Direct effects of UV-B radiation on the freshwater heterotrophic nanoflagellate Paraphysomonas sp.

ABSTRACT: The formation of DNA photoproducts in organisms exposed to ambient levels of UV-B radiation can lead to death and/or reduced population growth in aquatic systems. Dependence on photoenzymatic repair to reverse DNA damage caused by UV-B radiation is demonstrated for Paraphysomonas sp., a member of a widely distributed genus of heterotrophic nanoflagellates. At 20 degrees C, Paraphysomonas sp. was exposed to a range of UV-B intensities encountered in natural systems. Populations of the flagellate survived and grew in a dose-dependent manner, but only when simultaneously exposed to photorepair radiation (PRR). In contrast, flagellates exposed to UV-B at 15 degrees C suffered 100% mortality except at the lowest UV-B level (with PRR) tested, which suggested a photorepair temperature optimum abo

SUBMITTER: Macaluso AL 

PROVIDER: S-EPMC2704802 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature