Abstract:

Sucrose transporter is a functional protein which plays an important role in transporting sucrose and sensing specific sucrose signals. A sucrose transporter gene, named as BoSUT2 (GenBank accession number: EU247931), has been isolated from the first strand of Bambusa oldhamii cDNA through RT-PCR method. The cDNA is 1 668 bp long and contains an open reading frame which encodes a polypeptide of 555 amino acids. The result of a homology analysis shows that the deduced BoSUT2 is highly homologous to other SUT proteins from various monocotyledonous species. The similarity with BoSUT1 from B. oldhamii is the highest, reaching to 92.3%. Secondary structure prediction analysis shows that BoSUT2 has trans-membrane domains and sucrose transporter conserved domains, which indicates that BoSUT2 belongs to membrane proteins. BoSUT2 is expressed highly in leaf and sheath, and weakly in root as shown in tissue specific expression tests. BoSUT2 gene is constructed in the GFP fusion expression vector under the control of CaMV 35S promoter; and then transferred into tobacco suspension cells. The results of subcellular localization analysis further demonstrate that BoSUT2 proteins are mainly positioned on the cytoplasmic membrane.

Key words: Bambusa oldhamii, sucrose transporter gene, tissue specific expression, subcellular localization