Fig. 5

Relative abundances of the SIR COGs in Actinobacteriota and Proteobacteria stenohaline MAGs and phylogeny of COG0168. a–d Relative abundances of the SIR COGs in stenohaline MAGs affiliated with Actinobacteriota and Proteobacteria. All p values fall within the 95% confidence interval of bootstrap tests and are marked with solid blue dots. Number of MAGs involved in statistical calculations: low-salinity category Actinobacteriota, n = 17; low-salinity category Proteobacteria, n = 11; intermediate-salinity category Actinobacteriota, n = 10; intermediate-salinity category Proteobacteria, n = 16; high-salinity category Actinobacteriota, n = 3; and high-salinity category Proteobacteria, n = 13. Boxplot components, center lines, medians; box limits, 25^th and 75^th percentiles; whiskers, 1.5 × interquartile range from the 25^th and 75^th percentiles; red dots, outliers. Statistical significance symbols: ****p ≤ 0.0001, ***p ≤ 0.001, **p ≤ 0.01, *p ≤ 0.05, ns p > 0.05 (Kruskal–Wallis rank-sum test with Dunn’s multiple comparison test). Source data are provided in Additional file 2: Supplementary Table S10. e Phylogenetic tree constructed based on the amino acid sequences of COG0168 from all MAGs. Different background colors of the labels indicate different salinity categories, while the color bars indicate the microbial phyla and subunit types. The solid black dots label branches with a bootstrap value greater than 0.95