P18 - Carbon Allocation & Microbiota

Visualization and quantification of spatiotemporally resolved carbon allocation within the root system and rhizosphere microbiota of maize

C flow scheme

The primary input of carbon in soil occurs via the root system of plants. Carbon fixed in photosynthesis is used to build the structure of the root system, to provide energy for root functions, and constitutes most of the exudates released into the rhizosphere, which fuel soil microbial activity and growth. There is increasing evidence that carbon allocation is highly dynamic in space and time within root, soil and soil microbial pools. The patterns and processes underlying these dynamics are little understood.
This project proposes to visualize and measure the dynamics of carbon movement from shoot to root to the rhizosphere microbiota. We will address the question as to whether the amount and spatial distribution of recently fixed carbon in root systems influences the rhizosphere microbiota locally. The dynamic distribution of carbon in the root system will be studied in relation to the rhizosphere microbiota to understand how photosynthetic carbon influences the rhizosphere according to root type, root zone, root age, root surface morphology (root hairs and lateral roots), and soil texture.
We will combine imaging methods to visualize root architecture and photosynthetically fixed carbon in roots. Images of roots grown in soil will be obtained by Magnetic Resonance Imaging (MRI). Positron Emission Tomography (PET) will be applied to detect the short-lived 11C isotope to trace carbon flow within the root, and analyzed by co-registration of PET and MRI images. The method is extended by using the stable 13C isotope to trace carbon in the microbial pool in the rhizosphere. We will track carbon transfer into different trophic levels of the microbiota (bacteria, fungi and protists) using the RNA based stable isotope probing approach (RNA-SIP), and position them in space and time in relation to root age and root carbon allocation.

Link to English scientific abstract

Link to German scientific abstract