Fig. 2 From:A modular cloning toolkit for genome editing in plants Assembly of level 1 sgRNA expression modules to be used with respective Cas9 nucleases. During the first step (a) annealed complementary oligos encoding the guide are inserted into a level 0 acceptor with the sgRNA backbone using BpiI. During the second step (b), sgRNA is fused with the respective Pol III promoter using BsaI Back to article page