The CRISPR-Cas9 system has been widely used for modifying endogenous genes.
Thus, it is expected to be applied for the breeding of other economically
important plant species. A research team led by Ayako Okuzaki from Tamagawa
University in Japan recently modified a fatty acid desaturase 2 gene (FAD2),
which encodes an enzyme that catalyzes the desaturation of oleic acid, in
rapeseed (Brassica napus) cultivar, Westar.
Two guide RNAs were designed to target the BnaA.FAD2.a gene and two mature
plants with mutant alleles were generated. Plants with the fad2_Aa allele
without any transgenes were selected from the backcross progenies and plants
homozygous for fad2_Aa were then produced by self-crossing the BC1
progenies. The fatty acid composition analysis of their seeds revealed a
significant increase in the content of oleic acid compared to wild types.
These results showed that the application of the CRISPR-Cas9 system is
useful in producing desirable mutant plants with agronomically suitable
traits by modifying their metabolic pathway.