The present invention relates to a plastid transformation system capable
of preventing second recombination events of heterologous genes inserted
into plastid genomes. More specifically, this invention relates to a
plastid transformation vector carrying a promoter and a terminator
derived from organisms other than tobacco. The inventive recombinant
expression vector for plastid transformation is capable of mass-producing
exogenous proteins on a level par with conventional vectors carrying
promoter/terminator couples of tobacco origin. At the same time, it is
capable of preventing second recombination events within plastids. Thus,
the vector of this invention is greatly useful in producing transgenic
plants since it can effect a secure introduction of heterologous genes
and support normal transformation and heterologous gene expression.