title: Solar ultraviolet-B radiation increases phenolic content and ferric reducing antioxidant power in Avena sativa.
abstract: We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm) on the maximum photochemical efficiency of photosystem II (F(v)/F(m)), bulk-soluble phenolic concentrations, ferric-reducing antioxidant power (FRAP) and growth of Avena sativa. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B by either 71% (reduced UV-B) or by 19% (near-ambient UV-B) over the 52 day experiment (04 July-25 August 2002). Plants growing under near-ambient UV-B had 38% less total biomass than those under reduced UV-B. The reduction in biomass was mainly the result of a 24% lower leaf elongation rate, resulting in shorter leaves and less total leaf area than plants under reduced UV-B. In addition, plants growing under near-ambient UV-B had up to 17% lower F(v)/F(m) values early in the experiment, and this effect declined with plant age. Concentrations of bulk-soluble phenolics and FRAP values were 17 and 24% higher under near-ambient UV-B than under reduced UV-B, respectively. There was a positive relationship between bulk-soluble phenolic concentrations and FRAP values. There were no UV-B effects on concentrations of carotenoids (carotenes + xanthophylls).
authors: Department of Biological Sciences, TS-242 Trafton Sciences Center, Minnesota State University, Mankato, MN 56001, USA. christopher.ruhland@mnsu.edu
authors: Christopher T
authors: CT
authors: Ruhland
authors: Mitchell J
authors: MJ
authors: Fogal
authors: Christopher R
authors: CR
authors: Buyarski
authors: Matthew A
authors: MA
authors: Krna
mesh_terms: D000975:Antioxidants / Q000528:radiation effects*; D018554:Avena / Q000378:metabolism / Q000528:radiation effects; D005290:Ferric Compounds; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis* / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000528:radiation effects; D013472:Sunlight; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D005290:Ferric Compounds; D010636:Phenols; D045332:Photosystem II Protein Complex