Cloning And Transformation Of PtMADS4 And PtMADS5 Genes In Populus Tomentosa Carr

Populus is a widely cultivated species in the world. They are viewed asmodel systems in plant biology. Populus is the third plant species which is sequenced after Arabidopsis and rice. And it is also the first complete sequenced wood species. The sequencing of the Populus genome promises to enrich the biology knowledge of energy sources.The plan shows important practice value.Two MADS-box genes named as PtMADS4 (DQ789398) and PtMADS5 (DQ646480) were isolated from the buds using the PCR-based strategy combined with Race methods. The two genes are highly conformed in MADS domain with other MADS-box genes.They have typical structure of MADS-box genes.Homology tree analysis indicated that PtMADS4 share 78% homology with SEP1 and SEP2. PtMADS5 has 67% homology with Arabidopsis SOC1. According to the phylogenetic analysis, PtMADS5 belongs to the SOC1 subfamily.Downstream 35S promoter, using the expression vector of pBI121 PtMADS5 expression vector was constructed. Near 3' non-coding region, a PCR segment was used to construct antisense expression vector of PtMADS5. On MS + 6-BA 0.25 mg / L + ZT 0.25 mg / L + IAA 0.25 mg / L culture medium, the transgenic plants of PtMADS5 gene were transformed by Agrobacterium and selected from the method of kanamycin. The transgenic plants of PtMADS5 show much dwarf than the wide type, is not blossom in the training period.The shapes of leaves are changed. The shapes of leaves of antisense expression PtMADS5 transgenic plants are also changed. Therefore, the function of transgenic plants of PtMADS5 is various.