title: Temperature-dependent formation and photorepair of DNA damage induced by UV-B radiation in suspension-cultured tobacco cells.
abstract: Two photoproducts of DNA damage, i.e. cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs), induced by UV-B radiation in suspension-cultured tobacco cells were quantified by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. CPDs and 6-4PPs were induced in tobacco cells by UV-B radiation. Photorepair of CPDs was faster than that of 6-4PPs. UV-B radiation induces formation of CPDs and 6-4PPs even at 0 degrees C, but low temperature significantly decreases the UV-B-induced (in contrast to UV-C-induced) formation of CPDs and 6-4PPs. Low temperature also retarded the removal of CPDs and 6-4PPs under white light, and almost no photorepair of CPDs and 6-4PPs was detected at 0 degrees C. When purified DNA from tobacco cells grown in darkness was irradiated with UV-B, formation of CPDs and 6-4PPs took place at the same speed at different temperatures. It indicated that formation of CPDs and 6-4PPs induced by UV-B was temperature-independent in a non-cellular system. Based on our results for suspension-cultured tobacco cells, not only the photorepair but also UV-B-induced formation of CPDs and 6-4PPs are temperature-dependent.
authors.affiliation: Department of Plant Physiology, Lund University, Box 117, SE-221 00 Lund, Sweden. lishsh@scnu.edu.cn
authors.forename: Shaoshan
authors.initials: S
authors.lastname: Li
authors.forename: Markus
authors.initials: M
authors.lastname: Paulsson
authors.forename: Lars Olof
authors.initials: LO
authors.lastname: Björn
mesh_terms: D002478:Cells, Cultured; D004249:DNA Damage / Q000528:radiation effects*; D004260:DNA Repair / Q000528:radiation effects*; D018744:DNA, Plant / Q000528:radiation effects; D011740:Pyrimidine Dimers / Q000096:biosynthesis; D013696:Temperature; D014026:Nicotiana / Q000166:cytology*; D014466:Ultraviolet Rays
chemical_list: D018744:DNA, Plant; D011740:Pyrimidine Dimers; C058406:pyrimidine-pyrimidone dimer