微波预处理对镉胁迫引起小麦幼苗脂质过氧化伤害的防护作用

摘要

A hydroponic experiment was conducted to study the changes of growth and physiological reaction of wheat seedlings exposed to 150 μmol/L Cd2+ stress, which was pretreated by microwave (wave length 125 mm, power density 126 mW/cm2, 2 450MHz). The results showed that Cd2+ stress inhibited the growth of wheat seedlings, and increased the malonrndialdehyde (MDA)、 H2O2 content and the production rate of ·O-2, while decreased the antioxidative enzymes, antioxidative compounds and photosynthetic pigment content in leaves of wheat seedlings. Microwave pretreatment of 5 s, 10 s had positive effect on wheat seedlings subjected to cadmium stress, such as decreasing the concentration of MDA、 H2O2 and the production rate of ·O-2; increasing the activity of SOD, POD, CAT, concentration of AsA, GSH, chlorophyll a, chlorophyll b, carotinoid, chlorophyll (a+b), plant height and root length. It was suggested that those changes in MDA, H2O2, -0"2, antioxidative enzymes, antioxidative compounds and photosynthetic pigment were responsible for protecting wheat against cadmium induced oxidative damage.%采用水培试验在150 μmol/L Cd2+溶液胁迫下研究外源微波预处理对小麦幼苗生长和生理特性的影响.试验结果表明:①镉胁迫下,小麦幼苗生长受到抑制,叶片丙二醛(MDA)含量、过氧化氢(H2O2)含量及超氧自由基(·O2-)产生速率显著增加(P＜0.05),抗氧化酶活性、抗氧化物质含量及叶绿素含量显著降低.②微波预处理5s和10s均能显著提高镉胁迫下小麦幼苗的生长；同时抑制镉胁迫下小麦幼苗叶片MDA含量、H2O2含量及超氧自由基(·O2-)产生速率的上升,显著提高(P＜0.05)超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)活性,增加谷胱甘肽(GSH)、抗坏血酸(AsA)、叶绿素a、叶绿素b、类胡萝卜素及叶绿素(a+b)含量.表明外源微波预处理可缓解镉胁迫对小麦幼苗生长的抑制作用,缓解镉胁迫引起的膜脂过氧化,保护细胞膜减少或免受损伤,提高植物抗镉胁迫的能力.