The CRISPR-Cas system for plant genome editing: advances and opportunities

Abstract

Genome editing is an approach in which a specific target DNA sequence of the genome is altered by adding, removing, or replacing DNA bases. Artificially engineered hybrid enzymes, zinc-finger nucleases (ZFNs), and transcription activator-like effector nucleases (TALENs), and the CRISPR (clustered regularly interspaced short palindromic repeats)–Cas (CRISPR-associated protein) system are being used for genome editing in various organisms including plants. The CRISPR–Cas system has been developed most recently and seems to be more efficient and less time-consuming compared with ZFNs or TALENs. This system employs an RNA-guided nuclease, Cas9, to induce double-strand breaks. The Cas9-mediated breaks are repaired by cellular DNA repair mechanisms and mediate gene/genome modifications. Here, we provide a detailed overview of the CRISPR–Cas system and its adoption in different organisms, especially plants, for various applications. Important considerations and future opportunities for deployment of the CRISPR–Cas system in plants for numerous applications are also discussed. Recent investigations have revealed the implications of the CRISPR–Cas system as a promising tool for targeted genetic modifications in plants. This technology is likely to be more commonly adopted in plant functional genomics studies and crop improvement in the near future.