Promoter replacement by genome editing creates gain-of-function traits in Arabidopsis

We introduced two targeted DNA double-strand breaks on the same Arabidopsis chromosome using CRISPR-Cas9 and replaced the FLOWERING LOCUS T (FT) promoter with that of a histone variant gene through chromosomal inversion. The resulting lines misexpressed FT and flowered early, like FT-overexpressing transgenic plants. This system can be used to create gain-of-function mutations that modify target gene expression as desired without incorporating foreign DNA sequences.