Vectors for Chloroplast Transformation - Some special plastid transformation vectors, e.g. pZSI48, have been devised. This vector has been designed as a shuttle vector to replicate both in E. coli and chloroplasts. The vector pZS148 was introduced into tobacco leaves by particle gun delivery, and three transformants were recovered.

These plants showed maternal inheritance for resistance to the antibiotics streptomycin and spectionomycin. It was estimated that gene integration in cpDNA was only 1 % of that in nuclear DNA. Stable chloroplast transformation depends on the integration of the transgene into the chloroplast exclusively by homologous recombination.