Genes associated with elevated oxidative enzyme activities in arid systems have not been well-characterized. To link measured oxidative activities with specific enzymes, we assembled protein-coding reads from the rhizospheres (RHZ) of two aridland grasses. Targeted gene scans for open reading frames, encoding genes potentially involved in lignin modification, resulted in 127 distinct assembly products. The putative genes included those significantly similar to Class II secretory fungal peroxidases. These genes are expressed at sufficiently high levels for assembly, annotation and differentiation across experimental conditions, and they demonstrate the interplay of root systems, environment and plant microbiomes. The genes assembled also included copper-dependent lytic polysaccharide monooxygenases. We detail the enzymes in the host grass RHZs and present a preliminary taxonomic microhabitat characterization. Our findings provide support for biologically-mediated Fenton chemistry in the root zones of desert grasses, and provide insight into aridland carbon flow. These results also demonstrate a hyperdiverse microbial community. Both rRNA and mRNA sequences were dominated by bacteria, followed by fungal sequence abundance. Among notable fungal sequences were those from members of the arbuscular mycorrhizal fungi (Glomeromycota), which though abundant in this study we rarely observed in previous PCR-based surveys.