The CRISPR-Cas9 system has been used to develop plants with resistance to
DNA virus infections. However, there is no RNA virus control method in
plants that uses CRISPR-Cas system to target the viral genome directly.

The team of Tong Zhang from South China Agricultural University reprogrammed
the CRISPR-Cas9 system from Francisella novicida to confer molecular
immunity against RNA viruses in Tobacco (Nicotiana benthamiana) and
Arabidopsis plants.

Plants expressing FnCas9 and the sgRNA specific for the cucumber mosaic
virus (CMV) or tobacco mosaic virus (TMV) exhibited significantly less virus
infection symptoms and reduced viral RNA accumulation. Furthermore, in the
transgenic virus-targeting plants, the resistance was inheritable and the
progenies showed significantly less virus accumulation.

These data reveal that the CRISPR-Cas9 system can be used to produce a plant
with stable resistance to RNA viruses, broadening the use of this technology
for virus control in agricultural field.

[onlinelibrary.wiley.com]