Fig. 2.

Change in allele frequency in 5 of 30 outlier polymorphisms with high treatment effect in response to elevated CO₂ (A–E; P < 0.0001) and one randomly selected polymorphism (F; P > 0.05). (A and B) Alanine aminotransferase 2 enzyme (A) and splicing factor 3b (B) show the greatest treatment effects and perform functions related to metabolism and RNA processing, respectively. (C) Echs1 protein (enoyl CoA hydratase) is a mitochondrial enzyme involved in lipid metabolism. (D and E) FGD6 regulates the cytoskeleton and cell shape (D), and the glutamate receptor is involved in ion transport (E). Red lines mark observed change in allele frequency between control (400 µatm–days 1 and 7 averaged) and treatment (900 µatm–day 7) cultures. An empirical null distribution (gray) was generated by the random permutation of samples and recalculation of treatment effect. These five genes span the diverse protein functions and range of change in allele frequency represented across the 30 outliers. See Table S3 for the complete list of 30 outlier genes with protein function annotations.