Impact of UV-B radiation on photosynthesis - an overview.

Ultraviolet-B (UV-B) radiation constitutes a minor part of the solar spectrum, being most of this solar radiation absorbed by the UV-screening stratospheric ozone layer. Yet, a global depletion of the ozone layer, largely due to the release of chlorofluorocarbons caused by human activities, has resulted in an increase of solar UV-B radiation at the earth's surface. Accordingly, in the temperate latitudes, such ozone decrease reached ca. 3% and 6% in the North and South hemispheres, respectively, between 2002 and 2005 (as compared to the 1970s). Despite the uncertainty of long-term predictions, it is also estimated an UV-B increase of 5-10% over temperate latitudes within the next 15 years In this context, this work aim at to present an overview of plants sensitivity/tolerance to UV-B irradiation mostly considering the key photosynthetic metabolism. [ABSTRACT FROM AUTHOR]