title: Effects of ultraviolet radiation (UVA+UVB) and copper on the morphology, ultrastructural organization and physiological responses of the red alga Pterocladiella capillacea.
abstract: The effect of ultraviolet (UV) radiation and copper (Cu) on apical segments of Pterocladiella capillacea was examined under two different conditions of radiation, PAR (control) and PAR+UVA+UVB (PAR+UVAB), and three copper concentrations, ranging from 0 (control) to 0.62, 1.25 and 2.50 μm. Algae were exposed in vitro to photosynthetically active radiation (PAR) at 70 μmol photons m(-2)  s(-1) , PAR + UVB at 0.35 W m(-2) and PAR +UVA at 0.70 W m(-2) during a 12-h photocycle for 3 h each day for 7 days. The effects of radiation and copper on growth rates, content of photosynthetic pigments and photosynthetic performance were analyzed. In addition, samples were processed for light and transmission electron microscopy. The content of photosynthetic pigments decreased after exposure to radiation and Cu. Compared with PAR radiation and copper treatments modified the kinetics patterns of the photosynthesis/irradiance curve. The treatments also caused changes in the ultrastructure of cortical and subcortical cells, including increased cell wall thickness and accumulation of plastoglobuli, as well as changes in the organization of chloroplasts. The results indicate that the synergistic interaction between UV radiation and Cu in P. capillacea, led to the failure of protective mechanisms and causing more drastic changes and cellular imbalances.
authors.affiliation: Postdoctoral Research of Postgraduate Program in Cell Biology and Development, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, Florianópolis, SC, Brazil; Department of Cell Biology, Embryology and Genetics, Plant Cell Biology Laboratory, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Éder C
authors.initials: ÉC
authors.lastname: Schmidt
authors.forename: Marianne
authors.initials: M
authors.lastname: Kreusch
authors.forename: Marthiellen R de L
authors.initials: MR
authors.lastname: Felix
authors.forename: Debora T
authors.initials: DT
authors.lastname: Pereira
authors.forename: Giulia B
authors.initials: GB
authors.lastname: Costa
authors.forename: Carmen
authors.initials: C
authors.lastname: Simioni
authors.forename: Luciane C
authors.initials: LC
authors.lastname: Ouriques
authors.forename: Francine L
authors.initials: FL
authors.lastname: Farias-Soares
authors.forename: Neusa
authors.initials: N
authors.lastname: Steiner
authors.forename: Fungyi
authors.initials: F
authors.lastname: Chow
authors.forename: Fernanda
authors.initials: F
authors.lastname: Ramlov
authors.forename: Marcelo
authors.initials: M
authors.lastname: Maraschin
authors.forename: Zenilda L
authors.initials: ZL
authors.lastname: Bouzon
mesh_terms: D002473:Cell Wall / Q000187:drug effects / Q000528:radiation effects* / Q000648:ultrastructure; D002734:Chlorophyll / Q000096:biosynthesis; D000077194:Chlorophyll A; D002736:Chloroplasts / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure; D003300:Copper / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D017785:Photons; D017440:Photoperiod; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D052979:Phycobiliproteins / Q000096:biosynthesis; D010860:Pigments, Biological / Q000096:biosynthesis; D000461:Rhodophyta / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure; D014466:Ultraviolet Rays
chemical_list: D052979:Phycobiliproteins; D010860:Pigments, Biological; D002734:Chlorophyll; D003300:Copper; C029892:cupric chloride; D000077194:Chlorophyll A