植物膜脂过氧化作用和内源激素对UV-B辐射和稀土的响应

Responses of Membrane Lipid Peroxidation and Endogenous Hormones of Soybean Seedlings to UV-B Radiation and Rare Earth

[目的]为稀土农用拓展及环境污染防治提供策略。[方法]采用水培法研究了大豆幼苗(Glycinemax)膜脂过氧化作用和内源激素对UV-B辐射和稀土的响应。[结果]UV-B(T1-0.15W/m2和T2-0.45W/m2)辐射下,大豆幼苗叶绿素(Chl)和吲哚乙酸(IAA)含量在胁迫期(1～5d)逐渐下降,在恢复期(6～11d)上升;丙二醛(MDA)和脱落酸(ABA)含量先增(1～5d)后减(6～11d)。20mg/LLa(Ⅲ)减缓了上述指标在胁迫期的下降/上升趋势,加快了恢复期的上升/下降速度。[结论]La(Ⅲ)对大豆幼苗膜脂过氧化作用和内源激素的调控能提高叶绿素和IAA含量,改善活性氧的新陈代谢,抑制膜脂过氧化作用,减少ABA积累,且对低剂量紫外辐射(T1)的防护效果优于高剂量紫外辐射(T2)。

[Objective]The aim was to provide strategies for development of rare earth and control of environmental pollution.[Method]Re-sponses 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 （1-5 d） and then increased during the restoration phase （6-11 d） while contents of malonadialdehyde（MDA） and abscisic acid（ABA） gradually increased during the imposition of UV-B radiation （1-5 d） and subsequently decreased during recovery from UV-B stress （6-11 d） .With adding of La（Ⅲ） with the concentration of 20 mg/L,the de-cline/rise trend of chlorophyll,IAA,MDA and ABA contents was slowed down during the stress period while the rise/decline speed was accel-erated during the recovery period.[Conclusion]It suggests that the regulation of La（Ⅲ） on membrane lipid peroxidation and endogenous hor-mones could increase chlorophyll and IAA contents,improve the metabolism of reactive oxygen species （ROS） ,inhibit membrane lipid peroxi-dation,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.