Fig. 3

Phylogenetic placement of metagenomic and metatranscriptomic reads showing the community-wide response of As(III)-oxidizing and As(V)-reducing bacteria and archaea to As contamination. Phylogenetic placement of As oxidation and reduction genes, i.e., A aioA, B arxA, C arrA, and D arsC2, which carry reads identified in metagenomes (DNA reads) and metatranscriptomes (RNA reads) from As-contaminated and As-noncontaminated paddy soils. Here, the metagenomes and metatranscriptomes from the same As level (i.e., 24 As-contaminated samples and 12 As-noncontaminated samples) were combined. The pie size indicates the number of DNA (in blue) and RNA (in red) reads, and the ratio indicates the transcriptional activity for each clade (i.e., the fraction of RNA versus DNA reads assigned to the taxa with the same thresholds for a match). The clades are colored on the outside on the basis of the taxon type, e.g., Pseudomonadota (blue) and Chloroflexota (yellow)