Figure 6. Expression patterns of Tropane and Pyridine alkaloids biosynthetic unigenes over C. yanhusuo bulb development.

(a) Biosynthetic pathways are based on Dewey and Xie⁵⁵, Kushwaha et al.⁵⁶ and Bedewitz et al.⁵⁷. Black arrows, N-methyl-Δ¹-pyrrolinium cation biosynthesis; blue arrows, various tropane alkaloids biosynthesis; pink arrows, pyridine alkaloid biosynthesis, represented by nicotine biosynthesis. Enzymes for which corresponding genes have been isolated from other plants are shown in green next to the arrows. Two or more known steps between two intermediates, whose cDNA sequences haven’t been isolated, are omitted here but indicated by continuous arrows. Full names of enzymes by abbreviations are provided in Table S1. NAMN, nicotinic acid mononucleotide. (b) Expression patterns of representative DEGs. Illustrations are provided in Fig. 4b.