油菜叶肉细胞中特殊管泡状结构的形成及其与干旱的关系

THE TUBULI-VESICULAR STRUCTURE IN MESOPHYLL CELLS OF RAPE PLANTS GROWN IN DRY CONDITION

在干旱情况下,油菜叶肉细胞会出现一种特殊的管泡状结构,这种结构仅由许多管状成分和泡状物质组成。它的外面还有一层包膜。它可能由质膜变化而来,并且在干旱条件下逐渐发育增大,结构日趋复杂。这种结构可能是一种溶酶体,在细胞质中能促进细胞内物质的水解,同时在液泡中被其他酶所消化。故能提高液泡中溶质的浓度,减少水分外渗,对于防止细胞过度失水有一定作用。因此,这种结构可能对于植物的抗旱性有重要意义。

Rape is an important oil-bearing crop and very sensitive to drouhgt. Ultrastructural changes occurred in the mesophyll cells of rape plants which grow in dry condition were observed. In the mesophyll cells a tubuli-vesicular Structure can be found when the drought is developed. But the Structures were never occurred in the cells of control plants. At the beginning of drought the structures appeared near to plasma membrane then on the tonoplast membrane of central vacuoles, and connected with the membrane. The structure is composed of a layer membrane envelope and contained many tubular elements and vesicular materials which derived from the formers.There are not other elements of cytoplasm in it. These special structures, maybe, come from the plasma membrane rather than other organelles. Along with the development of drought the structures gradually moved into the cental vacoules and became larger and more complex in structure than before. The structures, perhaps, are a kind of lysosomes,and have some functions of provenring the cells from over-lossing water in the drought stress condition. So the structures are supposed to be related to the plant resistance to drought condition.