Year: 2020
Type: article
Abstract: The rhizosphere is a hotspot for microbial carbon transformations, and is the entry point for root polysaccharides and polymeric carbohydrates that are important precursors to soil organic matter (SOM). However, the ecological mechanisms that underpin rhizosphere carbohydrate depolymerization are poorly understood. Using Avena fatua, a common annual grass, we analyzed time-resolved metatranscriptomes to compare microbial functions in rhizosphere, detritusphere, and combined rhizosphere-detritusphere habitats. Transcripts were binned using a unique reference database generated from soil isolate genomes, single-cell amplified genomes, metagenomes, and stable isotope probing metagenomes. While soil habitat significantly affected both community composition and overall gene expression, the succession of microbial functions occurred at a faster time scale than compositional changes. Using hierarchical clustering of upregulated decomposition genes, we identified four distinct microbial guilds populated by taxa whose functional succession patterns suggest specialization for substrates provided by fresh growing roots, decaying root detritus, the combination of live and decaying root biomass, or aging root material. Carbohydrate depolymerization genes were consistently upregulated in the rhizosphere, and both taxonomic and functional diversity were highest in the combined rhizosphere-detritusphere, suggesting coexistence of rhizosphere guilds is facilitated by niche differentiation. Metatranscriptome-defined guilds provide a framework to model rhizosphere succession and its consequences for soil carbon cycling.
Source: The ISME Journal
Language: English
Subfield: Soil Science
Domain: Life Sciences
SDG: Life on land
Open Access status: bronze
Awards: G1079818582, G1143651532, G122673668, G1286236842, G1292182912, G1337544421, G1356433355, G137681422, G1414775356, G14554683, G1581387393, G1636790057, G1677143136, G1679750892, G1816284028, G1856093075, G2145270357, G223002938, G2337369775, G2699889991, G2812390658, G2857863752, G2880384052, G3083819904, G3432487278, G345329420, G3571461640, G365575497, G369607501, DIRECTING TRAFFIC IN THE RHIZOSPHERE: HOW PHAGE AND FAUNA SHAPE THE FLOW AND FATE OF ROOT CARBON THROUGH MICROBIAL PATHWAYS, G419881185, G42916606, G4343739756, G4430553229, G4501827968, G465867758, G498139845, G5076365615, G5296923526, G5374785022, G5390658509, G574795485, G6501917661, G654302390, G6679218506, G6816148754, G69709960, G7205239661, G7354628648, G7787287669, G805243471, G8326222658, G834277795, MAPPING SOIL CARBON FROM CRADLE TO GRAVE: DRAFTING A MOLECULAR BLUEPRINT FOR C TRANSFORMATION FROM ROOTS TO STABILIZED SOIL ORGANIC C, G8948921362, G969889393, G991281326
OpenAlex ID: W2999342455