【摘要】 为了揭示CO2和O3浓度升高及其复合作用对植物活性氧(ROS)代谢及抗氧化酶活性的影响机理,以玉米(Zea maysL.)为研究材料,利用开顶式气室(OTCs)研究了CO2和O3浓度升高及其复合作用下,玉米叶片活性氧产生速率、含量,膜脂过氧化程度,抗氧化酶活性,净光合速率及玉米籽粒产量的变化。结果表明,在整个生育期内,与对照相比,高浓度CO2((550±20)μmo.lmol-1)处理下,玉米叶片净光合速率升高,O2-.产生速率、H2O2含量下降,MDA含量、相对电导率减小,SOD、CAT、POD活性增强,玉米百粒重和穗粒数增加;而在O3浓度为(80±10)nmo.lmol-1的条件下,玉米叶片净光合速率下降,O-2.产生速率、H2O2含量升高,MDA含量、相对电导率增大,SOD、CAT、POD活性减弱,玉米百粒重和穗粒数降低;CO2和O3浓度升高复合((550±20)μmo.lmol-1+(80±10)nmo.lmol-1)处理下,玉米叶片的净光合速率、H2O2含量、SOD活性先升高后降低,MDA含量、相对电导率、CAT活性增加,POD活性减弱,而O-2.产生速率几乎不变化,且玉米的百粒重和穗粒数略低于对照。以上结果说明,CO2浓度升高抑制了玉米叶片活性氧的代谢速率,提高了抗氧化酶的活性,从而增强了光合作用,使玉米籽粒产量增加,对玉米表现为保护效应,而O3浓度升高促进了玉米叶片活性氧的代谢速率,降低了抗氧化酶的活性,抑制了光合作用,使玉米籽粒产量下降,对玉米表现为伤害效应。在CO2和O3浓度升高复合处理下,CO2浓度升高在一定程度上缓解了O3浓度升高对玉米的伤害效应,而O3浓度升高亦在一定程度上削弱了CO2浓度升高对玉米的保护效应。更多还原

【Abstract】 In order to reveal effect mechanism of elevated carbon dioxide(CO2)and ozone(O3)concentration singly and in combination on plants reactive oxygen species(ROS)metabolism and anti-oxidative enzymes activities,open top chambers(OTCs) were utilized to investigate the change of ROS production rate,content,lipid peroxidation extent,anti-oxidative enzymes activities net photosynthetic rate in maize(Zea mays L.)leaves and grains yield under elevated CO2 and O3 concentration singly and in combination treatment.The results indicated that elevated CO2 concentration((550±20)μmol·mol-1)induced a decrease on superoxide anion(O-·2) production rate,hydrogen peroxide(H2O2)content,content of malondialdehyde(MDA),relative electrical conductivity and a increase on net photosynthetic rate and the activities of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD)in maize leaves and also a elevation on one-hundred-grain weight,grains number of per spike during the whole growth stage.While elevated O3 concentration exposure(80±10nmol·mol-1)showed the opposite effects,which resulted in higher O-·2 production rate,H2O2 content,content of MDA,relative electrical conductivity and lower net photosynthetic rate and activities of SOD,CAT,POD and a reduction on one-hundred-grain weight,spike grains number of maize compared with the control.But under CO2 and O3 concentration combined((550±20)μmol·mol-1+(80±10)nmol·mol-1)treatment,compared with the control,the net photosynthetic rate,H2O2 content,SOD activity were higher earlier and lower later during the growth stages,content of MDA,relative electrical conductivity,CAT activity were enhanced and POD activity was weakened,O-·2 production rate was almost unchanged in the leaves of maize,while one-hundred-grain weight and grains number of per spike in maize increased unsignificantly.The results show that ROS metabolism rates are restrained and anti-oxidative enzymes activities,photosynthesis,grains yield are enhanced by elevated CO2 concentration,which presents protective efficacy on maize,while elevated O3 concentration accelerats ROS metabolism rates,reduces anti-oxidative enzymes activities,photosynthesis and grains yield,which represents injured effects to maize.In combination of elevated CO2 and O3 concentration,the beneficial effects of CO2 on maize are more than compensating the negative effects imposed from O3,and the latter in its turn partly counteracted the positive effects to maize of the former.更多还原