Abstract
A functionally unknown gene sharing high homology at the amino acid level with mammalian Na+/bile acid transporter (NBT) is widely distributed in plants. Five NBT homologues are found in the Arabidopsis genome, and 4 NBT homologues in rice. One of the subfamilies of the NBT family, NBT1 is extremely conserved among various plants in the amino acid sequence.
We previously reported an existence of an NBT1 homologue in Mesembryanthemum crystallinum (McNBT1). To investigate its role in plant, McNBT1 ORF was fused with 35 S promoter. The construct was transformed into tobacco via Agrobacterium. Although there is little difference in the growth and morphological features between transformants and a wild type, mRNA of McNBT1 was detected in the leaves of transformants by semiquantitative RT-PCR. We are investigating other phenotypes of the transformants, and also constructing a plasmid containing a yeast GAL1 promoter-McNBT1 fusion gene for heterologous expression in yeast cells.
