| Author/Editor | Rozema, J; Bjoern, LO; Bornman, JF; Gaberščik, A; Haeder, D-P; Trošt, T; Germ, M; Klisch, M; Groeniger, A; Sinha, RP | |
| Title | The role of UV-B radiation in aquatic and terrestial ecosystems - an experimental and functional analysis of the evolution of UV-absorbing compounds | |
| Type | članek | |
| Source | J Photochem Photobiol B | |
| Vol. and No. | Letnik 66, št. 1 | |
| Publication year | 2002 | |
| Volume | str. 2-12 | |
| Language | eng | |
| Abstract | We analysed and compared the functioning of UV B screening pigments in plants from marine, fresh water and terrestrial ecosystems, along the evolutionary lime of cyanobacteria, unicellular algae, primitive multicellular algae, charophycean algae, lichens, mosses and higher plants, including amphibious macrophytes. Lichens were also included in the study. We were interested in the following key aspects: (a) does thd water column function effectively as an 'external UV B filter'?; (b) do aquatic plants need less žinternal UV B screening' than terrestrial plants?; (c) what role does UV screening play in protecting the various plant groups from UV B damage, such as the formation of thymine dimers?; and (d) since early land 'plants' (such as the predecessors of present-day cyanobacteria, lichens and mosses) experienced higher UV B fluxes than higher plants, which evolved later, are primitive aquatic and land organisms (cyanobacteria, algae, lichens, mosses) better adapted to present-day levels of UV B than higher plants? Furthermore, polychromatic action spectra for the induction of UV screening pigments of aquatic organisms have been determined. This is relevant for translating 'physical' radiation measurements of solar UV B into 'biological' and 'ecological' effects. From the action spectra, radiation amplification factors (RAFs) have been calculated. These action spectra allow us to determine any mitigating or antagonistic effects in the ecosystems and therefore qualify the damage prediction for the ecosystems under study. We summarize and discuss the main results based on three years of research of four European research groups. (Abstract truncated at 2000 characters) | |
| Descriptors | PLANTS ECOSYSTEM ULTRAVIOLET RAYS FLAVONES OZONE ALGAE CYANOBACTERIA LICHENS MOSSES QUERCETIN |