RICE GENOME EDITING USING CRISPR/Cas SYSTEM
Genome editing using the CRISPR/Cas system is a breakthrough tech­nology in plant genetics and breeding. The most large-scale application of this new technology on crop species is observed for rice. This fact is explained not only by the significance of this crop, but also by the relatively high transformation amenability. Although the end result of genome editing is a non-transgenic plant with desired mutation (muta­tions), an unavoidable step in the process of creating such a new mutant is the use of genetic engineering methods. To date, the CRISPR/Cas sys­tem has been tested on dozens of rice target genes, of which mutations in more than 30 genes have led to the desired improvement of economically important traits. The remaining experiments are related mainly to the verification of the genes' functions, and belong to the field of reverse genetics. Improvement or acquisition of new properties is associated with mutations in the genes that affect productivity, grain fragrance and chemical composition, flowering time, the resistance to biotic and abiotic stress factors, and herbicides, as well as pollination control needed in hybrid breeding. These achievements are reviewed in the current article. It is important to note that about fifty different genotypes are already involved in improving rice varieties with the help of genome editing. This creates the prerequisites for a wide practical application of genome editing technologies in rice breeding programs.