Strategies for delivery of CRISPR/Cas-mediated genome editing to obtain edited plants directly without transgene integration

Increased understanding of plant genetics and the development powerful easier-to-use gene editing tools over past century have revolutionized humankind’s ability to deliver precise genotypes in crops. Plant transformation techniques are well developed for making transgenic varieties certain crops model organisms, yet reagent delivery regeneration remain key bottlenecks applying technology most Typical protocols produce transgenic, genetically modified (GM) rely on transgenes, chemical selection, tissue culture. make edited (GE) also use even though these may be undesirable final crop product. In some crops, transgenes routinely segregated away during meiosis by performing crosses, thus only a minor concern. other particularly those propagated vegetatively, complex hybrids, or with long generation times, such crosses impractical impossible. This review highlights diverse strategies CRISPR/Cas reagents regenerable cells recover plants without unwanted integration transgenes. Some examples include delivering DNA-free as ribonucleoproteins mRNA, relying expression from non-integrated DNA, using novel mechanisms viruses nanoparticles, unconventional selection methods avoid and/or avoiding culture altogether. These advancing rapidly already enabling scientists precision CRISPR tools.