【摘要】 为了揭示臭氧(O3)浓度升高对玉米活性氧(ROS)代谢及抗氧化酶活性的影响机理,以玉米(ZeamaysL.)为研究材料,利用开顶式气室(OTC)研究了臭氧浓度升高处理[(80±10)nmol·mol-1]下,玉米叶片活性氧产生速率、含量及抗氧化酶活性的变化。结果表明,与对照相比,高浓度臭氧处理下,抽雄期和灌浆期玉米叶片中超氧阴离子(O)产生速率显著增加(P<0.05),过氧化氢(H2O2)含量极显著增加(P<0.01)。处理至灌浆期时,丙二醛(MDA)含量增加了22.6%,显著高于对照(P<0.05),而相对电导率在抽雄期和灌浆期均极显著高于对照(P<0.01),与对照相比,分别增加了20.0%和26.3%,表明细胞膜受损严重。在各个生育时期内,臭氧处理玉米叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性均低于对照,表明臭氧浓度升高能够抑制玉米叶片抗氧化酶的活性。本试验中抗氧化酶活性在整个处理期间呈现出逐渐升高的趋势,说明玉米植株对O3胁迫具有保护性机制,在一定程度上缓解臭氧对其造成的伤害。!2更多还原

【Abstract】 With the use of coal and petroleum, O3 concentration gradually increased. Terrestrial plant was damaged by high concentration O3 of near-surface. In order to reveal effect mechanism of elevated ozone( O3) concentration on maize( Zea mays L.) reactive oxygen species ( ROS) metabolism and antioxidative enzymes activities, open top chambers (OTCs) were utilized to investigate change of reactive oxygen species production rate, content and antioxidative enzymes activities in maize leaves under elevated ozone concentration treatment ( 80± 10nmol·mol-1) . The results indicated that superoxide anion( O ) production rate increased significantly( P<0.05) and hydrogen peroxide ( H2O2) content increased highly significant ( P<0.01) under elevated ozone concentration treatment compared with the control in tasseling stage and filling stage. In filling stage, malondialdehyde( MDA) content increased 22.6% significantly( P<0.05) . Relative electrical con- ductivity presented highly significant difference( P<0.01) compared with the control, raised respectively 20.0% and 26.3% in tasseling stage and filling stage, which showed that cell membrane was destroyed severely. In every growing stage, activities of superoxide dismutase( SOD) , catalase( CAT) and peroxidase( POD) in maize leaves under elevated ozone concentration treatment were lower than the control, which showed that antioxidative enzymes activities were restrained in maize leaves under elevated ozone concentration treatment. Antioxidative enzymes activities presented gradually increasing trend during the whole treatment period, which showed that maize had protective mechanism to ozone stress and this damage ofozone stress was relieved in some extent.更多还原