Enhancing plant genome editing through the use of a flexible CRISPR-Combo system

Plant genome engineering has greatly benefited from the use of CRISPR-Cas9, its derived base editors, and CRISPR activation systems. However, since these systems are typically used independently, their combined potential is largely unrealized. We create a flexible CRISPR-Combo platform for simultaneous genome editing (targeted mutagenesis or base editing) and gene activation in plants here, based on a single Cas9 protein. We highlight the effective CRISPR-Combo applications for enhancing plant genome editing. By activating the florigen gene in Arabidopsis, CRISPR-Combo is used to shorten the plant life cycle and reduce the effort required to screen transgene-free genome-edited plants. We then use the activation of morphogenic genes in poplar to show how genome-edited plants can regenerate and reproduce more quickly. Additionally, we use CRISPR-Combo, which is recognized as a new technique to primarily enrich heritable targeted mutations, to achieve rice regeneration without the use of exogenous plant hormones. As a versatile tool for genome engineering, CRISPR-Combo has potential uses in crop breeding.