摘要
逆境条件下活性氧产生及其清除效率是衡量植物抗性的重要指标,而活性氧对植物组织的氧化伤害和抗氧化酶活性常因材料的遗传或生理差异性而发生变化。以同一基因型的野牛草(Buchloe dactyloides(Nutt.)Engelm'texoka')克隆分株叶片为材料,采用Hoagland营养液培养,研究了10%、20%和30%PEG-6000模拟干旱胁迫下,野牛草叶片活性氧的产生、脂质过氧化和抗氧化酶活性变化规律。结果表明:随着PEG-6000浓度的增加及胁迫时间的延长,超氧阴离子(O2-.)的产生速率、过氧化氢(H2O2)和丙二醛(MDA)含量均显著增加;超氧化物歧化酶(SOD EC1.15.1.1)、愈创木酚过氧化物酶(G-POD EC1.11.1.7)和过氧化氢酶(CATEC1.11.1.6)活性呈先上升后下降的变化趋势;SOD、G-POD与CAT活性达到峰值的时间随PEG-6000浓度的增加而提前。认为水分胁迫下,抗氧化酶可有效清除活性氧自由基,但随胁迫时间的延长,抗氧化酶活性受到抑制。
The time course of reactive oxygen generation in plants under stress and the corresponding mechanisms of alleviation in plants are often used as an important indicator for evaluating stress tolerance.However,the quantification of the reactive agents and enzymes is complicated by genetic variations in experimental materials.Clones of ＇texoka＇ buffalograss（Buchloe dactyloides（Nutt.）Engelm）were cultured in a hydroponic system to investigate the efficts of reactive oxygen,lipid peroxidation,and antioxidase activities in leaves under physiological drought stress induced by high PEG-6000 concentration in the cultural solution.Superoxide radical（O-·2）,hydrogen peroxide（H2O2）,and malondlaldehyde（MDA）in the leaves were quantitatively regressive to the concentration of PEG-6000 over the time course.On the other hand,the activities of superoxide dismutase（SOD EC 1.15.1.1）,guaiacol peroxidase（G-POD EC1.11.1.7）,and catalase（CAT EC 1.11.1.6）in the leaves showed pulses,increasing at the early stage and then decreasing gradually to the level of the control.The occurrence of peak activities of SOD,G-POD and CAT in the leaves was earlier with increased stress intensity.These results indicated that both the time course and quantities of the antioxidase in buffalograss are important for evaluating the defense response against oxidation damage induced by water stress.Therefore,sampling time as well as the quantification of the antioxidase has to be considered for better understanding the stress response system in buffalograss.
出处
《生态学报》
CAS
CSCD
北大核心
2010年第7期1920-1926,共7页
Acta Ecologica Sinica
基金
国家高技术研究发展计划(863)资助项目(2007AA100105
2006AA100109)
关键词
野牛草
水分胁迫
活性氧
脂质过氧化
抗氧化酶
Buchloe dactyloides ＇texoka＇
water stress
reactive oxygen species
lipid peroxidation
antioxidase
