PVA和PEG预处理对大豆种子在低温吸胀过程中胚根线粒体发育和超微结构的影响

电镜观察发现,大豆种子在刚开始萌发时胚根细胞中未能见到线粒体,线粒体是在种子萌发过程中逐渐出现的,由原质体再分化发育而成。对照胚根细胞内原质体在低温吸张过程中明显膨胀,在回温后胚根细胞中原质体仍不能发育成线粒体,甚至网状膜结构破坏,呈空泡化;经聚乙烯醇(PVA)和聚乙二醇(PEG 6000)预处理的大豆种子在同样条件下线粒体能继续发育,在回温后预处理胚根细胞中线粒体发育良好,具有明显的双层膜和管状嵴的结构。这些结果表明,在低温吸胀过程中原质体能够继续再分化发育成线粒体是提高大豆种子活力和抗冷力的重要原因。

EFFECTS OF PVA AND PEG PRETREATMENT ON DEVELOPMENT AND ULTRASTRUCTURE OF PLUMULAR ROOT MITOCHONDRIA IN SOYBEAN SEED DURING LOW TEMPERATURE IMBIBITION PROCESS

Electron microscope observation revealed that mitocbondria in plumular root cells of soy- bean seed were invisible at the beginning of seed germination.They were sequentially formed re-differentiated and developed from proplastids during the process of germination.The pro- plastids in the control plumular root markedly expanded at low temperature imbibition process and did not develop into mitochondria when normal temperature was restored.Even the struc- ture of reticulata membrane was further destroyed and vacuolized.In contrast,mitochondria of soybean seed pretreated with polyvinyl alcohol(PVA)and polythylene glycol-6000(PEG)con- tinused to develop well under the same conditions,as characterized by a clear structure of bilayered membrane and tube cristae.The results suggest that continuous re-differentiation and development of proplastids into mitochondria at low temperature imbibition process play an im- portant role in the increase of soybean seed vigour and its resistance to chilling injury.