NaCl胁迫对宁夏枸杞叶和幼根显微及超微结构的影响

Effect of NaCl Stress on the Microstructure and Ultrastructure of Leaves and Young Roots in Lycium barbarum

以宁夏枸杞为材料,采用超薄切片技术制备样品,应用光学显微镜和透射电镜分析了不同浓度NaCl胁迫条件下宁夏枸杞叶和幼根显微及超微结构的变化。结果表明:随着NaCl胁迫的加重,(1)叶片上表皮细胞增厚,栅栏组织细胞出现缩短现象,排列疏松且紊乱;幼根的初生结构无明显变化。(2)叶片栅栏组织中叶绿体不再紧靠在细胞膜上,叶绿体双层膜破坏,基粒片层松散排列,杂乱无章,出现膨胀和空泡现象,淀粉粒和嗜锇颗粒增多,叶肉细胞中线粒体发生轻微变化;幼根中皮层薄壁细胞线粒体形状发生改变,结构破坏,内膜和外膜模糊甚至破裂,大多数嵴模糊,出现空泡现象;细胞核解体,基质外溢。研究表明,不同浓度的NaCl胁迫对宁夏枸杞叶片和幼根细胞的显微及超微结构影响不同,NaCl浓度大于200 mmol/L时,宁夏枸杞叶片和幼根细胞的显微及超微结构发生了明显变化,且叶肉细胞中线粒体的变化没有叶绿体的变化显著,推测叶肉细胞中线粒体的耐盐性比叶绿体强。

In this study,Lycium barbarum was use as experimental material,ultra-thin section technique,microscopy and transmission electron microscopy were employed to analyze the changes of microstructure and ultrastructure of leaves and young roots of L.barbarum under different NaCl concentrations.The results showed that,with the increase of NaCl concentration,(1)the upper epidermal cells of the leaf became thicker,and the cells of fenestrations tissue appear shortened,became loose and disordered,the primary structure of the young roots did not change significantly.(2)The chloroplasts in fenestrated tissues of the leaves no longer adhered to the cell membrane,the double layer membrane of chloroplasts was damaged,the basal lamellae was arranged loosely,disorganized,swollen and vacuolated,the number of starch grains and osmiophilic granules increased,slight changes in mitochondria in chloroplasts.The shape of mitochondria in the cortical cells has changed,the structure was damaged,the inner and outer membranes were blurred or even ruptured,most cristae were blurred,vacuolation was occurred.The cell nucleus disintegrated and the content matrix flowed out.The study showed that different concentrations of NaCl stress had different effects on the microstructure and ultrastructure of the leaves and young roots of L.barbarum.The microstructure and ultrastructure of the leaves and young roots of L.barbarum were significantly changed at NaCl concentrations greater than 200 mmol/L.The changes of mitochondria in the leaf pulp cells were not as significant as those of chloroplasts,and it was assumed that the salt tolerance of mitochondria in the leaf pulp cells was stronger than that of chloroplasts.