OBSERVATIONS ON THE MECHANISM OF CHLOROPLAST DIVISION IN HIGHER PLANTS

Abstract

SUMMARY The sequence of changes in membranes that occur during the division of young green chloroplasts is described from observations in the electron microscope of thin sections of leaf tissue of Triticitm aestivum var. Maris Dove, Atriplex semibaccata R.Br. and Sesamum indicum var. glauca. Comparative observations of the morphological forms of dividing chloroplasts present in suspensions from young wheat leaves were made using phase contrast and Nomarski interference optics and from thin sections. The isthmus region of the dividing chloroplasts has a similar form in all three species and fuzzy plaques of electron opaque material and some invaginations in the isthmus were frequently observed. The significance of these fuzzy plaques is discussed and a possible mechanism for chloroplast division suggested.