Fig. 2

The distribution and abundance response of defense systems to Cr-induced stress. A Defense islands on the genomes. B The distribution patterns of defense systems within prokaryotes. C The number of defense system genes per unit length of MAGs (kb). D The number of defense systems per unit length of MAGs (kb). E Relative abundance of contigs with antiviral defense systems. (C, clean soil from the site (Cr(VI), 0.09 mg/kg); P, Cr-polluted soil from the site (Cr(VI), 665 mg/kg); C-0, C-10, and C-100 respectively refer to microcosm systems with the addition of Cr(VI) concentrations of 0, 10, and 100 mg/kg, and inoculation with microbiome from clean soil; P-0, P-10, and P-100 respectively refer to microcosm systems with the addition of Cr(VI) concentrations of 0, 10, and 100 mg/kg, and inoculation with microbiome from polluted soil. Boxplot components, center lines, medians; box limits, 25th and 75th percentiles; whiskers, 1.5 × interquartile range from the 25th and 75th percentiles; statistical significance symbols: * p ≤ 0.05, ns p > 0.05 (Wilcoxon rank sum test)