Electron Microscope Investigations on the Stromacentre

Abstract

Some preliminary results are given. Fibrils of the «stromacentre» in basil chloroplasts appear in the first stage of leaf development, then successively they increase, but disappear again in the adult leaves. However, near veins some cells contain «peculiar» chloroplasts very rich in stromacentres, even when these structures have disappeared from the «normal» chloroplasts of the same leaf. Structural analogies between the stromacentres in chloroplasts of both healthy and LMV infected basil, and those of oat coleoptiles are shown: 1) the fibrils have the same thickness (85–90 Å); 2) longitudinally they have a recurring structure; 3) they seem to be grouped into small packets of threes or fours. After five hours treatment with trypsin the stromacentre of oat coleoptile chloroplasts is almost completely destroyed. This could indicate the proteic nature of the fibrils.