Data from: Phylogenomic mining of the mints reveals multiple mechanisms contributing to the evolution of chemical diversity in Lamiaceae

The evolution of chemical complexity has been a major driver of plant
diversification, with novel compounds serving as key innovations. The
species-rich mint family (Lamiaceae) produces an enormous variety of
compounds that act as attractants and defense molecules in nature and are
used widely by humans as flavor additives, fragrances, and anti-herbivory
agents. To elucidate the mechanisms by which such diversity evolved, we
combined leaf transcriptome data from 48 Lamiaceae species and four
outgroups with a robust phylogeny and chemical analyses of three terpenoid
classes (monoterpenes, sesquiterpenes, iridoids) that share and compete
for precursors. Our integrated chemical-genomic-phylogenetic approach
revealed that: 1) gene family expansion rather than increased enzyme
promiscuity of terpene synthases is correlated with mono- and
sesqui-terpene diversity; 2) differential expression of core genes within
the iridoid biosynthetic pathway is associated with iridoid
presence/absence; 3) generally, production of iridoids and canonical
monoterpenes appeared to be inversely correlated; and 4) iridoid
biosynthesis was significantly associated with expression of geraniol
synthase, which diverts metabolic flux away from canonical monoterpenes,
suggesting that competition for common precursors can be a central control
point in specialized metabolism. These results suggest that multiple
mechanisms contributed to the evolution of chemodiversity in this
economically important family.