Changes in envelope permeability during chloroplast development.

The permeability of the plastid envelope during the development of Avena sativa plastids was investigated by light scattering and uptake of various labelled compounds (malate, succinate, glutamate, α-ketoglutarate, citrate, glycine, sucrose). The results presented show that a primary event during greening is a change in permeability, thereby allowing an increased transport of metabolites across the membranes of very early etio-chloroplast stages. The results are discussed in view of an adaption of the plastid envelope permeability to the changing requirements of externally synthesized precursors and intermediates during development.