Cloning And Primary Function Analysis Of Four MADS-box Genes In Populus Tomentosa Carr.

The MADS-box gene family is a transcription factor family which sequences are specific. It is widely existed in human, animal and plants. MADS-box genes play diverse roles in plant development. According to the phylogenetic analysis the MADS-box gene family in Arabidopsis are divided into five groups named Mα, Mβ, Mγ,Mδand MIKC. And the members of MIKC have a typical structure of MADS domain, I domain, k domain and C terminal.Populus is a widely cultivated species in the world. They are viewed as model 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.In order to study the roles of MADS-box genes in poplar development, four MADS-box genes were isolated from cambium materials using the PCR-based strategy combined with RACE methods. These genes are named as PtMADS1,PtMADS2,PtMADS3 and PtMADS5. Sequence analysis demonstrates the four 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 PtMADS1and PtMADS2 share high homology with SVP and AGL12 in Arabidopsis, PtMADS3 share high homology with AGL14 and AGL19 whilePtMADS5 share high homology with SOC1. According to the analysis of phylogenetic tree, PtMADS1gene belong to the STMADS11 subfamily, PtMADS2 belong to the AGL12 subfamily while PtMADS3 and PtMADS5 belong to the SOC1 subfamily.The expression vector of PtMADS1 and PtMADS5gene were constructed and transform them into populus.