Molecular Cloning And Functional Analysis Of BoEMF2 Gene In Bambusa Oldhami

EMF2(EMBRYONIC FLOWERING 2) plays an important role in maintaining vegetative growth , and the identification of EMF2 is important to the research of flowering mechanismn in bamboo,a group of perennial evergreens with unpredictable, long-periodic, gregarious, and uncontrollable flowering time. A degenerate primer pair has been designed,accroding to the conserved region of OsEMF2,ZmEMF2,and TaEMF2 nucleotide sequences,and DNA fragment of about 450bp has been gained. RACE (Rapid amplification of cDNA ends) procedure was employed for gaining full length cDNA sequence of EMF2 . BoEMF2, the orthologous of EMF2 in Bambusa oldhami, was isolated . The predicted BoEMF2 CDS(Coding Sequence) is 1891bp in length and encodes a protein with 630 amino acid residues,with a region characterized by an acidic cluster and a tryptophan/methionine-rich sequnce named acidic-W/M domain and a single C2H2 zinc finger motif. BoEMF2 protein shows 97,85,55 and 49% identity with it's orthologous in Dendrocalamus latiflorus,Oryza sativa, Vitis vinifera and Arabidopsis thalizna,respectively, suggesting EMF2 is highly conserved in plants. GenomeWalking technology was employed to obtaining promoter,and about 2-kb genomic DNA sequence upstream of 5'UTR has been found.and canonical CAAT-BOX, TATA-BOX and core promoter region have been predicted. RT-PCR analysis shows that transcripts of BoEMF2 in vegetative shoots is about 3.4 fold greater than in folwer buds,and 35S::BoEMF2 Arabidopsis plants display late-flowering phenotypes. These suggest that BoEMF2 participates in maintaining vegetative growth and repressing flowering.