Scientists Fine-Tune Rice Gene to Fight Sheath Blight

Researchers from India used CRISPR-Cas9 gene editing technology to improve rice resistance to sheath blight. The disease, caused by the fungus Rhizoctonia solani, leads to significant yield losses and remains difficult to manage due to the limited availability of resistant rice varieties. In the study published in Physiological and Molecular Plant Pathology, the research team was able to reduce rice's susceptibility to the disease while maintaining normal growth and yield.

OsSWEET11 is known to act as a susceptibility gene because it helps transport sugars that the pathogen uses to infect the plant. However, completely turning off the gene can harm grain filling and reduce yield. To address this, the research team fine-tuned OsSWEET11 expression in the rice cultivar ASD16 instead of disabling it.

The results revealed that the homozygous promoter-edited mutants showed 20-35% lower disease severity compared to the wild type. Upon R. solani infection, the edited mutants also had up to 60% less fungal biomass and reduced sugar accumulation. The findings demonstrate that targeted promoter editing of OsSWEET11 offers a promising strategy to develop sheath blight-resistant rice without sacrificing plant growth and grain production.

For more information, read the abstract from Physiological and Molecular Plant Pathology.