Background
Most current
Conclusions
For a fraction of resources used in the type IIS restriction enzyme-based cloning method and in vitro screening assays, the system reported here allows efficient construction and testing several ready-to-transfect gRNA constructs in < 3 days. In addition, this system is highly versatile and flexible, and by designing only two additional target-specific primers, multiple gRNAs can be easily assembled in any plasmid in a single reaction.
Results
To improve efficiency of cloning multiple guide RNAs for the CRISPR/Cas9 system, we developed a restriction enzyme- and ligation-independent strategy for cloning gRNAs directly in plant expression vectors in one step. Our method relies on a negative selection marker and seamless cloning for combining multiple gRNAs directly in a plant expression vector in one reaction. In addition, using the Agrobacterium-mediated transient assays, this method provides a simple in planta procedure for assaying the effectiveness of multiple gRNAs very rapidly. Conclusions: For a fraction of resources used in the type IIS restriction enzyme-based cloning method and in vitro screening assays, the system reported here allows efficient construction and testing several ready-to-transfect gRNA constructs in < 3 days. In addition, this system is highly versatile and flexible, and by designing only two additional target-specific primers, multiple gRNAs can be easily assembled in any plasmid in a single reaction.