二氧化硫暴露对拟南芥叶片形态和生理生化指标的影响

Effects of Sulfur Dioxide on the Morphological and Physiological Biochemical Parameters in Arabidopsis Thaliana Plants

采用室内培养及密闭箱静态熏气方法,研究了不同浓度SO2暴露对拟南芥(Arabidopsis thaliana)叶片形态和生理生化指标的影响。结果显示,拟南芥暴露于SO214d后,叶面气孔开度变小。浓度10mg·m-3组促进植株生长发育,SOD和CAT活性无明显改变,30mg·m-3SO2组3种酶活性呈诱导性增高,其中POD增幅最大,SO2浓度90mg·m-3时,CAT活性被抑制,丙二醛(MDA)含量增加,株高、叶片数和叶片面积显著降低,可溶性蛋白含量减少,叶片出现明显可见伤害。研究结果表明,在低浓度条件下,拟南芥能够通过调节气孔开放、细胞抗氧化酶活性等使植株适应SO2胁迫,但是高浓度SO2暴露会引起细胞氧化损伤,影响植物生长发育。

Effects of SO2 exposure on the morphological and physiological biochemical parameters were investigated in model plant A rabidopsis thaliana. Test plants were exposed to SO2 at concentrations of 10, 30 and 90 mg·m^-3, respectively, 4 h per day for 14 d in an environment-controlled chamber, and then some parameters were measured by detecting the stomatal aperture, activities of antioxidant enzymes and growth rate. The results showed that stomatal aperture and the ratio of stomatal opening area decreased with an increase of the amount of closed stomata when plants exposed to SO2. The activities of catalase （CAT）, superoxide dismutase （SOD） and peroxidase （POD） increased dose-de-pendently in Arabidopsis thaliana plants. 10 mg·m^-3 SO2 exposure had no markedly effect on the activities of SOD and CAT, and showed a positive effect on plants growth and development. 30 mg·m^-3 SO2 exposure significantly enhanced the activities of the three antioxidant enzymes, and POD activity had the maximum increment. Exposure to 90 mg·m^-3 SO2 caused decreases in the activity of CAT and the content of soluble proteins, and inhibition of plant growth and development, but an increase in the content of malondialdehyde （MDA）. Our results suggested that A rabidopsis thaliana can adapt to SO2stress by controlling stomatal opening and activities of antioxidant enzymes, however, exposure to higher concentration can cause oxidative damage to plants.