Chloroplast development in isolated roots of Convolvulus arvensis (L.).

The fine structure of chloroplast development is described for isolated roots of Convolvulus arvensis. Stages in the transition from the leucoplast, characteristic of dark-grown roots, to the chloroplast, found in light-grown roots, are defined and related to chlorophyll content of the root tissue. The interdependence of tissue type and organellogenesis has been investigated for three tissues in the primary root: cortical parenchyma, pericycle and stelar parenchyma tissue. Plastids in cells of all three tissues follow the same sequence of chloroplast development, although the rate of development is dependent on the tissue type.