不同浓度Na2SO3处理对吊兰和天竺葵活性氧代谢及保护酶活性的影响

通过对吊兰和天竺葵进行不同浓度(1 5005、000和7 000 mg/L)Na2SO3溶液浸泡处理模拟大气SO2污染胁迫,比较处理2、4、68、h后吊兰和天竺葵叶片的超氧自由基(O2.-)产生速率、过氧化氢(H2O2)含量、丙二醛(MDA)含量及超氧化物岐化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性的动态变化过程,结果发现,随Na2SO3溶液浓度的升高,吊兰和天竺葵叶片中O2.-、H2O2的含量呈逐渐上升的变化趋势,但吊兰的增幅小于天竺葵。各处理浓度下2种植物SODP、OD活性均高于对照,但SOD随处理时间延长而降低,而POD活性在处理2~6 h上升,6~8 h下降。CAT活性只有在1 500 mg/L Na2SO3处理下高于或接近对照,各处理CAT活性随处理时间延长逐渐下降。吊兰叶片中这三种酶活性高于天竺葵。研究还表明,高浓度Na2SO3处理后期吊兰和天竺葵叶片内活性氧清除酶类活性下降,不能及时清除体内大量的活性氧,从而引起MDA的大量积累,引起膜损伤。

Effect of Na2SO3 on Metabolism of Reactive Oxygen and Protective Ezyme Activity in Leaf of Chlorophytum comosum jacq and Pelargonlum hortorum

Under the different concentrations(1?500?mg/L,5?000?mg/L and 7?000?mg/L) of Na_2SO_3 stress,the super anion content(O_2~(.-)),H_2O_2 and malondialdehyde(MDA) content and activity of cell defense enzymes in leaf of Chlorophytum comosum and pelargonium hortorum were measured in different treatment times(2?h,4?h,6?h and 8?h).The result showed the O_2~(.-)and H_2O_2 content was increased with the increment of Na_2SO_3 concentration,meanwhile,the Na_2SO_3 stress led to the increase of surperoxide dismutase activity(SOD) compared with the control,but decreased with the elongation of treatment time,the peroxidase(POD) activity was increased from 2?h to 6?h after the treatment of different concentrations,and decreased from 6?h to 8?h.The calatase(CAT)activity was decreased after Na_2SO_3 was treated with 5?000?mg/L and 7?000?mg/L concentration and was increased from 2?h to 6?h then decreased from 6?h to 8?h after Na_2SO_3 was treated with 1?500?mg/L concentration.It proved that the treatment of low Na_2SO_3 concentration had light effect,but under the high concentration treatment,the system of scavenging reactive oxygen species(ROS) couldn't scavenge the ROS in time,which caused the accumulation of ROS and the damage of membrane,and in turn caused the accumulation of MDA.