Increased UV-B Radiation Affects the Viability, Reactive Oxygen Species Accumulation and Antioxidant Enzyme Activities in Maize (Zea mays L.) Pollen

摘要

The increase in UV-B radiation reaching the earth's surface has prompted extensive studies on the effects of UV-B on plants. However, most of these studies have not addressed the close characteristics related to future survival of plant populations. The purpose of this study was to investigate the effeets of UV-B radiation on reactive oxygen species (ROS) accumulation and antioxidant defense system in relation to germination, tube length and viability of maize pollen. Our results indicate that increased UV-B radiation decreased the pollen germination rate and tube length in vitro and also its fertilization ability in the field. Production of O^sub 2^^sup .-^ and H^sub 2^O^sub 2^ increased by UV-B radiation treatment, and their continuous accumulation resulted in lipid peroxidization. The activities of superoxide dismutase, catatase, peroxidase and DPPH-radical scavenging were decreased by increased UV-B radiation. The increased ROS and lipid peroxidization, and decreased activities of the antioxidants may be attributed to the effects of UV-B radiation on pollen germination, tube growth and fertilization ability. [PUBLICATION ABSTRACT]