Effects of Lead Stress on the Growth and Physiological Characteristics of Hedera nepalensis var. sinensis

purpose In order to investigate the effect of lead stress on the seedling growth characteristics of Hedera nepalensis var. sinensis, and the effects on growth and physiological characteristics were studied under lead stress to provide a theoretical base for lead resistant cultivation and the selection of lead-tolerant plants.

Method H. nepalensis var. sinensis were used as the experiment materials, the growth and physiological characteristics were determined under different concentrations of Pb(CH₃COO)₂ treatment groups.

Result The plant height, internodes’ spacing, stem biomass, leaf biomass and total biomass were significantly decreased under the lower Pb²⁺ concentration stresses (50, 200 μmol/L), and the MDA content, the soluble protein content, the antioxidant enzyme CAT and POD activities in plant leaves were also increased. While under the higher Pb²⁺ concentration stresses (400, 800 μmol/L), the plant height and the internodes’ spacing were significantly increased, but the biomass did not changed significantly, the stems appear to be significantly longer; at the same time, the soluble protein content, oxygen free radical content and antioxidant enzyme SOD activity also increased significantly.

Conclusion This study shows that H. nepalensis var. sinensis has strong tolerance to lead stress and could resist the damage of reactive oxygen under lead stress by activating its antioxidant system and increasing the soluble protein. In addition, the plants will be inhibited to growth by the lower concentration lead stress while be stimulated to excessive growth by the higher concentration lead stress.