Shift of microbial taxa and metabolisms relying on carbon sources of rhizodeposits and straw of Zea mays L

authored by

Yingyi Fu, Yu Luo, Jiejun Qi, Xinhua He, Haoqing Zhang, Georg Guggenberger, Jianming Xu

Abstract

Decoding the fundamental taxa that decompose crop rhizodeposits (rhizo-C) and/or straw residue (straw-C) is crucial for understanding the role of plant-derived carbon (C) in driving microbial community assembly and consequent C decomposition. Here, a parallel ¹³C-labeling design, DNA-SIP, and metagenomics techniques were combined to separate maize rhizo-C utilizers from straw-C utilizers in agriculture soils containing both C sources. Also, by comparing bacterial utilizers and their C metabolisms in soils amended with a single C source (e.g., straw-¹³C only) and two C sources (e.g., straw-¹³C and rhizo-¹²C), we investigated the shift of composition and metabolisms of soil bacterial utilizers responding to C sources shift (e.g., compositional and metabolic changes of straw-¹³C utilizers from soil containing straw-¹³C to soil containing both straw-¹³C and rhizo-¹²C). We revealed i) Proteobacteria predominantly utilized rhizo-¹³C, while Firmicutes dominated the community specializing in straw-¹³C decomposition in soil containing both straw-C and rhizo-C; ii) the planted maize (i.e. rhizo-C input) changed community composition and metabolisms of straw-C utilizers, which shifted from K-strategists characterized by an enrichment of lignin-degrading genes to r-strategists which exhibited an enrichment of genes related to polysaccharide degradation. This metabolic shift of straw-C utilizer ultimately reduced straw-¹³C mineralization by 25.6% when maize was planted. This study identified the distinct utilizers of rhizo-C and straw-C in soils containing both C sources, and shed light on the shift of bacterial community and their metabolic activities responding to the changes of maize-derived C sources.

Organisation(s)

Institute of Soil Science

External Organisation(s)

Zhejiang University
Northwest Agriculture and Forestry University
University of Western Australia
University of California at Davis
Ningbo University

Type

Article

Journal

Soil Biology and Biochemistry

Volume

198

ISSN

0038-0717

Publication date

11.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Microbiology, Soil Science

Electronic version(s)

https://doi.org/10.1016/j.soilbio.2024.109578 (Access: Closed)