Current status on plant molecular farming via chloroplast transformation

Abstract Chloroplast transformation in higher plants offers many attractive advantages over nuclear transformation, including a high-level accumulation of foreign proteins, multi-gene expression in single transformation event via transgene stacking in operons and no position effect due to site-specific integration of transgenes by homologous re-combination. Most importantly, chloroplast transgenic plants are eco-friendly because their transgenes are maternally in-heritance in most crop plants. However, chloroplast trans-formation system has limited success in crops alike nuclear transformation. In the past two decades, great progress has been made to overcome the limitations of chloroplast transformation, thus expending chloroplast bioreactor to several important crops including soybean, carrot, lettuce, and oilseed. Therefore, it has become possible that chloro-plast transformation of crops can be used not only for the improvement of agronomic traits, but also for the production of vaccines and high valuable therapeutic proteins in pharmaceutical industry.