Additional file 5 of Spatial organization of the kelp microbiome at micron scales

Additional file 4: Figure S3. Bacterial abundance on surface of old and young tissue in N. luetkeana. (A) Cell abundance differed depending on collection site and portion of the kelp blade sampled. Cell counts per field of view (FOV) are shown as boxplots showing all data points as well as the median (line) and first and third quartiles for each taxon; n = 20 FOV for Tatoosh base and tip and 16 FOV for Squaxin. Bacterial abundance on older tissue (tip) is higher compared to young tissue (base) or declining kelp (Squaxin). Collection site and portion of the kelp blade sampled (Tip; Base; Mid = middle) are indicated in the x-axis labels. (B) Relative abundance estimated by imaging is comparable to that estimated by 16S rRNA gene sequencing. Relative abundance based on total cell counts from individual samples is shown; n = 2 to 9 FOV per sample. Sample numbers (cf. Table S1) and portion of the kelp blade sampled (T = tip, B = Base, M = middle) are indicated in the x-axis labels. Collection site is shown at the bottom. Abundance estimates from imaging and from 16S rRNA gene sequencing (Fig. 1) were similar despite the different methods and different scale of sampling: imaging was from fields of view of 0.04 mm2 while DNA extraction for sequencing was from an entire tissue sample of 2 cm2 [10].