Plants have evolved sophisticated and efficient mechanisms to cope with environmental stress. To balance the response to growth and stress response, plants have an efficient mechanism to turn off the activated stress responses when the stress level is low.

In a previous study, it was revealed that such off-switch mechanism is conferred by Arabidopsis PARAQUAT TOLERANCE 3 (PQT3), when knocked out, resistance to abiotic stress is improved. To verify if rice homolog OsPQT3 is functionally conserved, CRISPR-Cas9 was used to generate three knockout mutants.

Results showed that the OsPQT3 knockout mutants (ospqt3) exhibited improved resistance to oxidative and salt stress. Furthermore, the mutants showed better agronomic performance with improved yield in greenhouse and field conditions, compared with the wild type under salt stress.

Based on the results, PQT3 locus could be a potential for crop improvement with improved stress resistance using gene editing technology.

[www.biorxiv.org]