Fig. 1.

Global transcriptional patterns of Trichodesmium communities in the North Atlantic subtropical gyre (NASG) and North Pacific subtropical gyre (NPSG). Correspondence analysis (CA) of the global metatranscriptome. CA ordinations of communities of the NASG and NPSG are shown, with significant (p < 0.05) environmental vectors fitted using the vegan function envfit [65]. Arrows indicate the direction of the (increasing) environmental gradient, and their lengths are proportional to their correlations with the ordination. 95% Confidence ellipses are indicated for each of the sample types by ocean basin. Discrete values for nitrite and nitrate ($N{O}_2^{-}$ + $N{O}_3^{-}$), phosphate ($P{O}_4^{3-}$), dissolved iron (dFe) in the NPSG, the climatological average for dFe in the NASG, and temperature (Temp) used in this analysis are available in Table S1. *In the NASG, dFe was computed as the climatological average (Table S1)