CRISPR/Cas9 targeted mutations of OsDSG1 gene enhanced salt tolerance in rice.

ABSTRACT

Salinization is one of the leading causes of arable land shrinkage and rice yield decline, recently. Therefore, developing and utilizing salt-tolerant rice varieties have been seen as a crucial and urgent strategy to reduce the effects of saline intrusion and protect food security worldwide. In the current study, the CRISPR/Cas9 system was utilized to induce targeted mutations in the coding sequence of the OsDSG1, a gene involved in the ubiquitination pathway and the regulation of biochemical reactions in rice. The CRISPR/Cas9-induced mutations of the OsDSG1 were generated in a local rice cultivar and the mutant inheritance was validated at different generations. The OsDSG1 mutant lines showed an enhancement in salt tolerance compared to wild type plants at both germination and seedling stages indicated by increases in plant height, root length, and total fresh weight as well as the total chlorophyll and relative water contents under the salt stress condition. In addition, lower proline and MDA contents were observed in mutant rice as compared to wild type plants in the presence of salt stress. Importantly, no effect on seed germination and plant growth parameters was recorded in the CRISRP/Cas9-induced mutant rice under the normal condition. This study again indicates the involvement of the OsDSG1 gene in the salt resistant mechanism in rice and provides a potential strategy to enhance the tolerance of local rice varieties to the salt stress.