Salicornia Choline Plus Single-oxygenase Gene Cloning And Expression In Tobacco

The full length CMO cDNA was cloned from Salicornia europaea by RT-PCR and RLM-RACE. CMO cDNA (1844bp) included a 154bp 5' UTR, a 361bp 3' UTR, a putative polyadenylylation signal and a 1329bp open reading frame encoding a 442-amino-acid polypeptide which was 84%, 79%, 79% and 78% to CMO sequences of Suaeda liaotungensis, A.hortensis, A.tricolor and B. vulgaris in amino acid homology respectively. The deduced amino acid sequence included the conserved mononuclear Fe-binding motif "CTH" and "CPYH" and the conserved Rieske-type iron-sulfur cluster-binding region "HVPYAH". G was considered as the possible transcription initiation site based on the principle of RLM-RACE and the analysis of CMO 5' UTR sequences.The CMO ORF was cloned and the plant expression vector pBI121-CMO was constructed. The resultant plasmids pBI121-CMO was transferred into Agrobacterium tumefaciens (GV3101) by the liquid nitrogen freezing thaw method.The CMO gene was transferred into tobacco (Nictiana tabacum L. cv. 89) via Agrobacterium mediation. PCR analysis showed that the CMO gene was transferred into tobacco. Relative electronic conductivity demonstrated less membrane damage in transgenic plants than in the wild type.