A large family of genes in rice are responsible for the production of small
ubiquitin-like modifiers (SUMOs), which are vital in responding to various
environmental cues. In a previous study, it was demonstrated that the OsOTC
class of SUMO proteases has a critical role in salt and drought stress
through gene silencing or RNA interference. However, finding out the role of
each family member is not possible with RNAi. Thus, Ari Sadanandom from
Durham University and colleagues conducted another study using the
CRISPR-Cas9 system for targeted mutagenesis of OsOTS1 in rice cultivar
Kitaake.

Results showed that guided RNA mediated mutation in OsOTS1 was very
effective with ~95% of the transgenic plants exhibiting the desired effect
without off-target mutations observed. Furthermore, the mutations were
heritable in the subsequent generations. OsOTS1 CRISPR lines showed improved
sensitivity to salt with reduced root and shoot biomass indicating that
OsOTS1 has a major role in salt stress tolerance in rice.

The results imply that precise and effective genome editing can be used to
characterize the SUMO system in rice.

[www.biorxiv.org]