EFFECT OF ZN ON PROTECTIVE ENZYM ES ACTIVITY,OSMOLYTES CONTENT AND CA2+ D ISTRIBUTION IN LEAVES OF NYM PHO IDES PELTATUM

作者：Qin-Song XU, Guo-Xin SHI, Wang-Dong JI, Kaihe Du, Ye XU · 发表于：Acta Hydrobiologica Sinica · 年份：2009 · DOI：10.3724/issn1000-3207-2009-4-613-7 · 研究领域：Plant Micronutrient Interactions and Effects

Zinc (Zn) is an essentialmicroelement for normal growth and development of plants at low concentration; how2ever, it is also an important environmental pollutant due to anthropogenic pressure as well. In the present study, Nymphoides peltatum, a rooted2floating aquatic macrophyte, was cultivated with elevated concentration of Zn (0, 5, 10, 15 and 20mg/L) for 9d respectively. The response of activities of superoxide dismutase(SOD) and peroxidase(POD), osmolytes(proline and soluble sugar) to Zn stress was investigated and Ca2+ ultrastructural distribution in leaf cells was examined with the cytochemicalmethod of calcium antimonate precipitation. The results indicated that Zn decreased SOD activity by 11. 46% -75. 22% and the inhibition action reached significant level (R = -0. 8642, p 2+ mainly distributed within intercellular space and vacuole, some calcium deposits could be randomly found in cytoplasmic matrix and nucleus under normal conditions, when different dose of Zn was added into the culture solution, and the calcium level in these compartments lowered while that in cytoplasm increased remarkably, especially bigger particles of calcium deposits appeared at the inner aspect of plasmalemma and cell nucleus, which might be attributed to the opening of the calcium channels in plasmalemma and tonoplast and the loss of activity of the Ca2+ pump, this, in turn further enhanced the calcium level of cell interior. The rise of Ca2+ level in cytoplasm and cell nucleusmaybe relate...