Rhizosphere influence on microbial functions

consequence for temperature sensitivity of soil organic matter decomposition at early stage of plant growth

authored by

Jie Zhou, Chunyan Liu, Lingling Shi, Kazem Zamanian

Abstract

Aims: Accurate predictions of soil carbon (C) feedbacks to climate change depend on an improved understanding of temperature sensitivity (Q₁₀) of soil organic matter (SOM) decomposition. Although rhizosphere processes play a critical role in SOM decomposition, the rhizosphere effects on Q₁₀ and their underlying microbial mechanisms remain unclear. Methods: Natural abundance approach was used to measure the rhizosphere priming effect (RPE) of maize under two temperature regimes in a 50-day pot experiment. We further determined the impact of rhizosphere process on the Q₁₀ of SOM decomposition. Enzymatic kinetics, microbial growth rate, as well as ¹³C-phospholipid fatty acid (¹³C-PLFA) biomarkers were identified to evaluate the responses of microbial activity. Results: Warming relative to ambient increased the plant-derived C input, stimulated microbial growth rate, and enzyme activities by 87%, 23%, and 7–18%, respectively. Consequently, warming increased the RPE of maize up to 1-folds, and further caused a larger net C loss as compared to ambient after 50 days of transplanting. Gram negative bacteria and actinobacteria were important groups controlling the RPE, which was supported by the positive correlations between RPE and the abundance of gram negative and actinobacteria. Furthermore, we concluded a literature review and the results were consistent with our case study, where the presence of roots increased the temperature sensitivity of SOM decomposition by 0.17–0.56. This was because rhizodeposition activated microorganisms which produce more enzymes and increase SOM-derived substrate availability. This indicates that planted soils face higher risks of C emissions under future climate warming. Conclusions: Overall, root-soil interactions via RPE play a pivotal role in determining the temperature sensitivity of SOM decomposition.

Organisation(s)

Institute of Soil Science

External Organisation(s)

Nanjing Agricultural University
China Agricultural University
University of Tübingen
Kunming Institute of Botany Chinese Academy of Sciences
Nanjing University of Information Science and Technology

Type

Article

Journal

Plant and soil

Volume

494

Pages

95-109

No. of pages

15

ISSN

0032-079X

Publication date

01.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Soil Science, Plant Science

Sustainable Development Goals

SDG 13 - Climate Action

Electronic version(s)

https://doi.org/10.1007/s11104-023-06258-2 (Access: Closed)