Differences between plant species in rhizosphere metatranscriptome function

It is well known that plants can modify the taxonomic composition and metabolic activity of microbes in the vicinity of their roots. We have sequenced metatranscriptomes of the rhizospheres of wheat, oat and pea and of unplanted soil after depletion of ribosomal RNA, to an estimated depth of 0.12% (0.81 high quality non-ribosomal reads) and, where possible, assigned the non-ribosomal sequences to taxonomic groups and to metabolic pathways. Wheat has the weakest effect on its rhizosphere, with a non-significant increase in transcriptional activity and only minor differences in taxonomic composition, while pea shows a 2.5 fold increase in transcription and substantial changes in taxonomic composition, including a large increase in the abundance of fungal transcripts. Abundance of key metabolic pathways differs between rhizospheres and non-planted soil, but metabolic differences between plants are more subtle than taxonomic differences.