Abstract
Chloroplast transformation is employed in basic research and green biotechnology. Using chloroplasts as bioreactors provides several advantages such as solar-powered high transgene expression, easy gene-targeting in the plastid genome by homologous recombination, increased biosafety due to tight transgene containment and the potential of engineering metabolic pathways in operon-like arrangements. These and other features make chloroplasts attractive for genetic engineering and biotechnology.