Study Finds OsRbohB Knockout Increases Rice Heat Tolerance

As climate change drives temperatures higher, heat stress threatens rice crops by disrupting growth, damaging floral organs, decreasing pollen viability, and reducing yields. A study published in the Plant Biotechnology Journal showed that the knockout of the OsRbohB gene successfully reduces reactive oxygen species (ROS) overaccumulation and enhances heat stress tolerance in rice.

ROS are essential for plant growth and stress responses. However, excess ROS under heat stress may disrupt rice development, affecting seedling health, fertility, and grain yield. The enzyme OsRbohB, which drives ROS production, is highly active under heat stress. The researchers used the CRISPR-Cas9 system to generate OsRbohB-knockout (OsRbohB-KO) and OsRbohB-overexpression (OsRbohB-OE) lines to study rice resilience and yield in high-stress conditions.

Compared to the wildtype counterparts, the OsRbohB-KO lines showed a significant increase in chlorophyll contents (5.2%–58.0%), plant growth (48.2%–65.6%) and grain yield (8.9%–20.5%), while reducing HS-induced ROS accumulation in seeds (21.3%–33.0%), seedlings (13.0%–30.4%), anthers (13.1%–20.3%) and grains (9.7%–22.1%), under heat stress conditions. Similarly, grain milling and appearance quality and starch content were observed to significantly increase OsRbohB-KO plants under heat stress conditions during the mature stage.

For more information, read the study from the Plant Biotechnology Journal.