Large scale, rapid preparation of functional mesophyll chloroplasts from Zea mays and other C₄ species

A procedure for the rapid, large scale preparation of leaf mesophyll chloroplasts from Zea mays by mechanical methods is described. Centrifugation through a Percoll density layer is used as a final purification step, yielding chloroplasts showing 80-90% intactness and high rates of substrate-dependent oxygen evolution under illumination. Thus, these chloroplasts are of similar functional integrity to those prepared from C₄ leaf mesophyll protoplasts but the method allows a considerable saving in time and greater yields. The method has been found suitable for mesophyll chloroplast preparation from several other C₄-species.