Cloning of SAMDC gene from Festuca arundinacea Qiancao No. 1 and construction of its plant expression vector

SAMDC gene was amplified from cDNA of Festuca arundinacea Qiancao No. 1 leaves and DNA sequencing analysis indicated that the amplified fragment contained 1 835 nucleotides, which involved a tiny upstream open reading frame(ORF) of 9 bp, a small upstream ORF of 147 bp and a main ORF of 1 185 bp encoding 395 amino acids. There was one overlap base between the tiny upstream ORF and the small upstream ORF. The homology between the cloned fragment and the FaSAMDC gene of Festuca arundinacea registered in GenBank was 95.05% and the homology of their encoded amino acid was 98.22%. This cloned fragment was inserted into modified plant expression vector pCAMBIA1300 with multiple cloning sites using the KpnI and PstI enzyme. The plant expression vector pCAM-SAMDC with genes of SAMDC and hygromycin resistance was obtained by agarose gel detection, restriction enzyme digestion and sequencing which was suitable for monocotyledons genetic transformation. The recombinant plasmid was transmitted into Agrobacterium tumefaciens component cells GV3101 and EHA105 and the positive clone was selected by PCR. These works laid a foundation for further stress tolerance Poaceae grass via Agrobacterium-mediated method.