Abstract
Alkaloids are secondary metabolites with pharmacological activity and many function in the chemical defense of plants against herbivores and pathogens. The major alkaloid of the Nicotiana species, nicotine, is synthesized exclusively in the root , and translocated via xylem transport from the root tissues to the vacuoles of leaves. However, its transport mechanism in plant cells is still largely unknown. Recently, transcriptome analysis of methyl jasmonate-elicited tobacco BY-2 cells identified four transporter genes (Nt-JAT1, C215, T408, T449) which were highly up-regulated in a coordinate manner with the nicotine biosynthetic genes1). In this study, we characterized Nt-T408, which belongs to nucleobase cation symporter-1 (NCS-1) family protein. Nt-T408 was expressed in roots, stems, and leaves, and localized to the plastid of leaf cells. To investigate the substrate of Nt-T408, overexpression and RNAi lines of Nt-T408 in cultured tobacco BY-2 cells were established. The metabolome analyses are now undergoing.
1) Goossens A et al. (2003) PNAS 100: 8595-8600.
