Uv-b Sensitivity of Aquatic Plants: the Impact of Artificial Ultraviolet Radiation on the Survival and Chlorophyll

Ultraviolet-B (UV-B) radiation can have wide-ranging impacts on plants. UV-B exposure can decrease the rate of photosynthesis, alter pigment concentrations, and damage DNA, proteins, and lipids; however, not all species are equally sensitive. Lemna minor and Spirodela polyrhiza, two sympatric aquatic plants, were exposed to 5 or 11 days of artificial UV-B radiation for 6 hours per day, and monitored over a 29 hour recovery period. Following 5 and 11-days of UV-B irradiation, L. minor showed decreased survival and growth, compared to control plants, but chlorophyll concentrations were not affected. Fiveday irradiated S. polyrhiza had lower daily growth rates compared to control plants, but survival and chlorophyll concentrations were not significantly influenced by UV-B exposure. The results of this study indicate that aquatic plant species respond differently to UV-B radiation, suggesting that community dynamics could be altered if the level of UV-B reaching the Earth’s surface increases.