铅胁迫对咖啡幼苗叶绿素含量及抗氧化酶活性的影响

Effects of Lead Stress on Chlorophyll Content and Antioxidant Enzyme Activity in Coffee Seedlings

为咖啡的抗重金属胁迫机制研究提供理论依据,采用水培方法,在不同浓度梯度铅胁迫下研究咖啡幼苗超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、丙二醛(MDA)以及叶绿素含量的变化。结果表明:铅浓度较低时,咖啡幼苗叶绿素含量略有增加,但随着铅浓度升高,叶绿素含量呈下降趋势;CAT、POD活性呈先升高后下降趋势,而SOD活性随着铅浓度的增加逐渐下降,MDA含量则一直呈现增加趋势,说明咖啡幼苗膜系统受到了一定程度的破坏。

To provide a theoretical reference for investigating the resistance mechanism to heavy metal of coffee seedling,water culture method was used to study the transformation of chlorophyll,SOD,POD, CAT and MDA with different concentrations of lead.The results showed that the contents of chlorophyll slightly increased under low lead concentrations,but decreased when lead concentrations further increased. The activities of CAT and POD went up at the beginning of lead stress,but they were decreased as the quantity of lead increasing.The activities of SOD showed the downtrend as the quantity of lead increasing, while the MDA content increased all the time,which suggested that the membrane system of coffee seedling was damaged by lead stress.