铜胁迫对穿心莲幼苗生长及生理特性的影响

通过对盆栽穿心莲(Andrographis paniculata)幼苗浇灌Cu SO4溶液实验,研究外施Cu2+对穿心莲幼苗的生理特性和药效成分含量的影响。结果显示,外施Cu2+对穿心莲幼苗的生长、生理生化指标和穿心莲内酯、脱水穿心莲内酯的含量均有显著影响。当Cu SO4溶液浓度超过6.25 mmol/L时,Cu2+能显著抑制穿心莲幼苗株高、叶长、叶宽的增长,且随胁迫时间的延长和Cu2+浓度的增大抑制作用增强;穿心莲叶片中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量均随Cu2+浓度增大和胁迫时间的延长而升高,当Cu SO4溶液浓度达到12.5 mmol/L且胁迫20 d和30 d时,叶片中SOD活性达到对照组的168.3%和171.18%;过氧化物酶(POD)、过氧化氢酶(CAT)活性则随Cu2+浓度的增大呈先升高后下降的趋势;当外施Cu SO4溶液浓度大于1.25 mmol/L时,与对照相比,穿心莲药效成分穿心莲内酯和脱水穿心莲内酯的含量均显著降低(P0.05)。研究结果表明,外施Cu SO4溶液浓度高于6.25 mmol/L时,能显著影响穿心莲幼苗的生理特性和有效成分含量,从而降低穿心莲药材的产量和质量。

Coppex Stress Effects on the Growth and Physiological Characteristics of Andrographis paniculata Seedlings

The effects of exogenous copper ion stress on seedling growth, physiological properties and efficacy component contents in Andrographis paniculata were investigated using a pot experiment. Results showed obvious effects of exogenous copper ion stress on seedling growth, physiological and biochemical indexes, and contents of andrographolide and dehydroandrographolide in A. paniculata. Seedling growth was markedly inhibited as the concentration of copper-bath increased to more than 6.25 mmol/L, and the inhibiting effect became stronger with both increasing stress time and copper ion concentration. Both SOD activity and MDA content increased with stress time and copper ion concentration. The SOD activity reached 168.3% and 171.18% in the control group, respectively, when the concentration of the copper-bath reached 12.5 mmol/L and stress time was 20 and 30 days, but the activities of POD and CAT showed increasing trends at first, followed by decreasing trends. Compared with the control, the medicinal compositions of andrographolide and dehydroandrographolide decreased significantly (P<0.05) at a exogenous copper-bath concentration of 1.25 mmol/L. Our results demonstrated that when the exogenous copper-bath concentration was greater than 6.25 mmol/L, there was an observable effect on the physiological properties and the effective constituent contents in A. paniculata, resulting in a reduction in both production and quality.