低温胁迫对两种圆柏属植物亚细胞抗氧化酶活性的影响

以祁连圆柏和圆柏幼苗为材料,研究不同处理时间下低温胁迫对圆柏属植物叶片亚细胞抗氧化酶活性的影响,探讨其在圆柏属植物叶片中的亚细胞定位。结果表明：低温胁迫下,丙二醛(MDA)含量和抗氧化酶活性随时间变化均呈先升后降趋势,祁连圆柏中抗氧化酶的种类比圆柏的多且活性强,而 MDA 含量低于圆柏,表明祁连圆柏在低温胁迫下具有更广泛的适应性。此外,两种圆柏植物叶片超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)定位为叶绿体＞细胞溶质＞线粒体,过氧化氢酶(CAT)定位为线粒体＞叶绿体＞细胞溶质,谷胱甘肽还原酶(GR)定位为线粒体＞细胞溶质＞叶绿体,祁连圆柏过氧化物酶(POD)定位为细胞溶质＞叶绿体＞线粒体,圆柏POD定位为细胞溶质＞线粒体＞叶绿体,且抗氧化酶SOD、APX和 GR在亚细胞中分布差异达到极显著,这说明抗氧化酶在其中一种亚细胞中发挥主要作用,为克隆亚细胞组分中的抗氧化酶基因提供了理论依据。

Effects of low temperature stress on antioxidant enzymes activities in the subcellular of two Sabina species

Seedlings of Sabina przewalskii and S. chinensis were used to study the effects of low temperature stress on antioxidant enzymes activities and subcellular distribution in the leaves of Sabina. The results showed that: under low temperature stress, the contents of malonaldehyde(MDA)and antioxidant enzymes activities increased firstly and then decreased, and compared with Sabina chinensis, the more species and higher activities of antioxidant enzymes were found in S. przewalskii, but MDA contents of S. przewalskii were lower than S. chinensis,it suggested that S. przewalskii showed a prevailing strategy than S. chinensis in order to develop the tolerance to freezing. Moreover,the localization of superoxide dismutase(SOD)and ascorbate peroxidase(APX)in the leaves of two Sabina species was chloroplast>cytosol>mitochondria,the localization of catalase(CAT)was mitochondria>chloroplast>cytosol,the localization of glutathione reductase(GR)was mitochondria>cytosol>chloroplast,the localization of peroxidase(POD)in S. przewalskii was cytosol>chloroplast>mitochondria,the localization of POD in S. chinensis was cytosol>mitochondria>chloroplast,moreover subcellular distribution of antioxidant enzymes(SOD,APX,GR)in organelles were different significantly,this showed that antioxidant enzymes played a major role in one of organelles,which provided theoretical basis for cloning of antioxidant enzymes gene in subcellular fractions.