三种诱抗剂处理对苎麻叶片 PPO 和 POD活力的影响

多酚氧化酶（PPO）及过氧化物酶（POD）对植物抗性起重要作用，可被诱抗剂诱导产生。因此，本研究应用三种诱抗剂（水杨酸SA、壳寡糖CO、茉莉酸甲酯MeJA ）及其不同浓度喷施“川苎8号”苎麻幼苗，测定喷施后不同时间其叶片内PPO及POD活性，根据酶活性升高程度来筛选能使苎麻产生较大抗性的合适诱抗剂及使用浓度。结果表明喷施上述三种诱抗剂均能使叶片内PPO及POD活性升高；0.8 mM SA、3 g/L CO和1 mM MeJA喷施均比同类诱抗剂的其他浓度酶活性要高；同时，三种诱抗剂相比，0.8mM SA喷后7-8d， PPO和POD酶活性均达到最大，效果较其他2种诱抗剂稳定。由此认为SA为诱导苎麻产生抗性的合适诱抗剂，0.8 mM浓度提前7 d喷施能达到较好效果。

Effects of Three Elicitors on PPO and POD Activities in Ramie Leaves

Polyphenoloxidase （ PPO） and peroxidase （ POD） are important for plant resistance and can be induced by elicitors.In this paper , three elicitors （ Salicylic Acid, Chitosan oligosaccharide and Methy jasmonate ） with different concentrations were sprayed on the seedlings of ramie ″Chuanzhu No.8″, and then PPO and POD activities at different time were monitored.The elicitor with a certain concentra-tion which could stimulate the highest increase of enzyme activities was regarded as the suitable one.The results showed that these three elicitors could all raise enzyme activities of PPO and POD.Especially 0.8mM Salicylic Acid, 3g/L Chitosan oligosaccharide and 1mM Methy jasmonate could induce higher enzyme activities than other concentrations of the same elicitors.Additionally , the peak of both the en-zyme activities appeared around 7-8 d after spraying 0.8 mM Salicylic Acid , and the effects were more stable than the other two elicitors.Therefore , Salicylic Acid was selected as a better elicitor for inducing ramie resistance , 0.8 mM of concentration and spraying 7 d early could get a good result.