Chloroplast Genome Engineering Techniques and Capabilities – A Review

Chloroplast harbours its own tiny genome and size of the individual genome of chloroplast ranges from 30–200 kb, consisting of nearly 100–250 genes per genome. Although, the concept of chloroplast genome engineering was developed two decades ago, the enormous biotechnological potential of the system has only recently been demonstrated. The advantages of chloroplast genome engineering are multigene engineering through single transformation event, lack of gene silencing and position effect due to homologous recombination, exclusion from pollen transmission due to maternal inheritance and high level of transgene expression. More than 100 transgenes have been stably integrated and expressed in the chloroplast genome, including the genes coding for industrially valuable enzymes, biomaterials, biopharmaceutical proteins, antibodies, antibiotics and vaccine antigens. The important agronomic traits modified in plants are resistance to biotic and abiotic stresses and herbicide tolerance. This review focuses on recent exciting developments in this field.