干旱胁迫对银沙槐幼苗叶绿体和线粒体超微结构及膜脂过氧化的影响  

Effects of Drought Stress on Ultrastructure of Chloroplast and Mitochondria and Membrane Lipid Peroxidation of Ammodendron argenteum

作　　者：徐萍[1] 李进[1] 吕海英[1] 李永洁[1] 李佳[1] 马春兰[1] 

机构地区：[1]新疆特殊环境物种保护与调控生物学实验室新疆师范大学生命科学学院,新疆乌鲁木齐830054

出　　处：《干旱区研究》2016年第1期120-130,共11页Arid Zone Research

基　　金：国家自然科学基金项目(31160094);新疆维吾尔自治区教育厅重点实验室"新疆特殊环境物种多样性应用与调控重点实验室"项目(XJSD2013-01);新疆师范大学研究生创新基金项目(20121207)资助

摘　　要：以沙生植物银沙槐(Ammodendron argenteum)幼苗为实验材料,利用透射电镜技术,结合丙二醛(MDA)和细胞膜透性的测定,观察干旱胁迫对银沙槐子叶期幼苗的叶肉细胞及下胚轴细胞超微结构的变化,分析干旱胁迫对银沙槐幼苗细胞超微结构和膜脂过氧化的影响。结果显示:随着干旱胁迫的加剧,叶绿体变形、外被膜波浪状、断裂不完整。同时,基粒和基质类囊体膜结构模糊,基粒弯曲、膨胀、排列混乱;线粒体膜完整性低、内部嵴消失、空泡化。细胞膜透性和膜脂过氧化产物MDA含量均升高,显著高于对照(P<0.05),细胞膜结构受到破坏,细胞膜脂过氧化作用增强。子叶的细胞膜透性和MDA含量显著高于下胚轴(P<0.05),细胞器形态变化早于下胚轴,表明下胚轴耐旱性相对于子叶较强。子叶中线粒体受损晚于叶绿体,线粒体的耐旱性要比叶绿体强。不同组织间及同一组织不同细胞器之间对干旱胁迫反应的差异,可能是植物组织细胞应对外界不利环境的一种防御反应。干旱胁迫下超微结构的变化反映了细胞内膜系统的紊乱和伤害,而膜系统的伤害可能是脂质过氧化作用增强的结果。Ammodendron argenteum is unique rare and endangered desert plant in Xinjiang. There are research evidences showing its growing traits and physiological characteristics and so on,however research is lacking to understand the response of ultrastructure under drought stress. Using transmission electron microscopy and measurement of MDA content and membrane permeability,the change on ultrastructure of mesophyll cells and hypocotyl cells of Ammodendron argenteum seedlings were observed. And the effects of drought stress on ultrastructure and membrane lipid peroxidation were analyzed. The result showed that chloroplasts deformed,outer membranes were wavy and incomplete. In the meanwhile,membrane structures of grana and stroma-thylakoids blurred,grana bent and dilated. The mitochondrion outer membranes were disrupted and cristaes disappeared,and the lumen formed a cavity. The membrane permeability and MDA content increased and significantly higher than the control（ P〈 0. 05）,cell membrane structure were damaged,the effects of membrane lipid peroxidation intensified. Membrane permeability and MDA content of cotyledon cells increased and significantly higher than those of hypocotyl cells（ P 〈0. 05）,and the changes of ultrastructure in cotyledon cells was earlier than hypocotyl cells,which showed that drought tolerance of hypocotyl stronger than cotyledon ＇s. Mitochondrial damaged later than chloroplasts in cotyledon which showed that drought tolerance of Mitochondrial stronger than chloroplasts＇. The responsive difference under drought stress between different structures and different organelles in the same structure may be a kind of defense reaction which plant tissue cells have in the adverse environment. The change of ultrastructure under drought stress reflected the disorder and damage of intracellular membrane systems,and the damage of the membrane systems might be the result of intensified lipid peroxidation.

关 键 词：银沙槐(Ammodendron argenteum) 干旱胁迫 叶绿体 线粒体 超微结构 膜脂过氧化 

分 类 号：Q945.78[生物学—植物学]