The CRISPR-Cas9 system has been widely used as a tool for genome engineering
in various organisms. While some vectors for CRISPR-Cas9 in plants have been
reported, there are still issues on low efficiency.
Hiroki Tsutsui and Tetsuya Higashiyama of Nagoya University in Japan
developed a highly efficient CRISPR-Cas9 vector for Arabidopsis thaliana,
the pKAMA-ITACHI Red (pKIR). The vector harbors the RIBOSOMAL PROTEIN S5 A
(RPS5A) promoter, which drives the Cas9. The RPS5A promoter maintains high
constitutive expression at all developmental stages starting from the egg
cell and including meristematic cells.
Mutations induced by pKIR were carried in the germ cell line of the T1
generation. Further analysis of the T2 plants indicated that pKIR strongly
induced heritable mutations. These results suggest that the pKIR system can
be a powerful molecular tool for genome engineering in Arabidopsis.