CRISPR-Cas technology has made it easy to knock out genes and study their function in a wide variety of plant species. However, making specific, predictable substitutions in the DNA is still challenging. Most plant species are notoriously bad at homology-directed repair, and prime editing efficiencies are often low. Base editing is an interesting, more efficient alternative to these approaches.
We currently focus on improving Cas12a-mediated base editing. Previously, we optimized adenine base editing in wheat and maize by identifying the most efficient promoters, nuclear localization signals, and gRNA expression system. Now, we zoom in on Cas12a itself. Using large scale synthetic biology and directed evolution we design, construct, and test the performance of tens of thousands of Cas12a variants. The availability of highly efficient base editors will open up opportunities for the engineering of proteins and cis-regulatory elements, or even in planta directed evolution.
