CRISPR/Cas-mediated gene targeting in plants: finally a turn for the better for homologous recombination
We summarize recent progress of CRISPR/Cas9-mediated gene targeting in plants, provide recommendations for designing gene-targeting vectors and highlight the potential of new technologies applicable to plants.
Gene targeting (GT) is a tool of urgent need for plant biotechnology and breeding. It is based on homologous recombination that is able to precisely introduce desired modifications within a target locus. However, its low efficiency in higher plants is a major barrier for its application. Using site-specific nucleases, such as the recent CRISPR/Cas system, GT has become applicable in plants, via the induction of double-strand breaks, although still at a too low efficiency for most practical applications in crops. Recently, a variety of promising new improvements regarding the efficiency of GT has been reported by several groups. It turns out that GT can be enhanced by cell-type-specific expression of Cas nucleases, by the use of self-amplified GT-vector DNA or by manipulation of DNA repair pathways. Here, we highlight the most recent progress of GT in plants. Moreover, we provide suggestions on how to use the technology efficiently, based on the mechanisms of DNA repair, and highlight several of the newest GT strategies in yeast or mammals that are potentially applicable to plants. Using the full potential of GT technology will definitely help us pave the way in enhancing crop yields and food safety for an ecologically friendly agriculture.
KeywordsGene targeting Homologous recombination Double-strand break Cas9 Cas12
We apologize to all colleagues in this field, as due to space limitations, we were not able to cite all relevant reports on the rapidly growing aspects of genome engineering. We are thankful for the funding support from the Ministry of Science and Technology of Taiwan, ROC (MOST 106-2917-I-564-007-A1) and the Bundesministerium für Forschung und Technologie (100334243 SophGenTom). We also acknowledge Amy Whitbread for English editing.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest.
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