中文摘要：

为进一步研究甜菜碱对重金属铅胁迫下玉米幼苗生长发育的影响，本实验用甜菜碱处理不同浓度重金属铅溶液胁迫下的玉米幼苗，观测玉米幼苗的生长状况，对玉米幼苗过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)以及丙二醛(MDA)含量等生理指标进行测定，探讨外源甜菜碱对玉米幼苗重金属铅胁迫的影响。结果显示，甜菜碱处理后，玉米幼苗体内POD，SOD，CAT活性都明显提高，而MDA含量的增加量明显降低，表明甜菜碱在一定程度上可缓解重金属铅对玉米幼苗的胁迫。

英文摘要：

In order to study the effects of betaine on the growth and development of maize seedlings under heavy metal Pb stress,maize seedlings were treated with betaine under different concentrations of Pb stress.The growth of maize seedlings was observed and the activities of peroxidase(POD),superoxide dismutase(SOD),catalase(CAT)and malondialdehyde(MDA)content were measured,to investigate the effects of exogenous betaine on Pb stress of maize seedlings.The results showed that the activities of POD,SOD and CAT in maize seedling were significantly increased after betaine treatment,and the increase of MDA content was significantly decreased,indicating that betaine could relieve the stress of maize seedlings to a certain extent.