes of plant thylakoid architecture.
abstract: Long-term acclimation of shade versus sun plants modulates the composition, function and structural organization of the architecture of the thylakoid membrane network. Significantly, these changes in the macroscopic structural organization of shade and sun plant chloroplasts during long-term acclimation are also mimicked following rapid transitions in irradiance: reversible ultrastructural changes in the entire thylakoid membrane network increase the number of grana per chloroplast, but decrease the number of stacked thylakoids per granum in seconds to minutes in leaves. It is proposed that these dynamic changes depend on reversible macro-reorganization of some light-harvesting complex IIb and photosystem II supracomplexes within the plant thylakoid network owing to differential phosphorylation cycles and other biochemical changes known to ensure flexibility in photosynthetic function in vivo. Some lingering grana enigmas remain: elucidation of the mechanisms involved in the dynamic architecture of the thylakoid membrane network under fluctuating irradiance and its implications for function merit extensive further studies.
authors.affiliation: Division of Plant Science, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia. jan.Anderson@anu.edu.au
authors.forename: Jan M
authors.initials: JM
authors.lastname: Anderson
authors.forename: Peter
authors.initials: P
authors.lastname: Horton
authors.forename: Eun-Ha
authors.initials: EH
authors.lastname: Kim
authors.forename: Wah Soon
authors.initials: WS
authors.lastname: Chow
mesh_terms: D000064:Acclimatization; D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects; D003624:Darkness; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism; D053141:Organelle Size; D055668:Photochemical Processes; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects*; D018724:Spinacia oleracea / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects; D020524:Thylakoids / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D013997:Time Factors
chemical_list: D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex