Isolation and characterization of genes encoding Myb transcription factor in wheat (Triticum aestivem L.)

Plant Myb transcription factor (TF) is crucial in regulating secondary metabolism, cellular morphogenesis and responses to hormone and stress signals. In this study, 23 Myb gene fragments and 6 nearly complete ORF encoding putative wheat Myb TFs (TaMyb1 to TaMyb6) were isolated. Genomic sequences of three putative TaMyb genes were obtained and it was found that introns were present in TaMyb4 but not in TaMyb1 and TaMyb6. Sequence analysis indicated that these putative wheat Myb TFs all represent typical R2R3Myb. Expression analysis of the six TaMyb genes indicated that they were expressed in root, sheath and leaf, but at different abundance. All members, except TaMyb5, were expressed in developing seed of 2 days after pollination (DAP) with different level. During 2-8 DAP, expression of TaMyb1 and TaMyb2 decreased, TaMyb6 increased, while no change was found for TaMyb3 and TaMyb4, respectively. Expression of TaMyb3 decreased dramatically after GA3 treatment for 8 h. After treated with 30% PEG solution for 8 h, expression of TaMyb2, TaMyb4 and TaMyb5 increased and TaMyb1 declined. It was also noted that TaMyb genes were differentially expressed between wheat hybrids F1 and its parents in roots, stems and leaves. In vivo subcellular targeting experiment in onion epidermal cells indicated that TaMyb1 was localized in the nucleus.