Figure 2.

Phylogenetic tree of O-methyltransferases (OMTs). (A) Graphical representation of the last and critical step of the methoxypyrazine biosynthesis pathway, where a S-adenosyl-l-Met (SAM)-dependent O-methyltransferase (OMT) converts 3-isobutyl-2-hydroxypyrazine (IBHP) into 3-isobutyl-2-methoxypyrazine (IBMP) producing S-Adenosyl-l-homo-Cys (SAHcy). (B) Phylogenetic tree illustrating the relation between the different alleles of the VviOMT clade. The VviOMT clade was divided into 4 subclades as reported in Guillaumie et al. (2013) (VviOMT1, VviOMT2, VviOMT3 and VviOMT4). The percentage of replicate trees in the bootstrap test clustering the associated sequences are shown next to the branches. Sequences of the different alleles identified in Carménère genome annotation are indicated in bold, green for the allele reported in the primary sequences and violet for the one in the haplotigs. These sequences were compared to PN40024 annotation and the VviOMT alleles reported for different genotypes in Guillaumie et al. (2013). The acronyms reported indicate the original genotype: Carménère (Car), Cabernet Sauvignon (CS), Pinot Noir (PN), Petit Verdot (PV); where more than one genotype was sharing the same allele, a coma separated list is reported. The amount of IBMP produced in vitro by the three recombinant VviOMT3 proteins is indicated in parenthesis (Supplementary data from Guillaumie et al. 2013).