Abstract
Alkaloids play a key role in the plants' defense mechanism against pathogens and herbivores. The major alkaloid of the Nicotiana species, nicotine, is translocated via xylem transport from the root tissues where it is biosynthesized to the accumulation sites, the vacuoles of leaves. However, its transport mechanism 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 genes. Furthermore, Nt-JAT1, MATE transporter, was suggested to be involved in the vacuolar accumulation of nicotine in tobacco leaves.1) In this study, we characterized Nt-C215, which also belongs to MATE family protein. Nt-C215 expression is highly induced in leaf tissue by jasmonate treatment. Cellular transport using yeast cells strongly suggested nicotine efflux activity of C215. The possible role of this transporter in nicotine translocation will also be discussed.
1) Morita, Shitan et al. (2009) PNAS 106: 2447-2452.
