Cloning And Sequence Analyses Of Constan (co) And Leafy (lfy) Homologous Gene Of Dendrocalamus Xishuangbannaensis

The majority bamboos have a long flowering period which is usually 3 to 120 years. Most of them were flowering, and then death. So far, however, the causes and control mechanism of bamboo flowering are still unclear. Althoug there are many hypotheses about the reasons, no one could be verified. So, it becomes a difficult problem in the flowering plant physiology. CONSTANS (CO) is one of the most key genes controlling flowering time of the flowering plants in Photoperiod Pathways. It can directly activate the flowering integrate factor FT and SOC1 to express, and determines whether the plant does feel the changes of the sunshine length. It is the shift regulation and induction gene of flowering plants from vegetative growth to reproductive growth. The flowering plant and the non flowering plant both have the LFY gene. It is an essential gene to form the flower meristem, and also plays a key role in connecting the output signals from series of flower induction pathways and activating the floral organ-determining gene ABC during flower formation. Therefore, the function and mechanism of CO and LFY gene gradually became a hot spot about the flowering genes in recent years.Dendrocalamus xishuangbannaensis D. Z. Li & H. Q. Yang is one new kind of the large-scale tufted bamboos, which is a versatile and economic timber specie, only in southern of Yunnan Province. Fortunately, my teacher picked the precious material during the collection process. In this study, we extracted genomic DNA from the young leaves and RNA from the not flowering spikelets of Dendrocalamus xishuangbannaensis, and then cloned the CO and LFY homologous gene with PCR by self-designed primers. We blasted the DNA sequence and predicted its amino acid sequence in the internet. Preliminary results are as follows:1. There was a CO-like gene of Dendrocalamus xishuangbannaensis to be cloned.(1) According to the analysis of other similar plants'CO gene sequences, one 1901bp DNA fragment was amplified by self-designed primers and cloned into pGEM-T vector. The sequencing and sequence analysis result revealed that this fragmen named as DxCO1 might was the full length sequence of CO homologous gene. It contains two exons which were 759bp and 372bp. The 1119bp coding region was encoded to 373 amino acids. The GenBank registration number is GQ358925.(2) In GenBank, the homology search results that the nucleotide sequence of DxCO1 has high homology of 78% to 91% with other grasses. It guessed that there were a similar zinc finger protein B-box (Cx2Cx8Cx7Cx2Cx4Hx8H) domain at the deduced N-terminal of protein sequences by DxCO1 and a CCT (CO, CO-like, TOC1) domain at the deduced carboxy-terminal.(3) The phylogenetic analysis of the deduced protein sequences with other seed plants CO homologous protein sequences revealed that, DxCO1 clustered into a strongly supported branch with other 6 genes.The sequence and the highly homologous structure of DxCO indicate that DxCO1 is truly one CO-like genes of Dendrocalamus xishuangbannaensis, which may have an important role in regulating its flowering.2. Based on the model plants'LFY gene sequences and the self-designed primers, two 600-900bp length cDNA fragments were cloned from the total RNA by PCR. They were named L1 and L2. After cloning and sequencing, the retrieval and comparative analysis of the structure in GenBank showed that L1 and L2 may were not the LFY homologous gene, which may be due to primer specificity was not high and the template was not fine.