GO and KEGG functional enrichment analyses of the differentially methylated genes.

(A) Top 21 significant Gene Ontology (GO) terms of differentially methylated genes for A. ferrooxidans under Fe²⁺ and RISCs oxidizing conditions. (B and C) KEGG pathway enrichment analysis of hypermethylated (B) and hypomethylated genes (C) of A. ferrooxidans under Fe²⁺ and RISCs oxidizing conditions. Hypermethylated genes are genes with an increased degree of methylation in the Fe²⁺ oxidizing condition compared with the RISCs oxidizing condition, and hypomethylated genes are genes with a decreased degree of methylation in the Fe²⁺ oxidizing condition compared with the RISCs oxidizing condition. The fold change represents the degree of enrichment of the differentially expressed genes. The Y-axis shows the names of the enriched pathways. The area of each node represents the number of observed genes. The significance test is represented by a color scale.