水杨酸对大丽花多酚氧化酶的影响

目的探讨如何提高大丽花的抗病性．方法以大丽花为实验材料，使用水杨酸（SA）叶面喷施处理方式，分析在水杨酸处理其植株叶片后，随时间变化，不同浓度的水杨酸对PPO活性的影响，为研究大丽花的抗病性提供实验依据．结果本品种大丽花的PPO最适pH为5．8；SA对大丽花PPO有一定的影响．用低于0．5mmol／L的SA处理后的大丽花，PPO活性无显著影响；1～2mmol／L的SA对PPO活性起促进作用，并且于24h达到高峰；而3mmol／L的SA对PPO活性起明显的抑制作用．而用以上几组浓度的SA处理大丽花后，PPO活性在48～60h之后逐渐恢复到未处理状态．结论外源SA对大丽花进行处理后对PPO活性在一定时间内有诱导作用．

Effects of Salicylic Acid on Polyphenol Oxidase in Dahlia pinnata

Objective To explore how to improve the disease resistance of Dahlia pinnata. Method The salicylic acid （SA） was sprayed on the Dahlia pinnata and then,the effect of SA on Poly Phenol Oxidase （PPO） activity with the change of the time and at different concentrations of SA was analyzed to provide an experimental evidence for the study on the disease resistance of Dahlia pinnata. Results The optimum pH value for this variety of Dahlia pinnata was 5.8, SA had certain effect on PPO activity, SA less than 0.05 mmol/L had no significant effect on PPO activity, PPO activity could be promoted by 1 - 2 mmol/L SA and the PPO activity could reach a peak value after 24 hours ,while 3mmol/L SA exerted significant inhibitory effect on PPO activity. After being treated respectively with above concentrations of SA, PPO activity restored gradually to the level before the treatment after 48 - 60 h. Conclusion After the treatment of Dahlia pinnata with exogenous SA, PPO activity in Dahlia pinnata could be induced within a certain range of time.