Figure 3.

TAS3 Originated to Regulate ARF Genes in Land Plants.

(A) Conserved motifs in TAS3 transcripts from liverworts. Purple arrows indicate the encoded strand of tasiRNAs; the left-pointing arrow indicates that the functional tasiRNA is located on the antisense strand, and the right-pointing arrow indicates that the tasiRNA is on the sense strand. tasiARF-a1 encoded in liverwort TAS3 genes targets ARF genes with the tasiRNA:target pairing (cleavage site marked with a red arrow) and validating, experimentally derived PARE data shown in the middle T-plot. The red dot in the plot of PARE data marks the cleavage site directed by tasiARF-a1.

(B) Conserved motifs in a few representative TAS3 genes in mosses. Besides tasiARF-a2, previously reported to target ARF genes, another tasiRNA, denoted as tasiARF-a3, was predicted to target ARF genes. The tasiARF-a2 and tasiARF-a3 sequences are encoded in the antisense and sense strands of TAS3 transcripts, respectively.