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.