title: Induction of the synthesis of an UV-absorbing substance in the green alga Prasiola stipitata.
abstract: The chlorophyte Prasiola stipitata produces a UV-absorbing substance with an absorption maximum at 324 nm. The wavelength-dependent induction of the synthesis of this substance was investigated using simulated solar radiation in combination with 15 cut-off and one broad-band filter. The algae were exposed from three different distances (89, 100 and 119 cm) to the solar simulator producing a maximum of 203.58, 1.24 and 46.86 W/m(2) and a minimum of 107.94, 0.64 and 24.44 W/m(2) irradiances for PAR, UV-B and UV-A, respectively. A polychromatic action spectrum was calculated from the pooled results showing a clear maximum at 300 nm in the long-wavelength UV-B range, but there is still some induction caused by UV-A and PAR. The ratio of the effectiveness from PAR to UV-A to UV-B amounts to 1:2:22.
authors.affiliation: Institut für Botanik und Pharmazeutische Biologie, Friedrich-Alexander Universität Erlangen-Nürnberg, Staudtstr. 5, D-91058 Erlangen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gröniger
authors.forename: D-P
authors.initials: DP
authors.lastname: Häder
mesh_terms: D002457:Cell Extracts / Q000737:chemistry / Q000528:radiation effects; D000460:Chlorophyta / Q000737:chemistry / Q000254:growth & development / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D013054:Spectrophotometry, Atomic; D014466:Ultraviolet Rays
chemical_list: D002457:Cell Extracts