| Title: | "Alteration of foliar flavonoid chemistry induced by enhanced UV-B radiation in field-grown Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii" |
| Author(s): | Warren JM; Bassman JH; Mattinson DS; Fellman JK; Edwards GE; Robberecht R; |
| Address: | "Department of Natural Resource Sciences, Washington State University, Pullman, WA 99164-6410, USA" |
| DOI: | 10.1016/s1011-1344(02)00230-0 |
| ISSN/ISBN: | 1011-1344 (Print) 1011-1344 (Linking) |
| Abstract: | "Chromatographic analyses of foliage from several tree species illustrate the species-specific effects of UV-B radiation on both quantity and composition of foliar flavonoids. Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii were field-grown under modulated ambient (1x) and enhanced (2x) biologically effective UV-B radiation. Foliage was harvested seasonally over a 3-year period, extracted, purified and the flavonoid fraction applied to a mu Bondapak/C(18) column HPLC system sampling at 254 nm. Total flavonoid concentrations in Quercus rubra foliage were more than twice (leaf area basis) that of the other species; Pseudotsuga menziesii foliage had intermediate levels and P. ponderosa had the lowest concentrations of total flavonoids. No statistically significant UV-B radiation-induced effects were found in total foliar flavonoid concentrations for any species; however, concentrations of specific compounds within each species exhibited significant treatment effects. Higher (but statistically insignificant) levels of flavonoids were induced by UV-B irradiation in 1- and 2-year-old P. ponderosa foliage. Total flavonoid concentrations in 2-year-old needles increased by 50% (1x ambient UV-B radiation) or 70% (2x ambient UV-B radiation) from that of 1-year-old tissue. Foliar flavonoids of Q. rubra under enhanced UV-B radiation tended to shift from early-eluting compounds to less polar flavonoids eluting later. There were no clear patterns of UV-B radiation effects on 1-year-old P. menziesii foliage. However, 2-year-old tissue had slightly higher foliar flavonoids under the 2x UV-B radiation treatment compared to ambient levels. Results suggest that enhanced UV-B radiation will alter foliar flavonoid composition and concentrations in forest tree species, which could impact tissue protection, and ultimately, competition, herbivory or litter decomposition" |
| Keywords: | Flavins/*metabolism Pinus/metabolism/*radiation effects Pinus ponderosa Plant Leaves/metabolism/radiation effects Pseudotsuga/metabolism/*radiation effects Ultraviolet Rays; |
| Notes: | "MedlineWarren, Jeffrey M Bassman, John H Mattinson, D Scott Fellman, John K Edwards, Gerald E Robberecht, Ronald eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Switzerland 2002/03/19 J Photochem Photobiol B. 2002 Mar; 66(2):125-33. doi: 10.1016/s1011-1344(02)00230-0" |
