Effects of ultraviolet radiation on plant cells

Recent measurements of ozone levels have led to concern that the stratosphe ric ozone layer is being depleted as a result of contamination with man-mad e chlorofluorocarbons. Concomitantly, the amounts of solar UV-B radiation r eaching the Earth's surface is increasing. UV-B radiation has been shown to be harmful to living organisms, damaging DNA, proteins, lipids and membran es. Plants, which use sunlight for photosynthesis and are unable to avoid e xposure to enhanced levels of UV-B radiation, are at risk. Thus, mechanisms by which plants may protect themselves from UV radiation are of particular interest. This review will summarizes the main aspects of ultraviolet radi ation on plants at physiological and biochemical level, with particular emp hasis on protective structures and mechanisms. (C) 2001 Elsevier Science Lt d. All rights reserved.