锌对水花生生长及活性氧代谢的影响

采用Hoagland营养液加不同浓度梯度的锌培养水花生植株，研究了锌对水花生的生长特性和部分生理指标的影响。研究表明，低浓度锌(10mg•L-1)，水花生植株外伤症状为轻度伤害；当锌浓度＜50mg•L-1时，植物细胞内的SOD、POD、CAT酶活性均有所升高。而随着锌浓度增加，可造成植株生长缓慢、生物量下降；叶片色素下降；水花生体内活性氧清除系统中SOD、POD、CAT三种酶平衡被破坏，不能有效阻止O2•-和H2O2的积累，细胞膜透性增大、MDA含量高度积累，从而影响植物的正常生长代谢，使之出现毒害症状。

Effects of Zn on the growth and scavenging system of activated oxygen of Alternanthera philoxeroides

The physiological and biochemical indexes of Alternanthera philoxeroides were investigated with different contents of Zn in Hoagland cultivation. When the pollution caused by Zn at the low concentration of Zn (10mg•L-1)，the plant external injury of Alternanthera philoxeroides was not significant. At the concentrations of Zn (＜50mg•L-1)，the protection enzyme in cells such as SOD，POD and CAT increased. But with the Zn level increasing, the plants grew slowly, the biomass decreased, and the chlorophylls level decreased. Meanwhile the balance of these kinds of enzymes was destroyed in the active oxygen scavenging system。The accumulation of O2•- and H2O2 cannot be prevented effectively, the cell membrane permeability increased, the MDA content accumulated highly. Thus the growth of plant was affected, and toxic symptoms appeared.