[New strategy for increasing the specific and efficient expression of transgene in plastids].

Plastid gene engineering has become a new way for plant genetic improvements, particularly showing a unique application value in the use of plants as reactors to produce biopharmaceuticals and other important organic compounds. However, plastids only have a semi-autonomous transcription and translation machinery. The transcription of endogenous plastid genes is largely dependent on nuclear-encoded transcription factors. Regulation of foreign gene expression in plastids is influenced by various factors. Several technique strategies for regulation of transgene expression in plastids were reported recently, such as hybrid transcription factor-mediated system, phage T7-based transcription system and bacterial lac suppressor-based system. The application and improvement of these systems will greatly enhance the specific and effective expression of the transgenes, and achieve high-level accumulations of foreign proteins in plastids.