Many genome editing tools have been developed and new ones are anticipated; some have been extensively applied in plant genetics, biotechnology and breeding, especially the CRISPR/Cas9 system. These technologies have opened up a new era for crop improvement due to their precise editing of user-specified sequences related to agronomic traits. In this review, we will focus on an update of recent developments in the methodologies of editing reagent delivery, and consider the pros and cons of current delivery systems. Finally, we will reflect on possible future directions.
Keywords: Agrobacterium-mediated transformation; DNA; RNA; RNP and virus delivery; biolistic method; genome editing; protoplast transfection; ttransgene-free genome edited plant.