Outlier scaffolds encodes genes with functions in reproduction, stress responses, and production of volatile compounds
Although there overall are low levels of genetic differentiation between the morphological and genomic groups of specimens, there are 157 scaffolds with high F ST between groups of specimens (top 1% outliers) potentially indicating signs of divergent selection. A total of 1,846 Mentha transcripts (Figueroa-Pérez et al., 2018; Jin et al., 2014) have a top BLAST match longer than 300 bp with an e-value less than 1e-5 to one of the 1%F ST-outlier scaffolds. Of these, 534 transcripts have a top BLAST match longer than 100 and an e-value less than 1e-5 to a total of 116 different entries in UniProt (The UniProt Consortium, 2021), and could thus be annotated. The vast majority (82; 71%) were matches to a plant record and most of these have a described function (Table S4). Although the functions are diverse, nine transcripts were annotated to have functions relating to reproduction/fertility, and in particular to pollen recognition (Table S4). In addition, there were eight transcripts annotated to functions relating to pathogen response, eight had functions related to abiotic stress response, and there were five annotations involving DNA recombination/transposition (Table S4). Of particular interest are the three transcripts with functions in the biosynthesis of volatile compounds (VOCs; Table S4) which potentially are involved in the production of the characteristic aromatic compounds of mints.