Complex sentence: Several groups have design artificial TAL effectors and demonstrated their ability to target new DNA sequences in a reporter system in plant cells, in a yeast assay, or target and activate endogenous genes in tomato and Arabidopsis thaliana.
Split into simpler sentences: Several groups have design artificial TAL effectors and demonstrated their ability to target new DNA sequences in a reporter system in plant cells or in a yeast assay. A subsequent publication demonstrated that artificial TAL effectors could be used to target and activate endogenous genes in tomato and Arabidopsis thaliana.