Plastid transformation transgene containment

In conclusion, plastid-based expression systems provide for potentially higher expression levels than the majority of nuclear expression systems, and with a higher level of transgene containment, but the platform provides limited post-translational processing choices. Also, despite reports of successful plastid transformation of new species beyond Nicotiana, the choice of production host is stiU predominantly restricted to the Nicotiana family. However, this hmita-tion does not present a serious drawback for production of pharmaceutical proteins (except perhaps for edible vaccines ) since tobacco is a non-feed/non-food crop with a weU-estabhshed agriculture. 

---