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.