Functional Study Of Transcription Factor MaHY5 In The Anthocyanin Synthesis Pathway Of Grape Hyacinth (Muscari Armeniacum)

Grape hyacinth(Muscari armeniacum)is a kind of ground cover flower which are commonly used because of its beautiful blue flower.As one of the most important environmental factors for plant growth,light has affected the coloration of grape hyacinth in many ways.Studying the coloration mechanism of grape hyacinth is the most important task of flower color breeding.At present,the flower color research of grape hyacinth has been initially identified,and the key structural genes on the anthocyanin synthesis pathway have been cloned and analyzed,and the transcription regulation mechanism has been preliminary clarification.But the influence of light on grape hyacinth’s coloration is still unclear.Based on the previous research,this study screened an important bZIP transcription factor gene in the light response process of grape hyacinth coloration.The main results were as follows:1.A bZIP transcription factor gene have been cloned from grape hyacinth(Muscari armeniacum)which was named MaHY5 and its GenBank accession number is MK281355.It contains a 438 bp ORF that encodes a protein of 145 amino acid.The MaHY5 protein contains an bZIP domain which is highly conserved in evolution process.MaHY5 protein was not predicted to have an N-terminal signal peptide or a transmembrane domain and it was predicated to be a hydrophilic protein that is localized to the nucleus.And transactivation assay showed that it cannot possess transcriptional activity in yeast.2.The qRT-PCR analysis showed that MaHY5 was expressed in various tissues and flower development stages of grape hyacinth,and the expression trend is flower>leaf>bulb>root.The expression was high in flower,and the trend of increasing first and then decreasing in the different periods of flower development.The expression of MaHY5 significantly increased during the period of full coloration of the flower and reached its maximum during the period when the flower was completely open,then the expression suddenly decreased when the flower decayed.The qRT-PCR and HPLC result indicated that the expression of MaHY5 was general correlated with the mode of anthocyanin accumulation.They were both high in petals which are fully opened.Thus,MaHY5 may play a role in the process of anthocyanins accumulation in grape hyacinth.3.Our team have obtained the grape hyacinth MaMybA gene and initially verified its important regulation function in the anthocyanin synthesis pathway,and we have cloned the promoter of MaMybA gene.By constructing the vector and transiently transforming the tobacco,MaHY5 can interact with the MaMybA promoter.It is further proved that the MaHY5 gene may participate in the accumulation process of grape hyacinth flower pigment by regulating the transcription of MaMybA gene.