Genome Modification through Sequence-Specific Nucleases-mediated Gene Targeting for Crop Improvement

Genome editing techniques allow precise modifications of DNA sequences and offer a great potential for crop improvement. The manipulation of plant genomes relies on the initiation of DNA double-strand breaks by sequence-specific nucleases (SSN) to start DNA repair reactions, either by non-homologous end joining (NHEJ) or homology-directed repair (HDR).

Genome modification through SSNs-mediated HDR for gene targeting enables gene replacement or introduction of precise point mutations, as well as integration of foreign genes at specific locations. The advent of programmable SSNs, such as zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), and the clustered regularly interspaced short palindromic repeat (CRISPR) systems has transformed genome modification in plants in a more controlled manner. However, the potential of gene targeting still has not been well realized for trait improvement in crops, since NHEJ predominates DNA repair process in somatic cells and competes with the HDR pathway. The team of Yongwei Sun from the Chinese Academy of Agricultural Sciences reviewed recent development and applications of precise gene targeting in plants using the three SSN systems.

The team also addressed the challenges and proposed future perspectives to facilitate the realization of precise genome modification through SSNs-mediated gene targeting for crop improvement.

For more on this review, read the full article in Frontiers in Plant Science.