Cloning Of MYB Transcription Factor And Expression Of Anthocyanin Bionsynthesis Genes In Muscari Botryoides

Transcription factors play an important role in regulation of plant growth andphysiological metabolism by regulation of gene expression at the transcription level. MYBtranscription factor gene is one of the largest families in plants. Plant MYBs have beenimplicated in controlling pathways as diverse as secondary metabolism (including theanthocyanin pathway), development, signal transduction and disease resistance. SincePaz-Ares isolated the first MYB transcription factor from plants, a large number of MYBgenes have been isolated and identified. In recent years, many MYB genes have been isolatedfrom apple, gentian and lilium, but the research on MYB gene in Grape Hyacinths is rare. Inthis paper, One novel gene encoding MYB protein was isolated from Grape Hyacinths and thegenes in the anthocyanin biosynthesis pathway were analyzed. The main results of this studyare as follows:1.Part of sequences of MYB transcription factor was determined through The RNA-Seqproject. The full-length sequence of the MYB gene was obtained using RACE method, whichis designated as MaMYB1. Comparison of deduced amino acid sequence showed that it istypical R2R3-MYB transcription factor because of including two conserved MYB domainsnear the N-terminus．2. The expression pattren of the gene in different organs Was studied using realtime-PCR. The results showed that the gene was predominantly expressed in flower tissues.And The expression of MaMYB1in white Grape Hyacinths was higher than that in blue one.3. The recombinant vectors pGBKT7-MaMYB1was constructed and transformed intothe yeast stains AHl09，then the positive yeast transformants were selected using the SD/-Trpselective medium and the SD/-Trp-His-Ade+X-α-gal selective medium．The transcriptionalactivation of MaMYB1protein Was confirmed by the yeast system. The results show thatMaMYB1protein has the transcriptional activation activity. The green fluorescent proteinexpression vector PBI221-MaMYB1was constructed and transformed into the epidermal cellsof onion via bombardmental method．The results of instantaneous expression showed that MaMYB1protein was localized in cell nucleus.4. HPLC analysis of2Muscari perianths revealed that the accumulation of anthocyaninsis rare in white Grape hyacinth, while the main flower pigments in blue Grape hyacinth wereDelphinidin (Del) and Cyanidin (Cy). Moreover, A further study of the main anthocyaninbiosynthesis genes were analyzed by real time-PCR. We suggested that the low expression ofF3′5′H and the high expression of FLS may lead to the anthocyanins especially delphinidinwas difficult to accumulate in white Grape hyacinth.