Allelic Variation and Transcriptional Isoforms of Wheat Gene Regulating Anthocyanin Synthesis in Pericarp.

Recently the gene encoding bHLH transcription factor has been isolated from the bread wheat ( L.) genome and shown to co-locate with the gene conferring purple pericarp color. As a functional evidence of and being the same, higher transcriptional activity of the gene in colored pericarp compared to uncolored one has been demonstrated. In the current study, we present additional strong evidences of to be a synonym of . Furthermore, we have found differences between dominant and recessive () alleles. Light enhancement of transcription was paralleled with increased AP accumulation only in purple-grain wheat. Coexpression of and the maize MYB TF gene induced AP accumulation in the coleoptile of white-grain wheat. Suppression of significantly reduced AP content in purple grains. Two distinct alleles ( and ) were isolated from purple- and white-grained wheat, respectively. A unique, compound -acting regulatory element had six copies in the promoter of , but was present only once in . Analysis of recombinant inbred lines showed that was necessary but not sufficient for AP accumulation in the pericarp tissues. Examination of larger sets of germplasm lines indicated that the evolution of purple pericarp in tetraploid wheat was accompanied by the presence of . Our findings may promote more systematic basic and applied studies of anthocyanins in common wheat and related Triticeae crops.