Strategies to improve genome editing efficiency in crop plants

Genome editing technology comprises site-directed mutagenesis of genomes, involving alterations of few bases to precise replacement of a fragment or an entire gene sequence. Among multiple types of genome editing technologies developed, CRISPR-Cas9 and its latest variants have been revolutionizing the field of genetic engineering and plant biotechnology. Despite several advantages the CRISPR-Cas9 technology offers, it often suffers from low efficiency in creating desirable mutants in several crop plant species. In this review, we discuss various emerging strategies to improve genome editing efficiency in crop plants. The strategies include increased expression of genome editing components using high efficiency viral vectors, employment of inhibitors of chromatin modifiers, and using plant DNA viruses as donor DNA carriers. Additionally, we also discuss strategies to obtain transgene-free genome edited crops.