The 30th International Conference on Arabidopsis Research (ICAR 2019)

438 / 2019-01-31 10:34:53

Manipulation of plant gene activity through Cas9-derived transcription activator and base editor

CRISPR/Cas9,Gene activation,Transcriptional activation,Gene inactivation,Base editing,mRNA mis-splicing

Plenary track > Omics& New Technology

Both gene activation and inactivation tools are highly desirable for basic and applied plant research. Here, we repurpose the CRISPR/Cas9 technology from a genome editing technology to a targeted transcriptional activation system. Using plant protoplast-based screens, we identified a potent synthetic transcription activator containing the nuclease dead Cas9 (dCas9) and a chimeric transcriptional activation module composed of several transcriptional activation domains, each in multiple copies. This improved synthetic transcription activator allows efficient activation of target gene expression using only a single sgRNA in transgenic Arabidopsis and rice plants. This strategy promises multiplex up-regulation of target gene expression in plants to rewire regulatory networks. Meanwhile, we leverage the Cas9-derived cytosine base editor to introduce precise C-to-T mutations to disrupt the conserved AG/GT intron splice sites in target genes, thereby inducing mRNA mis-splicing and target gene inactivation. This strategy expands the applications of base editing technologies in eukaryotes by opening up a new avenue for gene inactivation.