Indigenous Genome-Edited Crop Breeding: TnpB Technology
In a significant advancement for indigenous genome-edited (GE) crop breeding, Indian scientists have developed a new technology using Transposon-associated proteins, known as TnpB. This development offers an alternative to the widely used CRISPR-Cas proteins, providing a cost-effective and compact option for genome editing in plants.
Technology Overview
- Development: Led by ICAR's Central Rice Research Institute (CRRI) in Odisha.
- Functionality: Similar to CRISPR-Cas, TnpB acts as "molecular scissors" for precise DNA editing at target sites.
- Compactness: TnpB proteins are smaller, with 400-500 amino acids compared to 1,000-1,400 in Cas9 and 1,300 in Cas12a, facilitating easier cellular delivery.
- Delivery: Smaller size allows for direct injection into cells without tissue culture, using viral vectors.
Comparison with CRISPR-Cas
- CRISPR-Cas: Controlled by the Broad Institute and Corteva Agriscience, with potential IP constraints.
- TnpB Technology: Eliminates dependency on international IP, allowing free use in research and breeding.
Applications in Rice Varieties
- GE Rice Varieties: Developed using CRISPR-Cas, but face IP challenges for commercial use.
- Specific Edits:
- CRISPR-Cas12a used to enhance yield in Samba Mahsuri rice by editing the 'cytokinin oxidase 2' gene.
- CRISPR-Cas9 used in MTU-1010 rice to improve drought and salinity tolerance by editing the 'DST' gene.
- IP Rights: Negotiations ongoing with Corteva and Broad Institute for license fee waivers for small farmers.
Patent and Future Prospects
- Patent Status: Indian patent granted on September 15, 2025. An international patent application is filed.
- Adoption Challenge: Successful adoption by biotechnologists and breeders is crucial for the technology's impact.
The new TnpB protein-based genome editing system provides a promising tool for Indian agricultural research and crop breeding, potentially overcoming international patent barriers and advancing GE technology in a more accessible and sustainable manner.