作　　者： ; ; ;

机构地区： 岭南师范学院生命科学与技术学院广东湛江524048

出　　处： 《农业环境科学学报》 2019年第12期2697-2704,共8页

摘　　要： 为研究镉胁迫对高低积累型水稻幼苗非蛋白巯基(Non-protein thiols, NPT)物质含量的动态变化影响规律,利用营养液沙培盆栽实验,设置镉浓度为50μmol·L^-1,分别监测处理前(0 d)和处理后第1、3、5、7 d水稻的过氧化程度和非蛋白巯基物质含量。结果表明:随镉胁迫时间的延长,两品种水稻的过氧化氢(Hydrogen peroxide,H2O2)和硫代巴比妥酸反应产物(Thiobarbituric acid reactive substances,TBARS)含量逐渐上升,且镉低积累型品种优I2009的H2O2和TBARS含量上升的幅度大于镉高积累型品种欣荣优2045,其中欣荣优2045地上部H2O2和TBARS含量上升的幅度分别为45%和74%,其根系上升的幅度分别为1.14倍和61%,而优I2009地上部H2O2和TBARS含量上升的幅度分别为78%和1.20倍,其根系上升的幅度分别为1.32倍和64%,说明镉低积累型品种优I2009遭受的氧化胁迫水平和膜脂过氧化程度大于镉高积累型品种欣荣优2045。欣荣优2045的还原型谷胱甘肽(Reduced glutathione,GSH)随镉胁迫时间的延长逐渐增加,而优I2009的GSH呈先升后降的趋势;两品种水稻的NPT、植物螯合肽(Phytochelatins,PCs)含量和谷胱甘肽硫转移酶(Glutathione S-transferase,GST)活性随镉胁迫时间的延长呈先升后降的趋势,且欣荣优2045合成的NPT含量和生成的GST活性更高。研究表明,镉高积累型水稻品种可以通过合成更多的含巯基的非蛋白化合物与镉络合来清除活性氧,进而增加对镉的耐性。 In order to better understand the influence of cadmium(Cd)stress on non-protein thiols(NPT)compounds in the seedlings of high-and low-Cd-accumulating rice cultivars, a pot experiment was conducted. In the experiment, 50 μmol·L^-1 Cd^2+was set up, the peroxidation degree and NPT content were to be monitored regularly at before treatment(0 d), at 1 st, 3 rd, 5 thand 7 thd after treatment. The results showed that the contents of hydrogen peroxide(H2O2)and thiobarbituric acid reactive substances(TBARS)in the two cultivars induced by Cd showed an increasing trend over time, and the extents of variation for H2O2 and TBARS content in You I2009(low-Cd-accumulating rice cultivar)were greater than that in Xinrongyou 2045(high-Cd-accumulating rice cultivar), proving with data that the extents of variation for H2O2 and TBARS contents in Xinrongyou 2045 cultivar were 45% and 74% for shoots, and 1.14 folds and 61% for roots, respectively, while they were 78% and 1.20 folds for shoots, and 1.32 folds and 64% for roots in You I2009 cultivar. It indicated that You I2009 suffered more oxidative stress and membrane lipid peroxidation than Xinrongyou 2045. An increasing pattern in reduced glutathione(GSH)content of Xinrongyou 2045 were induced by Cd stress over time while for You I2009, the GSH contents increased first and then decreased.The NPT content, phytochelatins(PCs), and glutathione S-transferase(GST)in the two cultivars increased first and then decreased over time under Cd stress, and the NPT contents and GST activities of Xinrongyou 2045 were higher than that in You I2009. These results indicate that high-Cd-accumulating rice cultivar can eliminate reactive oxygen species by synthesizing more sulfhydryl nonprotein compounds chelating with cadmium.

关 键 词： 镉胁迫 水稻 非蛋白巯基化合物 还原型谷胱甘肽 植物螯合肽 谷胱甘肽硫转移酶

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