Review: Plant Genome Editing Targeted by RNA-Guided DNA Endonuclease CRISPR/Cas9

Abstract

This review chronicles the development of the research on CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeat/CRISPR associated protein 9) during the last 30 years from the discovery of CRISPR sequence, of biological significance and of the molecular mechanism for adaptive bacterial immunity. It describes recent works on structural and functional diversity of CRISPR/Cas systems, and on three-dimensional structure-based improvements of on-target specificity of CRISPR/Cas9 and Cpf1 endonucleases. The review ends with the application of CRISPR/Cas9 to targeted editing of plant genomes. Importantly, plant commodities modified by CRISPR-Cas9 have not been considered as genetically modified organisms (GMO) as long as foreign DNAs from plant pests were not introduced, according to the recent determination by the USDA.