Ultraviolet-B (UV-B) Radiation Effects on Plants

摘要

The visible spectrum of light (400-700 nm) provides energy for photosynthesis and also information for plant growth and development through photoreceptor molecules (Briggs et al., 2001; Jordan et al., 1986; Nagy and Schafer, 2002; Short and Briggs’ 1994). At shorter wavelengths than the visible spectra is the ultraviolet (UV) region. This region is divided into three wavebands: UV-A (320-380 nm), UV-B (280-320 nm) and UV-C (< 280 nm). The passage of UV-A radiation is not restricted by stratosphericozone and therefore passes through to the earth's surface. UV-C is lethal to biological systems and completely removed by the ozone layer. UV-B radiation, however, is removed to some extent by the ozone layer, but recent depletion in stratospheric ozoneis allowing an increase in UV-B to impact on the biosphere. It is the increase in UV-B that is of concern to agriculture, horticulture, and ecosystems. This increase in UV-B has the potential to damage plants, change the development, and alter the chemical composition of plant tissue. In consequence, plant propagation under controlled environments must also take into consideration the quality of light including UV-B. For comprehensive reviews of UV-B effects on plants refer to Jordan, 1996; Jordan, 2002; and Campbell et al., 1999.