Genome-wide analysis reveals the evolution and structural features of WRINKLED1 in plants.

WRINKLED1 (WRI1), an AP2/ERE transcription factor, is one of the most important regulators of oil accumulation. It has been extensively studied in angiosperms, but its evolution and overview features in plants remain unknown. In this study, WRI1s, as well as WRI1-likes in non-WRI1 species, were investigated in 64 genome-sequenced plants. Their origin, distribution, duplication, evolution, functional domains, motifs, properties, and cis-elements were analyzed. Results suggest that WRI1 and WRI1-like may originate from Chlorophyta, and WRI1-likes in angiosperms resemble phylogenetically and structurally WRI1s from Chlorophyta and non-vascular plants. WRI1 or WRI1-like may be essential to vascular plants but not to non-vascular plants. Two YRG elements and two RAYD elements, as well as their phosphorylation sites and the 14-3-3 binding motif, are relatively conserved from Chlorophyta to angiosperm. The predicted DNA-binding domains are slightly shorter than the combination of one YRG element and one RAYD element. WRI1 gradually evolves from alkalinity to acidity. More motifs were developed in N-terminuses and C-terminuses in vascular plants. A short acidic amino-acid-enriched domain in the C-terminal region is predicted to be the putative transactivation domain. The VYL exon appears randomly in different WRI1 transcripts and it is not important for the function of WRI1. In addition, more cis-elements developed during WRI1 evolution may suggest its more complicated regulation and physiological functions. These results will assist future function studies of WRI1 and evolution studies of fatty acid biosynthesis regulation in plants.