Characterization of WAP2 gene in Aegilops tauschii and comparison with homoeologous loci in wheat

Publication Type:Journal Article
Year of Publication:2009
Journal:Journal of Systematics and Evolution
Date Published:2009
ISBN Number:1759-6831
Keywords:Aegilops tauschii, AP2 gene, Fringillidae, miniature terminal inverted repeat element (MITE), Q gene, Serinus, Serinus serinus, wheat
Abstract:Abstract  The Q/q gene, also known as WAP2, is an important gene for wheat domestication and is a member of the AP2 (APETALA2) class of transcription factors. In the present study, we first isolated the WtAP2 allele (where the superscript “t” refers to the speciese source, in this case “tauschii”) on chromosome 5D from Aegilops tauschii Coss., the D-genome donor species of common wheat. We found that WtAP2 and the AP2 gene from Arabidopsis share a central core of the AP2 polypeptide, a highly basic 10-amino acid domain, and an AASSGF box, although there are many differences in the 37-amino acid serine-rich acidic domain and the remaining regions. In addition, WtAP2 was highly homologous to the homoeologous loci on 5A and 5B of wheat at both the nucleotide and amino acid level. However, there were some variations that are probably related to gene function. In the first AP2 domain, the amino acids VYL on the 5D and 5A loci were replaced with LLR on 5B. In the 37-amino acid serine-rich acidic domain, WtAP2 on 5D had an extra amino acid insertion. There was also a variation at the 329 amino acid position, which is thought to be related to the appearance of free-threshing wheat. At this position, the amino acid is isoleucine on 5A for the Q allele and valine for the q allele, whereas the amino acid is leucine on 5D and 5B. Furthermore, a Stowaway miniature terminal inverted repeat element (MITE) insertion was present in the ninth intron of WAP2 on 5B of all common wheats and partial tetraploid Triticum turgidum wheats. These results provide new clues for studies into the evolutionary biology of WAP2 and the origin of common wheat.
Short Title:Journal of Systematics and Evolution
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith