Applications of Genome Editing Techniques for the Improvement of Medicinal Plants

Abstract

Globally, medicinal plants play an indispensable role in curative as well as preventive medical therapy. The medicinal properties of plants are mainly due to the secondary metabolites, which are the principal bioactive compounds used in therapeutics. These phytoconstituents also form the basis for the use of these plants in traditional herbal medicines. Nonetheless, secondary metabolites production by plant cell culture has several limitations. An increase in yield of these secondary metabolites can be achieved by plant breeding using conventional methods and also genetic engineering-mediated approach. The introduction of next-generation sequencing techniques has shown immense potential in analyzing and identifying the relevant genes/enzymes of the biosynthetic pathways for secondary metabolites production. The advent of targeted genome editing techniques has emerged as an excellent tool for manipulation of genes of biosynthetic pathways to enhance secondary metabolite production. In the recent past, genome editing techniques like meganucleases, ODM (Oligonucleotide-directed mutagenesis), ZFNs (Zinc finger nucleases), TALENs (transcription activator-like effector nucleases) and CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats) have been widely used for genome modifications. For medicinal plants, particularly CRISPR/Cas9 technique has proved to be a valuable method for modifying metabolic pathways and developing plants with optimized secondary metabolite profiles. The present chapter focuses on different genome editing methods, their comparisons and application strategies with highlights on the recent examples of improved medicinal plants obtained by using these tools. Further, the involvement of regulatory measures and future perspectives of genome editing tools for improvement of medicinal plants are also discussed.