紫薇对SO_2胁迫的生理反应

采用简易静态熏气装置对2 a生盆栽紫徽(Lagerstroemia indica)进行熏气处理,研究了不同质量浓度SO_2对紫薇叶片细胞膜适性、抗氧化酶活性、丙二醛含量、脯氨酸、可溶性蛋白质及叶绿素含量的影响.结果表明,0～19.00 mg·m~(-3)熏气15 d后,随SO_2质量浓度增加,紫薇叶片膜透性增大,丙二醛、脯氨酸含量增加,可溶性蛋白质含量先上升后下降,叶绿素a、叶绿素b和总叶绿素含量比对照显著降低.随SO_2质量浓度增加,紫薇叶片SOD,POD,CAT活性均呈上升趋势.SOD和CAT活性增长具有相似性,在0～14.25 mg·m~(-3)处理期间,酶活性增长缓慢,在19 mg·m~(-3)处理下酶活性迅速增大,SOD和CAT活性分别比对照增加了44.9%和74.37%.POD活性增长趋势与SOD和CAT有所不同,在0～14.25 mg·m-3处理期间增长较快,比对照增加了46.04%,在19mg·m~(-3)处理下,几乎不再增长.3种抗氧化酶活性的增长对清除体内O_2~(-·)及H_2O_2起到重要作用,减轻了膜脂过氧化程度,提高了紫薇对SO_2的抗性.

Physiological responses of Lagerstroemia indica to sulfur dioxide stress

In this study, two-year-old potted samples of Lagerstroemia indica were treated with different concentrations of sulfur dioxide gas in a closed fumigation equipment, the changes in activities of SOD, POD and CAT, membrane permeability, and contents of MDA, proline, soluble proteins, chlorophyll of them were measured. The results showed that after the materials were exposed to sulfur dioxide gas at concentrations of 0～19. 00 mg·m~(-3) for 15 days, the membrane permeability, the contents of MDA and the proline of them increased, while soluble protein content increased and then decreased and the contents of chlorophyll - a, chlorophyll - b and total chlorophyll decreased with the increment of sulfur dioxide concentration compared with the control level. With the increase of SO_2 concentration, the SOD , POD, CAT activity of the samples all showed an upward trend. The increase of SOD activity and CAT that of activity are similar. The enzyme activity increased slowly when the samples were treated with the SO_2 concentration between 0～14. 25 mg·m~(-3) , while it increased rapidly at the concentration of 19 mg·m~(-3). meanwhile, the SOD and CAT activity increased by 44. 9% and 74. 37% compared with the control. The POD activity growth trends are different from that of SOD and CAT, which increased by 46. 04% under the concentration of 0～14. 25 mg·m~(-3) compared with the control, but it hardly increased at the concentration of 19 mg·m~(-3) . The results indicated that the increasing of the three antioxidant enzymes could improve the resistance of L indica to SO_2 and plays an important rolein clearing the O_2~(-·) and H_2O_2,and reducing the degree of membrane lipid peroxidation.