Project Details
Projekt
A molecular perspective on plant-microbiome interactions during rhizosphere development
Applicant
Dr. Oliver Lechtenfeld
Subject Area
Soil Sciences
Term
from 2018 to 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 403669053
Self-organization in the rhizosphere generates multi-faceted chemical gradients in which the plant-microbe interplay is a key driver. The soil solution is a crucial component of the rhizosphere, where chemical gradients of organic molecules first develop upon growth of roots and introduction of plant-derived carbon. Soil type, environmental factors, plant genotype, microbial community, etc. then all drive the chemical evolution of the soil solution. Emerging chemical and biological pattern of a developing rhizosphere reflect the complex interactions and feed-back loops between these drivers. This proposal aims at investigating the spatio-temporal development of small-scale molecular gradients of organic carbon in early rhizosphere development from non-rhizosphere pre-conditions in soil column experiments which are fully embedded into the central platform experiments of the priority programme (PP). Micro suction cups for soil solution sampling and ultrahigh-resolution mass spectrometry (FTICR-MS) to analyze the organic matter composition will be the major tools. Our key hypothesis is that the convergent evolution of soil solution molecular gradients in the rhizosphere is mainly driven by rapid microbial turnover of root derived carbon. To this end, we will use two Zea mays genotypes (wildtype and rth3 mutant) grown in soil columns equipped with micro suction cups, bioassays and stable isotope labels to track the release of organic molecules by roots, the transformation of these by the microbial community and to map the spatial extent and dynamics of the rhizosphere. FTICR-MS provides the highest possible “chemical resolution” for intact molecules in soil solution while micro suction cups are able to sample the most dynamic soil compartment and its carbon pool in the rhizosphere at a high temporal resolution. Beyond that, we will also develop molecular imaging methods, extending the spatial resolution while conserving molecular chemical information. This novel and unique combination of state-of-the-art tools in rhizosphere research will expand our understanding of carbon fluxes far beyond a bulk budget and help to identify important drivers in a developing rhizosphere and assess their impact on chemical gradients.Studying the spatio-temporal dynamics of soil solution chemistry in unprecedented detail will give valuable insights into the self-organization and resilience of the rhizosphere, will help to better understand how distinct soil processes shape the chemical composition and diversity of the rhizosphere, will close the knowledge gap between root exudate, soil chemistry and microbial ecology focused research, and will notably contribute to the systems approach of the PP. Our proposal thus directly interacts with and connects to projects related to carbon acquisition and turnover in soils (e.g. priming, sequestration), to microbial ecology and community dynamics as well as projects applying chemical imaging and stable isotope methods.
DFG Programme
Priority Programmes
Co-Investigator
Professor Dr.-Ing. Thorsten Reemtsma
