Occurrence of radiocesium in food has raised health concerns after nuclear
accidents. Despite being present at low concentrations in contaminated
soils, cesium (Cs+) can still be taken up by crops and transported to their
edible parts. Such a plant capacity to take up Cs+ from low concentrations
has affected the production of rice (Oryza sativa L.) in Japan after the
nuclear accident at Fukushima in 2011.

Manuel Nieves-Cordones from CEBAS-CSIC, together wuith researchers from
various universities and institutions worldwide, recently reported the
inactivation of the Cs+-permeable K+ transporter, OsHAK1, using the
CRISPR-Cas system, which then reduced Cs+ uptake by rice plants.

In rice, Cs+ uptake is dependent on two functional properties of OsHAK1: a
poor capacity of the plant system to discriminate between Cs+ and potassium
(K+), and a high capacity to transport Cs+ from very low external
concentrations. In an experiment with a Fukushima soil highly contaminated
with 137Cs+, transformed rice plants lacking OsHAK1 function displayed
significantly reduced levels of 137Cs+ in roots and shoots.

These results open new perspectives to produce safe food in regions
contaminated by nuclear accidents.

[onlinelibrary.wiley.com]