The Molecular Regulative Functions Of The Populus Trichocarpa Transcription Factor MYB-like1in Synthesis Of Anthocyanins Metabolism

Anthocyanin is a class of secondary metabolites, and it plays an important role in the process of plant growth and development. Its biosynthesis are mainly affected by two kinds of genes, structural genes and regulatory genes(transcription factors). In this study we clone a transcription factor of MYB family from stem of Populus trichocarpa. Based on the domain analysis we find it contains an atypical MYB domain, so we named it PtMYB-likel. We study the function of PtMYB-likel by means of molecular biology and genetics and find that it involves in the regulation of anthocyanin synthesis pathway.The results are as follows:During the expression characteristics analysis in different tissues of Populus trichocarpa by semi-quantitative PCR, we find that its expression levels are relatively high in mature leaves, unmature leaves, lignified stem and developing xylem. Whereas, its expression levels in terminal buds, unlignified stem and phloem enriched fraction is relatively weak, and no expression in root area.By means of genetics, we find that the color of leaves and petioles appeare purple in transgenic plants compared with WT, suggesting that PtMYB-likel gene may be involved in the regulation of anthocyanin biosynthesis metabolism; After the anthocyanin content measurement, we find the anthocyanin content of overexpression plants TP5, TP12, TP13are8times,7times and6times than that of WT respectively. This result confirms PtMYB-likel is involved in anthocyanin biosynthesis metabolism.The structure genes and regulatory genes of anthocyanin synthesis pathway are analyzed in transgenic plants by quantitative PCR, the results show that:most of the structural genes expression levels have differently degree to elevate. Among them, the expression levels of PAL, C4H,4CL, DFR, ANS, FLS3,78D2, GST1, TT19are5-10times as much as the one in the WT; The expression levels of CHS, F3H, F3’H, FLS1,75C1, FGT, BAN, TL2are20times than that of WT, especially in TP5plants. In the regulatory genes, TT2, PAP1, TT8, MYB111, MYB113, MYB11transcription levels have improved significantly, especially in the TP5plants. The transcription level of PAP1is45times than that of WT, and the levels of MYB11, MYB113are25times than that of WT. The transcription levels of PAP2, TT8, TTG1, MYB111, EGL3are not like PAP1so apparently obvious, but the levels improve so much in different extent. This result clearly shows that the PtMYB-likel regulates transcription levels structural genes and regulation genes in anthocyanin synthesis pathway and enhance anthocyanin biosynthesis metabolism.Our study identifies a MYB family transcription factor involved in regulation of anthocyanin synthesis pathway, and it not only provides research materials for further understanding of MYB family transcription factors function, but also offers a very valuable genetic resources for the new varieties of ornamental plant cultivation.