guest ::
| Home > Publications database > Combining an 11C and 13 C labelling approach to track photosynthates into the root system andrhizosphere microbiota of maize |
| Home > Publications database > Combining an 11C and 13 C labelling approach to track photosynthates into the root system andrhizosphere microbiota of maize |
| Conference Presentation (After Call) | FZJ-2023-00595 |
; ; ; ; ; ; ; ; ; ;
2022
Abstract: Plants transport substantial amounts of fresh photosynthates into their root system. From there, the photosynthates are par-tially released into the rhizosphere by rhizodeposition, which promotes interactions with microorganisms. Little is known aboutthe spatial distribution of photosynthates within the root system, and how these distributional patterns relate to rhizodepositionand the assembly of rhizosphere microbial communities. To assess root-internal photosynthate distribution, we labelled youngmaize plants with short-lived 11CO2 on days 14 and 21 after sowing. 11C allocation within the root system was then visualized usingnon-invasive positron emission tomography (PET) in combination with magnetic resonance imaging (MRI). The same plants werelabelled with the stable isotope 13CO2 for 6 consecutive days in order to trace the path of photosynthates into the rhizosphereand microbiota. Roots and rhizosphere soil were harvested on day 22, using the previously acquired PET/MRI scans to target rootregions with distinct photosynthate levels. Rhizosphere organisms that consumed 13C-labelled photosynthates were identifiedby DNA stable isotope probing followed by amplicon sequencing. Isotope ratio mass spectrometry (IRMS) was used to quantify13C in rhizosphere soil. The visualization and quantification of root-internal 11C by PET combined with MRI revealed an increasedaccumulation of photosynthates in root tips, particularly in young crown root tips. This pattern was partially reflected in thedistribution of 13C in the rhizosphere as determined by IRMS. Previous results of PET/MRI guided rhizosphere sampling alreadyrevealed a slight effect of photosynthate distribution within the root system on the local microbial community structure. Now,this effect is being tested with a more sensitive method that focuses on the direct microbial consumers of photosynthates bycombining 11CO2 labelling with 13C stable isotope probing. During the conference, the results of microbial community analysis willbe discussed, along with the associated root-internal and -external photosynthate allocation.
|
The record appears in these collections: |