Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth

[Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth were studied through hydroponics in laboratory. [Result] The results showed that under irradiation of UV-B(T1-0.15 W/m2 and T2-0.45 W/m2), chlorophyll and indole-3-acetic acid(IAA) contents firstly decreased during the stress phase (1-5d) and then increased during the restoration phase (6-9d) while contents of malonadialdehyde(MDA) and abscisic acid(ABA) gradually increased during the imposition of UV-B radiation (1-5d) and subsequently decreased during recovery from UV-B stress (6-9d) . With adding of La (Ⅲ) with the concentration of 20mg•L-1, the decline/rise trend of chlorophyll, IAA, MDA and ABA contents was slowed down during the stress period while the rise/decline speed was accelerated during the recovery period. [Conclusion] It suggests that the regulation of La (Ⅲ) on membrane lipid peroxidation and endogenous hormones could increase chlorophyll and IAA contents, improve the metabolism of reactive oxygen species (ROS), inhibit membrane lipid peroxidation, decrease the accumulation amount of ABA and alleviate injury of UV-B radiation to soybean seedlings. Further, the protective potential of La (Ⅲ) was better under low UV-B radiation than under high one