Download state-of-the-art genome engineering in plant biotechnology

STATE-OF-THE-ART GENOME ENGINEERING IN PLANT
BIOTECHNOLOGY
Prof. Dr. Rainer Fischer
Institut für Biologie VII, RWTH Aachen University and Fraunhofer IME,
Forckenbeckstrasse 6, D-52074 Aachen, Germany
The ability to introduce double strand breaks (DSBs) at precise sites in the plant genome
using engineered nucleases allows the generation of targeted mutations in one or more genes,
the insertion of new sequences, and the introduction of more complex genomic
rearrangements. This provides a powerful set of tools that can be exploited in a variety of
applications, from basic research to plant breeding and metabolic engineering. Three types of
site-specific nucleases are commonly used for genome engineering: zinc finger nucleases
(ZFNs), transcription activator-like effector nucleases (TALENs) and most recently the
clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated
protein 9 (Cas9) system. The latter in particular has been rapidly and widely adopted by the
plant research community due to its convenience and versatility. Although different
experimental setups can be difficult to compare, the increasing volume of data on genome
editing allows us to draw some conclusions about the efficiency and characteristics of each
genome editing platform. The simplest form of targeted modification is the gene knockout
achieved when DSBs are erroneously repaired by endogenous non-homologous end-joining
(NHEJ).
It is now easy to achieve such knockouts in most plant species, thus accelerating plant
breeding and allowing the generation of transgene-free plants as this technology is
deregulated in multiple countries. Alternatively, allele replacements and gene knock-in events
can be achieved by providing a repair template that promotes homology-dependent repair
(HDR). As well as creating specific mutations, this allows molecular trait stacking or
metabolic engineering, by the introduction of new genetic material at defined sites. A
nuclease-independent genome editing approach based on oligonucleotide-directed
mutagenesis (ODM) has also been developed and has become an efficient method for the
introduction of precise, single-nucleotide mutations.
This keynote talk provides a comprehensive overview of lastest genome engineering
approaches and achievements in the field of plant biotechnology.