Modeling the effect of ultraviolet radiation on the photosynthetic potential of Prochlorococcus and Synechococcus cyanobacteria

摘要

We used mathematical models of photosynthesis to quantify the effects of ultraviolet (UV) radiation on the photosynthetic potential of Prochlorococcus and Synechococcus marine cyanobacteria living at 0 degrees and 40 degrees N/S latitude. We show that UV is an environmental stressor for these organisms near the ocean surface, accounting for roughly two-thirds of the potential photo synthetic inhibition. Prochlorococcus showed a higher inhibition and integrated photo synthetic potential throughout the water column than Synechococcus, since the former is more vulnerable to UV damage at the surface and more successful at greater depths compared to the latter. The maximum photosynthetic activity was reached beneath the photoactive zone, largely due to the harmful effects of UVA. UV inhibition varies with latitude, due to variability in repair capacity for Synechococcus, and the existence of more diverse mechanisms of acclimation to irradiance and temperature for Prochlorococcus. The lowest photoinhibition is estimated to occur at 0 degrees latitude, since the interactive effects of high temperature and irradiance have a positive effect on photo acclimation to UV damage.