Extended Data Fig. 4: Distribution, abundance and activity of Ca. C. neptuna.
From: Terrestrial-type nitrogen-fixing symbiosis between seagrass and a marine bacterium
(a) Stitched epifluorescence images (black-and-white inverted) of root cross-sections from April 2016 (left), June 2014 (middle) and August 2016 (right) showing primary locations of Ca. C. neptuna cells (as visualized by FISH) in red (signal-amplified for easier visualization; Methods), (b) Epifluorescence image (from panel a) indicating the different root tissues (as in c), (c) absolute and relative abundance of Ca. C. neptuna cells (visualized by FISH) in the different root tissues of individual P. oceanica root sections (0.5 – 1.0 µm thickness), (d) Correlative epifluorescence (FISH and autofluorescence) and nanoSIMS (15N/14N) images (left) with the retrieved surface areas and correlative nanoSIMS data for Ca. C. neptuna cells (middle) and root tissue (right) (Methods), x- and y-axes are in pixels with 256 pixels = 20 µm, and the color scale represents the 15N/14N ratio; (e) single-cell 15N2 fixation activity (Ca. C. neptuna cells) or transfer of freshly fixed N (root tissue) as relative incorporation per day in Ca. C. neptuna cells, root tissue with Ca. C. neptuna cells in the same image (roots with cells) and root tissue without Ca. C. neptuna cells in the same image (roots without cells) obtained from a total of 167 measurements as shown in (d) from two cross-sections.
