摘要
用焦锑酸钾沉淀的电镜细胞化学方法 ,研究了低温胁迫下枇杷幼叶细胞内 Ca2 + 水平变化。研究结果表明 ,枇杷幼叶细胞未经低温处理时 ,Ca2 +定位分布的沉淀颗粒大量出现在细胞壁、细胞间隙、质膜和液泡 ;叶绿体、细胞质和细胞核中也有一些 Ca2 +沉淀颗粒分布。枇杷幼叶经 44h、4℃低温处理后 ,在质膜和液泡膜上 Ca2 + 的沉淀增多 ,细胞质和细胞核中的Ca2 +水平增加。不抗寒品种在低温胁迫条件下可见核孔开口较大 ,有时可观察到核内容物外漏。抗寒品种在低温胁迫条件下核孔未见明显开口 ,叶绿体中类囊体不形成基粒 ,少数片层结合重叠后伸展在整个叶绿体中。而不抗寒品种类囊体则堆积形成明显的颗粒状基粒 ,类囊体片层数量较多。在 2个叶绿体之间还常可见到线粒体紧夹其间 ,但线粒体的内膜模糊不清。不抗寒品种内质网和高尔基体也较多见 ,内膜系统比较发达 ,但低温胁迫条件下膜系统易受破坏 ,膜结构模糊不清。
The changes of Ca 2+ localization in cells of loquat( Eriobotrya japonica Lindl.) leaflets under chilling stress were investigated with calcium antimonate precipitate electromicroscopic cytochemical methods.When loquat leaflets grew at the optimum temperature,it was shown that the deposits of calcium antimonate,being the indicator for Ca 2+ localization,mainly concentrated within the vacuoles and intercellular spaces,and that there was also some Ca 2+ deposits in plastid,mitochondria,cytoplasm and nucleus.This indicates that under the normal condition,the vacuoles are the main pool of Ca 2+ in plant cells,and that there is quite an amount of Ca 2+ in the intercellular spaces.On the contrary,the free Ca 2+ in cytoplasm and nucleus is very low under the normal condition.When the loquat leaflet was treated at the temperature of 4℃ for 44 hours,the level of Ca 2+ in cytoplasm and nucleus increased considerably.Under the chilling stress,there are a great amount of Ca 2+ deposits in vacuolar,chloroplast,plasma membrane and vacuole membrane.The membrane of nucleus in the cold sensible variety had been damaged and some nuclear substance let out.There were only stroma thylakoids in the cells of cold resistant variety,while many basal granules in the cold sensible variety.The membrane of chloroplasts had been damaged.
出处
《武汉植物学研究》
CSCD
2000年第2期138-142,共5页
Journal of Wuhan Botanical Research
基金
福建省教委科学研究基金资助项目!(编号 :K950 1 7)
关键词
枇杷
低温胁迫
细胞化学
细胞超微结构
CA^2+
Calcium cytochemistry
Calcium messenger
Eriobotrya japonica
Plant cold resistance
