Studies on Morphogenesis in Rice Plant : XIII. Ultrastruture of root cap

[摘要] Root caps of rapidly elongating roots of rice plants, grown in water or paddy, were fixed with glutaraldehyde and post osmic acid, and were embedded in Spurr's resin. Ultra-thin sections were stained with uranium and lead to be observed by an electron microscope. Aspects of cell organelles of the rice root caps resemble closely to those of Zea mays. The cells in the peripheral part of the rice root cap have abundunt mitochondria, rough endoplasmic reticulum and Golgi apparatus. The forming dictyosome cisterna of the Golgi apparatus is composed of branched tubules, carrying sometimes the primary vesicles. These primary vesicles are thought to be produced on the smooth membrane side of rough endoplasmic reticulum near the forming face of dictyosome. The maturing cisternae manufacture large Golgi vesicles (secretory vesicles). The endoplasmic reticulum connect with the forming cisterna tubules and the transitional cisternae. Some terminal sacks of the endoplasmic reticulum accumulate dense materials, which are delivered to plasma membrane as well as the Golgi vesicles, and the contents of these vesicles are secreted out of the plasma membrane by exocytosis. Besides, the endoplasmic reticulum connect directly with plasma membrane and may be thought to secrete some materials. The fibrillar secretory materials precipitate in both sides of the cell walls and thereafter disperse out to mucilage. A scheme is drawn based on the observations of the rice root caps, and a transfer mechanism is speculated by confering the reports of Zea mays.

[学科分类] 农业科学（综合）