低温胁迫过程中北海道黄杨叶肉细胞Ca^(2+)的动态变化

Dynamic Changes of Ca^(2+) in the Mesophyll Cells of Euonymus japonicus cv.'CuZhi' under Low Temperature Stress

用焦锑酸钙沉淀的电镜细胞化学方法,研究露天生长的北海道黄杨低温胁迫过程中叶肉细胞Ca2+的动态变化。结果表明:与夏季的叶肉细胞相比,从11月份到翌年1月期间,Ca2+沉淀颗粒起初主要分布在细胞间隙和液泡,细胞质中有少量的Ca2+沉淀颗粒,大多数叶绿体中的淀粉粒消失,嗜锇颗粒增加;随后逐渐变化为胞间隙和液泡中Ca2+沉淀颗粒减少,而细胞质基质的Ca2+沉淀颗粒显著增加。在此期间叶肉细胞的一些叶绿体膜泡化,出现解体现象;线粒体的数量增加;中央大液泡变成数个小液泡。低温胁迫过程中叶肉细胞Ca2+的浓度和分布的变化与细胞超微结构的变化存在一定的相关性。

Dynamic changes of Ca2＋ in the mesophyll cells of outdoor Euonymus japonicus cv.＇CuZhi＇ under low temperature stress were investigated with a calcium antimonate precipitate-electromicroscopic-cytochemical method.Results showed that in the beginning the calcium particles in the mesophyll cell,from November 2010 to January 2011,mainly resided in intercellular spaces and vacuoles with a small number of calcium particles in the cytoplasm compared with those in summer conditions.Starch grains disappeared in most of the chloroplasts while more osmilphilic granules appeared.After then the number of calcium particles in intercellular spaces and vacuoles gradually decreased,whereas the particles in the cytoplasm significantly increased.Simultaneously,part of chloroplast membrane vesicled and began disintegration,more mitochondria emerged,and the central vacuole was divided into small vacuoles.Thus it could be concluded that there is a certain correlation between the changes of calcium distribution and concentration and the changes of the cell ultrastructure under low temperature stress.