Research Projects

Rice (Oryza sativa L.) cultivation poses a significant concern in regions with arsenic-contaminated soils and groundwater, such as Punjab, Uttar Pradesh, and West Bengal. In these areas, rice plants tend to accumulate high levels of arsenic, a toxic and carcinogenic element that can cause serious health risks to consumers. In rice, OsNIP2-1 (OsLsi1), a member of the aquaporin (AQP) family, plays a main role in arsenic uptake and translocation. Meanwhile, OsNIP2-1 also acts as a potential silicon influx transporter, which helps in the uptake of silicon in the form of silicic acid from the soil, which is very beneficial for plant growth, mechanical support, stress tolerance, and productivity. Therefore, silicon uptake confers beneficial agronomic traits, and arsenic accumulation poses serious human health risks. Previous studies have shown that complete knockout or knockdown of OsNIP2;1 through mutagenesis or genome editing approaches can drastically reduce arsenic uptake. However, such strategies are not agronomically viable, as OsNIP2;1 is also critical for silicon and boron uptake. This proposal is shaped to develop a rice variety with selective uptake capacity by retaining efficient silicon uptake while minimizing arsenic accumulation. The mentor’s laboratory has previously identified key amino acid residues within the OsNIP2;1 pore region that distinctly influence the permeability to silicon and arsenic (Sharma et al., 2024). Through molecular dynamic simulations and functional analyses, three specific mutations like S207G, S207N, and Q84N have been characterized that can disrupt arsenic transport without impairing silicon uptake. These residues are present in specific locations (S207G and S207N at aromatic/arginine selectivity filter in Helix 5 and G84N at Helix 2 near pore entrance), which determine the solute specificity of the transporter. Building on this foundational research, we aim to introduce targeted mutations in the OsNIP2-1 gene using prime editing, an advanced CRISPR-based genome editing technology. This will ultimately aid in engineering rice lines with reduced arsenic accumulation and maintain efficient silicon uptake, thereby enhancing food safety standards, mitigating health hazards, and enhancing crop productivity in regions grappling with metalloid contamination issues.