Impact of UV-B radiation on uptake of 15N-ammonia and 15N-nitrate by phytoplankton of the Wadden Sea |
| |
Authors: | G Döhler |
| |
Institution: | (1) Botanisches Institut, Universität Frankfurt am Main, Siesmayerstr. 70, W-6000 Frankfurt a. M., Germany |
| |
Abstract: | Natural marine phytoplankton populations from the German Wadden Sea and unialgal cultures of the haptophycean Phaeocystis pouchetii were tested in 1989 under controlled UV-B stress conditions. Assimilation of 15N-nitrate in phytoplankton consisting mainly of P. pouchetii, or in pure cultures of this alga, was found to be very sensitive to enhanced UV-B dosage in comparison 15N-ammonia uptake. In contrast, in phytoplankton samples containing Ceratium spp., Coscinodiscus sp., Noctiluca sp. or others, rate of 15NO3
- uptake was higher and only slightly affected by UV-B irradiance compared to the P. pouchetii sample. UV-B inhibitory effect on uptake of inorganic nitrogen by P. pouchetii was more pronounced under strong white-light conditions and after a UV-B pre-illumination period of several hours than under low white light. Pools of glutamine and alanine decreased after UV-B exposure. Results are discussed with reference to the damaging effects of white light and UV-B on nitrogen metabolism. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|