The Effect of Genetic Factors on the Submicroscopic Structure of Soybean Chioroplasts

Abstract

1. The development of chloroplasts in normal and in chlorophyll-deficient yellow lethal (y11y11) specimens of the soybean (Glycine max (L.) Merril) was studied with the electron microscope.2. The steps in the differentiation of normal soybean chloroplasts are similar to those found in other seed plants, ferns and mosses, namely: (1) the formation of vesicles from the inner of the two membranes of the proplastids, (2) the construction of primary lamellae by the fusion of the vesicles, (3) the building up of discs and the aggregation of the discs to form grana, (4) the increase in the number of grana and their interconnection by stromatic lamellae.3. In the development of the chlorophyll-deficient chloroplasts of the mutant, vesicle formation and fusion of vesicles to form primary lamellae appear to proceed normally in the proplastids; sometimes grana are formed. But either the arrangement of the lamellae in the later stages of development is abnormal, or the lamellae break down and vacuolization of the chloroplast ensues.