Apel & Bock, [42] demonstrated the potential of plastids genome engineering for the nutritional enhancement of food crops when they enhanced carotenoid biosynthesis in transplastomic tomatoes by induced lycopene-to-provitamin A conversion. The transplastomic technology could also be useful for engineering agronomic traits including phytoremediation [78] reversible male sterility [79] , and toler-ance/resistance of stresses such as diseases, drought, insect pests, salinity and freezing that can severely limit plant growth and development [3] .