Fig. 2: Nitrogen fixation activity and assimilation in the coral holobiont after 10 days of heat stress.
From: Heat stress reduces the contribution of diazotrophs to coral holobiont nitrogen cycling
A Nitrogen fixation activity of coral holobionts (n = 5 per treatment) was quantified via the acetylene reduction assay. B Net assimilation of diazotroph-derived nitrogen in the coral holobiont (n = 5 per treatment) quantified by 15N2 isotope labeling and bulk stable isotope analysis. C Nitrogen fixation activity and assimilation of diazotroph-derived nitrogen show a positive correlation across colonies (symbols) under control (blue) and heat stress conditions (red) with corresponding confidence intervals (gray). Pearson’s correlation coefficients (r) correspond to correlations among each condition of the corresponding color. Samples from both control and heat stress conditions of the colony with the highest enrichment (ellipse) were imaged in detail using the NanoSIMS ion microprobe. Bars and error bars indicate mean ± SE. Asterisks indicate significant differences between treatments (p < 0.05).
