Changes in antioxidant and pigment pool dimensions in UV-B irradiated maize seedlings

Ultraviolet-B (UV-B) radiation (280-320 nm) is an environmental challenge affecting a number of metabolic functions through the generation of reactive oxygen species (ROS). Plants protect themselves from this harmful radiation by synthesizing flavonoids, which act as a screen inside the epidermal cell layer, and by making adjustments to the antioxidant systems at both cell and whole organism level. This study describes the flavonoid content, the photosynthetic pigment composition and the proline, tocopherol. and ascorbate content in UV-B exposed maize plants. Following exposure, the tocopherol content was slightly, but significantly lower, pointing to the membrane environment as a primary target for UV-B radiation. The water-soluble antioxidant content was largely unaffected, but an enhanced turnover in the ascorbate-glutathione cycle might be needed for tocopherol regeneration. (C) 2003 Elsevier Science B.V. All rights reserved.