Cell-Penetrating Peptides and DNA-Free Genome Editing in Plants

Genome editing technology based on the clustered regularly interspaced short palindromic repeats/Cas system is an important achievement of molecular biology. Nevertheless, public concerns regarding genetically modified organisms and regulatory restrictions have limited the use of this technology. Cell-penetrating peptides (CPPs) are protein transduction domains, usually less than dozens of amino acids, which have the ability to take cargo and penetrate the cell membrane of recipient cells. CPPs have only minor cytotoxicity and are ideal transfection tools for DNA-free transfection and genome editing in plants. In this review, we discuss the classifications and translocation mechanisms of CPPs, as well as the brief history of CPPs mediated DNA-free genome editing.