CRISPR-Cas9 editing of agricultural crops and medicinal plants: toward a cornucopia of natural products

Plants have been a part of human health since our very beginnings, and many of our modern pharmaceuticals claim their origins from medicinal plants. The range of specialized metabolites synthesized by plants is highly diverse, and metabolic functions have developed over the millennia to cover roles such as defense, adaptation to environmental stress, and even reproduction. These metabolites subsequently play roles in human health and diseases that are both significant and profound. The importance of plant natural products for the pharmaceutical, cosmetic and nutraceutical industries cannot be overstated. However, the fact that these specialized metabolites may be available only in low quantities from plants that are slow growing, endangered, or from fragile environments due to certain biotic and abiotic stresses makes their commercial use challenging despite the scenario that some stresses can enhance the production of secondary metabolites. Genome editing is a technique or technology that comprises of tools like CRISPR/Cas9, TALEN, ZFN. The following review describes the successful use of CRISPR/Cas9 genome editing in engineering medicinal plants, food crops and commercial crops to modulate metabolic pathways involved in the biosynthesis of valuable compounds to improve natural product identification, development and ultimately, commercial viability.