title: Time sequence of the damage to the acceptor and donor sides of photosystem II by UV-B radiation as evaluated by chlorophyll a fluorescence.
abstract: The effects of ultraviolet-B (UV-B) radiation on photosystem II (PS II) were studied in leaves of Chenopodium album. After the treatment with UV-B the damage was estimated using chlorophyll a fluorescence techniques. Measurements of modulated fluorescence using a pulse amplitude modulated fluorometer revealed that the efficiency of photosystem II decreased both with increasing time of UV-B radiation and with increasing intensity of the UV-B. Fluorescence induction rise curves were analyzed using a mechanistic model of energy trapping. It appears that the damage by UV-B radiation occurs first at the acceptor side of photosystem II, and only later at the donor side.
authors.affiliation: Laboratory of Plant Physiology, Wageningen University and Research Center, Arboretumlaan 4, Wageningen, 6703 BD, The Netherlands. Jack.VanRensen@wur.nl
authors.forename: Jack J S
authors.initials: JJ
authors.lastname: van Rensen
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Vredenberg
authors.forename: Gustavo C
authors.initials: GC
authors.lastname: Rodrigues
mesh_terms: D027462:Chenopodium / Q000378:metabolism / Q000528:radiation effects; D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism*; D005453:Fluorescence; D010788:Photosynthesis / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D045332:Photosystem II Protein Complex; D002734:Chlorophyll