Fig. 1 in Alkaloid chemophenetics and transcriptomics of the Nicotiana genus

Fig. 1. Current state-of-the-art picture of alkaloid biosynthesis in Nicotiana genus. Gene acronyms are provided in red next to the enzymatic steps they correspond to. Each gene acronym is explained in boxes with full gene names. Compound full names are provided in black, with additional 2D structure representation of alkaloids: anabasine, nicotine, nornicotine, anatabine, cotinine, myosmine as well as nicotinic acid. Additional 2D structures are also presented for alkaloids intermediates: Δ1-piperdiene, N-methyl-Δ1-pyrrolinium cation, 3,6-dihydronicotinic acid, and 2,5-dihydropyridine. In faded green, field steps of polyamine biosynthesis are presented, whereas the faded red field encloses steps limited to plastid and root tissue. Question marks are located next to enzymatic steps that are currently only hypothesized and have not yet been confirmed by independent studies. The figure is based on a review by Dewey and Xie (2013) and subsequent studies, that characterized the functions of further genes, namely LDC (Bunsupa et al., 2014) and NUP1 (Kato et al., 2015), in the alkaloid biosynthetic pathway.