Submitted to: Molecular Phylogenetics and Evolution
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/19/2007
Publication Date: 6/30/2007
Citation: Borrone, J.W., Meerow, A.W., Kuhn, D.N., Whitlock, B.A., Schnell Ii, R.J. 2007. The potential of the WRKY gene family for phylogenetic reconstruction: an example from the Malvaceae. Molecular Phylogenetics and Evolution. 44:1141-1154. Interpretive Summary: The WRKY gene family, found only in plants, is an ancient group of genes important in a number of regulatory functions of plant metabolism and development. All WRKY genes contain one or two highly conserved coding regions interrupted by a non-coding region of variable length. We tested the usefulness of five independent WRKY genes for inferring the relationships of plant species, using the closely related genera Herrania and Theobroma of the mallow family. Overall, the combined WRKY DNA sequence matrices performed as well or better than other genes in resolving the relationships of Herrania and Theobroma. The ease of osolating numerous, independent WRKY loci from diverse plant species makes them extremely useful tools for generating multiple, single- or low-copy nuclear loci for molecular studies of plant relationships.
Technical Abstract: The WRKY gene family of transcription factors is involved in several diverse pathways and includes components of plant-specific, ancient regulatory networks. WRKY genes contain one or two highly conserved DNA binding domains interrupted by an intron. We used partial sequences of five independent WRKY loci to assess their potential for phylogeny reconstruction. Loci were originally isolated from Theobroma cacao by PCR with a single pair of degenerate primers; loci-specific primers were subsequently designed. We tested those loci across the sister genera Herrania and Theobroma, with Guazuma ulmifolia as the outgroup. Overall, the combined WRKY matrices performed as well or better than other genes in resolving the intrageneric phylogeny of Herrania and Theobroma as measured by bootstrap values. The ease of isolating numerous, independent WRKY loci from diverse plant species, with a single pair of degenerate primers designed to the highly conserved WRKY domain, renders them extremely useful tools for generating multiple, single- or low-copy nuclear loci for molecular phylogenetic studies at lower taxonomic levels.