Tobacco nicotine uptake permease (NUP1) affects alkaloid metabolism.

An effective plant alkaloid chemical defense requires a variety of transport processes, but few alkaloid transporters have been characterized at the molecular level. Previously, a gene fragment encoding a putative plasma membrane proton symporter was isolated, because it was coordinately regulated with several nicotine biosynthetic genes. Here, we show that this gene fragment corresponds to a Nicotiana tabacum gene encoding a nicotine uptake permease (NUP1).

Cloning and characterization of a Nicotiana tabacum methylputrescine oxidase transcript.

The oxidative deamination of N-methylputrescine is an essential step in both pyridine and tropane alkaloid biosynthesis. Reverse genetic approaches have not resulted in the cloning of a methylputrescine oxidase gene (MPO). However, we have used a homology-based approach to clone a full-length tobacco MPO1 cDNA.

The A and B loci in tobacco regulate a network of stress response genes, few of which are associated with nicotine biosynthesis.

Nicotine biosynthesis in Nicotiana tabacum is under genetic control by the A and B loci. Plants containing semi-dominant mutations at both the A and B loci (i.e.