On the Formation of Root Hairs in Crown Roots of Rice Plants Especially on the Fine Structure of Epidermal Cells

Abstract

It had been ascertained by the authors that root hairs of the rice plants were formed in the shorter epidermal cells, and the shorter epidernlal cells were richer in ribonucleic acid (RNA) than longer epidermal cells. But, the study on the root hair formation by observing the fine structure of the epidermal cells, especially cultured at soil condition, has not been conducted. The present work was carricd out to study the root hair formation by observing the fine structure of the epidermal cells of the crown roots cultured under soil condition. The following results were obtained: Generally, the epidermal cells which will be hair forming cells have larger nuclei than those which will not be, particularly at the early stage of the elongation zone. At this stage, authors could not distinguish the root hair forming epidermal cells from the other cells by measuring their cell-length. As regards the fine structures of the epidermal cells, the epidermal cells which will be hair forming cells have more ER (endoplasmic reticulum), mitochondria, and ribosome than those which will not be, when they measured on the same area. These differences were also ascertained at the early stage of the elongation zone of root.