Scientists at the National Institute of Plant Genome Research (NIPGR) in Delhi have successfully utilized CRISPR-Cas9 gene editing technology to enhance phosphate uptake and transport in japonica rice varieties, leading to significant agricultural advancements. These gene-edited rice lines exhibited an increase in yield by 20% under recommended phosphate fertilizer usage. Remarkably, when the phosphate fertilizer supply was reduced to just 10% of the recommended dose, the gene-edited lines still yielded an impressive 40% more than the control group, showcasing their inherent resilience and efficiency in nutrient uptake.
Phosphorus is a crucial mineral for plant growth and development, yet its availability often limits crop productivity. Though phosphate fertilizers are commonly used in farming, previous research indicates that only about 15-20% of these fertilizers are effectively absorbed by plants; the remainder tends to be lost through leaching or runoff. NIPGR’s innovation primarily revolves around enhancing the function of a specific phosphate transporter, OsPHO1;2, which is responsible for moving phosphate from the roots to the shoots of the plants.
In the study, the researchers identified a negative regulator, OsWRKY6, which was found to physically bind to the promoter of the phosphate transporter gene. Initial attempts to knock out this repressor resulted in unexpected outcomes, as the complete knockout negatively impacted other essential functions in the plants. To refine their approach, the researchers strategically removed only the binding site of the repressor from the promoter without eliminating the repressor itself. This precision allowed the gene’s expression to increase while maintaining the functionality of other important plant processes.
When this binding site was deleted, the gene-edited plants demonstrated enhanced phosphate accumulation in the shoots, translating to improved growth and productivity. The increase in phosphate absorption enabled the rice plants to produce more seeds by forming a greater number of panicles, leading to the aforementioned yield enhancements.
This research holds particular significance for regions, like parts of India, where phosphorus deficiency in soil is prevalent. By replicating these gene edits in Indian indica rice varieties, which are more commonly cultivated, the researchers hope to further improve agricultural sustainability and productivity. While there are challenges regarding the adoption of gene-edited crops, including concerns about intellectual property and off-target effects, NIPGR has conducted thorough assessments to ensure precision and safety in their edits. Before any gene-edited seeds are approved for farmer cultivation, substantial checks for off-target alterations and foreign DNA presence are conducted.
Overall, these advancements in japonica rice not only represent a critical scientific achievement but also offer a promising pathway toward sustainable agricultural practices, potentially reducing dependence on phosphate fertilizers and enhancing food security in phosphorus-deprived regions.
-Raja Aditya
