Relationship of Cellular Organelles to the Formation and Development of the Plant Cell Wall

Abstract

It has been shown that Golgi bodies, endoplasmic reticulum, and microtubules are concerned with the organization and synthesis of materials which are incorporated into the wall of the many cells making up the various tissues of a young plant. Preformed material is added to the wall from vesicles which in some cells can be inferred to be derived from the Golgi bodies. The material is passed to the wall by a process of pinocytosis. In other cells although the same process is apparent the origin of the vesicles cannot at present be ascertained. The organization of the growth and development of the wall is controlled to some extent by the endoplasmic reticulum which can be seen to be situated in the cell at positions relative to particular regions of cell-wall development. This is very apparent in the formation of pit fields, sieve plates, and the secondary thickenings of the xylem. The microtubules are organized in the cytoplasm relative to wall growth and can be seen in cells in which growth is either occurring uniformly along the wall or as organized annular or spiral thickenings. In the former case the microtubules are also present all along the length of the wall whereas in the latter cells they are found grouped in relation to the developing thickenings.