Chinese researchers have developed a new base editing system to assist in the precise improvement of rice.

Recently, the Crop Precision Breeding Technology Innovation Team of the Crop Science Research Institute of the Chinese Academy of Agricultural Sciences has successfully developed a new base editing system based on the independently developed gene editing tool Cas12i3 in China, and used this system to create a new germplasm of herbicide-resistant rice. Compared to mainstream foreign tools, Cas12i3, as a gene editing tool independently developed in China, has unique advantages such as smaller size and a wider range of applicability for editing. However, the adenine base editor relying on Cas12i3 has not been successfully developed yet, and the cytosine base editor of Cas12i3 has relatively low editing efficiency in plants. Therefore, the development of an efficient base editing system based on Cas12i3 is of great significance for enriching China's breeding technology toolbox. The research team constructed five different versions of base editors and evaluated their editing efficiency systematically. One architecture combining two specific functional units performed the best, significantly improving adenine and cytosine base editing efficiency, and expanding the base editing window. In stable genetically engineered rice plants, the optimized base editing tool can increase the original editing efficiency by 4.78 times and 3.35 times, respectively. Industry experts believe that this research provides important tools and technical support for crop gene function analysis and precise genetic improvement. The relevant research results were recently published in the international academic journal "Chinese Bulletin of Botany."