大气CO_2与O_3浓度升高对毛竹叶片膜脂过氧化和抗氧化系统的影响

Effects of Elevated CO_2 and/or Elecated O_3 on Membrane Lipid Peroxidation and Antioxidant Systems in Phyllostachys edulis Leaves

以盆栽一年生毛竹为材料,利用开顶式气室模拟大气O3和CO2浓度升高情景,分析毛竹叶片细胞膜脂过氧化、抗氧化酶(SOD、CAT、POD和APX)活性和渗透调节物质(可溶性糖和可溶性蛋白)含量的响应规律,为气候变化背景下的竹林适应性管理提供理论支撑。结果表明:(1)短期(30d)高浓度O3(92～106nL.L-1)胁迫能刺激毛竹叶片抗氧化酶活性和渗透调节物质含量显著提高,清除活性氧能力增强,并未出现细胞膜脂过氧化现象,即毛竹对短期高浓度O3具有较强的适应性;但长期(90d)O3胁迫条件下,毛竹叶片抗氧化酶活性显著降低,叶片细胞膜脂过氧化程度加剧,膜结构破坏,发生严重的氧化伤害。(2)短期高浓度CO2(685～730μmol.mol-1)处理总体上对毛竹叶片细胞膜脂过氧化和抗氧化酶系统活性影响并不明显;而长期高浓度CO2处理能一定程度上增强毛竹的抗氧化能力和渗透调节功能,减轻氧化损伤,体现了对毛竹的保护效应。(3)高浓度O3和CO2复合作用下,相对于单一高浓度O3胁迫,毛竹叶片能够维持较高的抗氧化酶活性和渗透调节物质含量,有效地调节活性氧产生与清除间的平衡,细胞膜脂过氧化程度变化不明显,说明高浓度CO2可在一定程度上缓解高浓度O3对毛竹所造成的生理伤害。

This research was conducted to provide theoretical evidence for bamboo cultivation during this time of possible climate change.Open-top chambers（OTCs） were employed to determine the effects of elevated O3（EO）and elevated CO2（EC）alone and in combination on membrane lipid peroxidation and anti-oxidation system in the leaves of Phyllostachys edulis using a split-plot design with treatments of AA,EC,EO,ECEO.The results showed that：（1）After 30 days of exposure,elevated O3 can stimulate the activity of anti-oxidation enzymes（SOD,CAT,POD,APX） and the contents of osmotic adjusting substances（soluble protein and soluble sugar）,which can balance reactive oxygen species production,resulting in no significant increase in malondialdehyde content.Along with the decline of antioxidant,intense the damage to membrane lipid and destroy the structure of cell membrane.（2）Short-term treatment of high concentration of CO2 on membrane lipid peroxidation and antioxidant system in the leaves of P.edulis effect is not evident,and long-term treatment of high concentration of CO2 will increase the antioxidant ability of P.edulis and osmotic adjustment function in a certain extent,and thus,alleviate the oxidative stress.（3）In combination of elevated CO2 and O3,the leaves of P.edulis can maintain high levels of antioxidant enzymes activities and osmotic adjustment substance contents to effectively regulate reactive oxygen species generation and clearing balance,indicating that elevated CO2 could ameliorate the oxidative stress in some extent.