外源硼酸对铀胁迫下四季豆生理以及铀富集的影响

为了研究外源硼酸对铀胁迫下四季豆生理生化以及铀富集能力的影响,笔者以四季豆(Phaseolus vulgaris L.)为材料,通过盆栽控制试验,在含有铀污染的土壤中分别施加0、10、20、30、40、50 mg/kg的硼酸,在温室中种植培养四季豆,待四季豆开花前取样测定其生理指标和铀富集含量。结果表明:(1)随着硼酸浓度的升高,最大光化学效率(FV/Fm)和光合性能指数PIABS以及单位反应中心吸收的光能(ABS/RC)、单位反应中心捕获的能力(TRo/RC)、单位反应中心捕获的用于电子传递的能量(ETo/RC)和单位反应中心耗散的能量(DIo/RC)均呈现先升高后下降的趋势;叶绿素、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性、可溶性蛋白、可溶性糖、游离脯氨酸也呈现先上升后下降的趋势;丙二醛(MDA)呈现先下降后升高的趋势;(2)随着外源硼酸浓度的升高,四季豆地上部和地下部铀含量以及植物铀含量都升高。说明了外源施加适宜浓度的硼酸可以提高四季豆对重金属铀的抗性,增加四季豆对铀的富集能力和转移能力。

The Influence of Boric Acid on Physiology and Uranium Accumulation in Phaseolus vulgaris L. under Uranium Stress

The aim is to study the effect of exogenous boric acid on physiological and biochemical indicators of Phaseolus vulgaris L. and uranium enriched capability under uranium stress. We used Phaseolus vulgaris L. as material, carried out the pot controlled experiments by applying 0, 10, 20, 30, 40, 50 mg/kg boric acid in the uranium contaminated soil. Phaseolus vulgaris L. was planted in the greenhouse, and was sampled before flowering, and the physiological indicators and uranium enrichment content were measured. The results showed that: as the boric acid concentration increased, the maximum photochemical efficiency (Fv/Fm), performance index (PIABS), the energy absorption per active reaction center (ABS/RC), the capture capability per active reaction center (TRo/RC), the capture energy used for electron transfer peractive reaction center (ETo/RC) and the non-photochemical energy dissipation per active reaction center (DIo/RC) showed a downward trend after a rise first. Chlorophyll, superoxide dismutase (SOD), peroxidase (POD) activity, soluble protein, soluble sugar, free proline also rose firstly, then declined; Malondialdehyde (MDA) firstly decreased then increased. With exogenous boric acid concentration increased, the uranium in above- ground and under- ground part of Phaseolus vulgaris L. were increased, indicating that appropriate concentration of exogenous boric acid could increase resistance to heavy metals and uranium, as well as the enrichment capacity and the ability to transferin Phaseolus vulgaris L..