冬季沙冬青液泡中膜状内含物的超微结构研究

冬季沙冬青叶肉细胞中由于液泡膜内吞现象极其普遍，以致常常形成各种细胞质突起，并有丰富的颗粒状和纤维状物质及大量的膜状结构存在于液泡中。膜状结构大小不等，形态各异，膜层排列也不一样。有的相当紊乱，有的比较规则，有的甚至呈同心圆形。同心圆的内部膜层时而清楚，时而模糊，时而是一团电子密度很高的物质。在这些液泡中常有一种电子密度很高，近似圆形的内含物，它的表层中偶尔有膜状结构。冬季沙冬青液泡膜的大量内吞可能与沙冬青具有高度的抗寒性有关。

Ultrastructural studies on menbraneous inclusions in the vacoules of Ammopitanthus mongolicus in winter

Endocytic phenomenon of the vacuoles in the mesophyll cells of Ammopitanthus is very common.Due tothe endocytosis the vacuoles often form various protruberances around them,the protruberances contain cytoplasm or electron-density material or abovementioned two kinds of elements. The vacuoles do not only possessabundant granular-shaped and fibrillar-shaped material but also a large quantity of membrane-shaped structureswhich are different in size,morphology and the arrangement of membrane layers,Some of membrane-shapedstructures are quity disorder,some are regular,some even appear to be concentric circles in the arrangement ofmembrane layers.Somtimes the membranes in the concentric circles are clear,sometimes are unclear, some-times change into an electron-density material.In the same time,there are often some electron-density inclu-sions in the vacuoles,the inclusions usually are proximate round-shaped,occasional there are a small quantity ofmembrane-shaped material in their surface layer parts and there is an electron transparent space in its centralpart.A large quantity of endocytic phenomenon of vacuoles in the mesophyll cells of Ammopitanthus mongoli-cus in winter may be relation with its very high cold resistance.