凤仙花生物量及抗氧化酶系统对重金属铅胁迫的生理响应

Study on the Physiological Response of the Biomass and Antioxidant Enzyme System of Impatiens balsamina L.to Heavy Metal Pb Stress

[目的]探讨凤仙花在铅胁迫下生物量及其抗氧化酶系统的变化。[方法]采用盆栽试验,对凤仙花在不同浓度Pb(250、5007、50、1 0001、500 mg/kg)胁迫下的生物量及不同时期抗氧化酶系统的变化进行了研究。[结果]随着Pb离子浓度的增高,凤仙花的生物量先升高后下降,1 500 mg/kg处理组中凤仙花茎叶生物量由对照的2.21 g下降到2.07 g,是对照的93.67%;根的生物量由对照的0.54 g下降到0.45 g,是对照的83.33%。3种抗氧化酶表现出同样的变化趋势,低浓度的Pb促进其含量增加,高浓度的Pb使其含量逐渐下降,SOD和POD含量的下降程度和持续时间与铅胁迫程度有关,而铅胁迫时间对CAT的活性没有明显影响。[结论]高浓度的Pb对凤仙花的生长发育产生了严重伤害。

[Objective] Tne research aimed to discuss the biomass of Impatiens balsamina L. and the changes of its antioxidant enzyme system under Pb stress. [Method] In pet experiment, the biomass of I. balsamina under Pb stress with different concentrations of 250, 500,750,1 000 and 1 500 mg/kg and the changes of antioxidant enzyme system in different periods were studied. [Result] With the concentration increasing of Pb ion, the biomass of I. balsamina was first increased and then decreased. Tne biomass of stem and leaf in I. balsamina in the treatment of 1 500 mg/kg was decreased from 2.21 g （CK） to 2.07 g, which was 93.67 % of CK. Tne root biomass was decreased from 0.54 g （CK） to 0.45 g, which was 83.33 % of CK. Tnree kinds of antioxidant enzymes showed the same change trend. Pb at low concn.promoted the increase of their content, while Pb at high concn, made their content gradually decreased. Tne decreasing degree and duration of SOD content and POD content were related with the degree of Pb stress. But the time under Pb stress had no obvious effect on CAT activity. [Conclusion] High concn, of Pb caused serious damages to the growth and development of I. balsamina.