Gene Editing Elucidates a Vital Defense Switch in Rice

Scientists from Tamil Nadu Agricultural University used CRISPR-Cas9 to investigate a vital gene in rice called OsNH2 and understand the plant's defense mechanism in fighting diseases. Their findings are available in BioRXiv.

The study found that rice plants where the OsNH2 gene was essentially broken or removed became dramatically more vulnerable to two major threats: sheath blight (a fungal infection) and bacterial leaf blight (BLB). This discovery immediately established the OsNH2 as a vital gene in the plant's overall health and resistance.

The researchers found that OsNH2 works with two related genes, OsNH1 and OsNH3, to build a strong, comprehensive defense against multiple types of agricultural pathogens. The reason for the increased vulnerability lies in how the OsNH2 gene controls the rice plant's internal defense chemistry. When OsNH2 was disrupted, the plant's natural levels of salicylic acid dropped significantly. This sudden decrease led to a series of reactions, such as switching off many key protective genes and factors responsible for fighting infection. When the scientists manually treated the weakened plants by adding back salicylic acid, their resistance was partially restored, proving the role of OsNH2 in sustaining high levels of salicylic acid to maintain defense and protection from the disease.

The findings provide a promising new target for breeding stronger, naturally resistant rice varieties.

Find out more from BioRXiv.