Study Develops Herbicide-Resistant Super Basmati Rice Using CRISPR-Cas9

Rice is a staple food for billions of people worldwide, and Basmati rice is a highly prized variety known for its aromatic flavour and long grains. However, like all crops, rice is prone to weeds that compete for nutrients, water, and sunlight. To tackle this problem, Zafar and colleagues have successfully used the gene-editing tool called CRISPR-Cas9 to create a strain of Super Basmati rice that is resistant to a specific herbicide. This exciting development, published in AoB PLANTS, could help farmers save labour and water resources while controlling weed infestations.

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a naturally occurring defence mechanism found in bacteria that helps them fend off viral infections. Scientists have harnessed this system to create a powerful gene-editing tool called CRISPR-Cas9, which allows them to cut and edit DNA in living organisms precisely. This technology has the potential to revolutionize medicine, agriculture, and other fields by enabling targeted modifications to genes.

The researchers in this study used a specific gene editing method called Homology-directed repair (HDR). HDR is a natural process that cells use to repair breaks in their DNA. By combining CRISPR-Cas9 with HDR, scientists can introduce specific changes to an organism’s DNA, such as adding, deleting, or modifying specific genes. This approach allows for precise and targeted gene editing, making it possible to create crops with desirable traits like resistance to diseases, improved nutritional content, or in this case, resistance to a particular herbicide.

The researchers focused on a specific gene called Acetolactate Synthase (OsALS) to achieve herbicide resistance in Super Basmati rice. They introduced a small change in the gene that would make the rice resistant to the herbicide bispyribac-sodium. They then tested different configurations of the CRISPR-Cas9 system to find the most effective way to edit the OsALS gene in Super Basmati rice.

After much experimentation, the team discovered the optimal configuration that allowed the CRISPR-Cas9 system to create precise edits to the OsALS gene in Super Basmati rice, making it resistant to the bispyribac-sodium herbicide. The researchers then tested the herbicide sensitivity of the modified rice, comparing it to other rice varieties. They found that the Super Basmati rice was more resistant to the herbicide than other previously tested Indica rice varieties.

This successful application of the CRISPR-Cas9 and HDR system in Super Basmati rice opens up new possibilities for crop improvement. By using this gene-editing technology, scientists can create crop varieties with better resistance to diseases, pests, or other environmental factors, which could lead to increased crop yields and improved food security.

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Kashaf Zafar, Muhammad Zuhaib Khan, Imran Amin, Zahid Mukhtar, Mehak Zafar, Shahid Mansoor, Employing template-directed CRISPR-based editing of the OsALS gene to create herbicide tolerance in Basmati rice, AoB PLANTS, Volume 15, Issue 2, February 2023, plac059, https://doi.org/10.1093/aobpla/plac059