为探明PP333对马铃薯试管苗壮苗及离体保存延缓衰老的作用机理。本试验以马铃薯试管苗为材料，在MS培养基中添加不同浓度PP333，测定其生长过程中CAT、POD、SOD等抗氧化酶活性及MDA和可溶性蛋白含量的动态生理指标。结果显示：0.01、0.05及0.25 mg/L PP333处理，诱导了CAT、POD、SOD等抗氧化酶活性的上升，保持了膜脂过氧化产物MDA相对较低的含量水平，并延缓了可溶性蛋白的下降。而1.25 mg/L PP333处理，虽有较高的CAT、POD活性，但SOD活性低，可溶性蛋白明显下降。由此可知，低浓度（0.01~0.25 mg/L）PP333可保持较高的抗氧化酶和蛋白质水平以及较低含量的MDA，从而培育壮苗和延缓试管苗的衰老。较高浓度（1.25 mg/L）PP333则使蛋白质含量和SOD活性降低，表现出一定的毒害作用。

To study the action mechanism of PP333 on nurturing in vitro preserved strong seedling of potato test-tube plantlets and on delaying its aging, potato test-tube plantlets were used as explants, different concentrations of PP333 were added into MS culture media to determine the activity of antioxidase (CAT, POD, SOD etc.) and the dynamic physiological indices of MDA and soluble protein content. The results showed that samples treated with 0.01, 0.05 and 0.25 mg/L PP333 had an increased antioxidase (CAT, POD, SOD etc.) activity, kept a relatively low content level of MDA and their decreasing of soluble protein content was delayed. The samples treated with 1.25 mg/L PP333 had a low SOD activity and their soluble protein content was decreased significantly, though they kept a relatively high CAT and POD activities. In conclusion, low concentration of PP333 can help nurturing strong seedlings and delaying the aging of test-tube plantlets by keeping a low MDA concentration and a high antioxidase and protein level while high concentration (1.25 mg/L) of PP333 showed detrimental effects by lowering the content of protein and the activity of SOD.