CRISPR-Cas9 DNA constructs are transformed into cells via
Agrobacterium-mediated transformation. However, this process is associated
with a high possibility of CRISPR-Cas9 DNA constructs being integrated into
the plant genome, causing unwanted genetic changes. Aiming to avoid this,
Zhen Liang of Chinese Academy of Sciences developed a genome editing method
for bread wheat (Triticum aestivum) using CRISPR-Cas9 ribonucleoproteins
(RNPs).

The team successfully generated five mutants from immature wheat embryos.
Analysis reveals that the chance of off-target mutations in wheat cells was
much lower in RNP-mediated genome editing than in editing using DNA. No
off-target mutations were also detected in the mutant plants.

Since no foreign DNA was used in RNP-mediated genome editing, the mutants
obtained were completely transgene free.

[www.nature.com]