CRISPR/dCas9:TF Mediated Transcriptional Regulation in Plants

Developing targeted genome regulation approaches holds much promise for accelerating trait discovery and development in agricultural biotechnology. The type II CRISPR/Cas system has been adapted for genome editing and transcriptional modulation purposes across a variety of organisms. Here, we employed this system for targeted transcriptional regulation in planta by developing chimeric dCas9-based activators and repressors. By fusing activator and repressor domains to the C-terminus of dCas9, respectively, we generated transcriptional activators: dCas9.EDLL and dCas9.TAD, as well as transcriptional repressor: dCas9.SRDX. Our data demonstrate that the dCas9.EDLL and dCas9.TAD activators, guided by gRNAs complementary to promoter elements, induce strong transcriptional activation on episomal targets in plant cells. Moreover, our data suggest that the dCas9.SRDX repressor and the dCas9.EDLL and dCas9.TAD activators are capable of markedly repressing or activating, respectively, the transcription of an endogenous genomic target. Our data indicate that the CRISPR/dCas9:TFs DNA targeting system can be used in plants as a functional genomic tool and for biotechnological applications.