Fig. 2: DMSP accumulation in Spartina anglica is associated with stress responses.

a Satellite image of Spartina anglica sampling sites at Stiffkey saltmarsh, taken from Google Maps. b Variability in DMSP accumulation in individual clumps of S. anglica harvested from the sites denoted in panel a. Samples identified as ‘highest accumulators’ (red) and ‘lowest accumulators’ (blue) were subjected to RNA-sequencing (n = 3 per clump per site, p = 8.3e-14 in one-way ANOVA). Letters indicate statistical significance after one-way ANOVA followed by Tukey test. c Volcano plot demonstrating contrasting gene expression profiles between highest and lowest DMSP accumulating clumps of S. anglica. Each dot represents a gene, with red dots indicating genes that are more highly expressed in highest accumulators, blue dots indicating genes that are lower, and grey dots denoting genes that are not significantly differentially expressed. Dotted lines indicate significance thresholds from DESeq2 analysis. Labelled dot refers to Ethylene Responsive Element Binding Protein 1 (EREBP1), a key stress responsive transcription factor in grasses. d Gene ontology enrichment analysis of differentially expressed genes from (c), demonstrating an enrichment of stress-responsive genes in highest DMSP accumulators. e Heatmap of pairwise Pearson correlations between measured variables (abundance of indicated elements and amino acids in S. anglica leaves), demonstrating negative linear relationship between DMSP and levels of nitrogen and proline, and positive linear relationship between DMSP and molybdenum (Mo). Crosses indicate that a relationship is not significant. Data represent mean ± one standard error. Source data are provided as a Source Data file.