# Development of Resistance to Damping-Off in Rice, Oryza sativa L., Using CRISPR/Cas9

## TL;DR

Scientists used CRISPR/Cas9 to edit a gene in rice plants, making them more resistant to damping-off disease, a problem that harms rice seedlings and lowers yields.

## Contribution

The study demonstrates the successful use of CRISPR/Cas9 to enhance damping-off resistance in rice by editing the OsDGTq1 gene.

## Key findings

- CRISPR/Cas9 editing of OsDGTq1 resulted in rice plants with altered resistance to damping-off pathogens.
- Edited rice lines showed distinct disease responses and gene expression changes compared to the original variety.
- The study suggests genome editing can accelerate rice breeding and reduce reliance on chemical treatments.

## Abstract

Damping-off disease hinders rice seedling growth and reduces yield. Current control methods, such as seed or soil sterilization, rely on chemicals that cause environmental pollution and promote pathogen resistance. As a sustainable alternative, we targeted the damping-off resistance-related gene OsDGTq1 using CRISPR/Cas9. Field experiments first verified OsDGTq1’s significance in resistance. The CRISPR/Cas9 system, delivered via Agrobacterium-mediated transformation, was used to edit OsDGTq1 in rice cultivar Ilmi. Lesions from major damping-off pathogens, Rhizoctonia solani and Pythium graminicola, were observed on G0 plants. All 37 regenerated plants contained T-DNA insertions. Among them, edits generated by sgRNA1-1, sgRNA1-2, and sgRNA1-3 resulted in the insertion of two thymine bases as target mutations. Edited lines were assigned names and evaluated for agronomic traits, seed-setting rates, and pathogen responses. Several lines with edited target genes showed distinct disease responses and altered gene expression compared to Ilmi, likely due to CRISPR/Cas9-induced sequence changes. Further studies in subsequent generations are needed to confirm the stability of these edits and their association with resistance. These results confirm that genome editing of OsDGTq1 alters resistance to damping-off. The approach demonstrates that gene-editing technology can accelerate rice breeding, offering an environmentally friendly strategy to develop resistant varieties. Such varieties can reduce chemical inputs, prevent pollution, and minimize seedling loss, ultimately enhancing food self-sufficiency and stabilizing rice supply.