Effect of Rare Earths on Plants under Supplementary Ultraviolet-B Radiation： Ⅱ. Effect of Cerium on Antioxidant Defense System in Rape Seedlings under Supplementary Ultraviolet-B Radiation

• Published in: Journal of rare earths 2006-06, Vol.24 (3), p.364-368
• Main Author: 梁婵娟 黄晓华 陶文沂 周青
• Format: Article
• Language: English
• Subjects: 0614.3; cerium; elevated UV-B radiation; membrane permeability; protective enzymes; rape seedlings; rare earths; 保护酶; 膜透性
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(06)60125-7

Effects of cerium （Ce^3＋ ） on membranous protective enzymes in rape seedlings exposed to two levels of enhanced uhraviolet-B radiation （UV-B, 280 - 320 nm） were studied by hydroponics in the laboratory. The results show that the chlorophyll content decreases and membrane permeability increases in the leaves under UV-B irradiation with an intensity of 0.15 and 0.35 W·m^-2. The activities of SOD, CAT and POD are first increased and then decreased in leaves exposed to a low level of UV-B radiation. POD activity in leaves exposed to a high level of UV-B radiation is enhanced constantly. The sensitivities of these enzymes to UV-B radiation are SOD 〉 CAT 〉 POD. The injury by UV-B radiation on the functions of protective enzymes is lightened, their ability to scavenge radicals is improved, and the membrane permeability is maintained by Ce. Furthermore, the protective effect of cerium is more obvious in plants exposed to low levels of UV-B radiation than to high levels of it. Accordingly, all results prove that the protective effect of Ce on plants under UV-B radiation is realized through the protective system of plants.