Dynamics of oxygen and carbon dioxide in rhizospheres of Lobelia dortmanna - a planar optode study of belowground gas exchange between plants and sediment
Autor: | Kai Jensen, Gregor Liebsch, Ketil Koop-Jakobsen, Peter Mueller, Nikola Lenzewski, Robert J. Meier |
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Rok vydání: | 2017 |
Předmět: |
0106 biological sciences
Geologic Sediments Optics and Photonics Time Factors Physiology Lobelia dortmanna Plant Science Photosynthesis 010603 evolutionary biology 01 natural sciences Plant Roots chemistry.chemical_compound Total inorganic carbon Lobelia Rhizosphere biology Chemistry Sediment Carbon Dioxide biology.organism_classification Oxygen Microbial population biology Environmental chemistry Carbon dioxide DNS root zone 010606 plant biology & botany |
Zdroj: | The New phytologist. 218(1) |
ISSN: | 1469-8137 |
Popis: | Root-mediated CO2 uptake, O2 release and their effects on O2 and CO2 dynamics in the rhizosphere of Lobelia dortmanna were investigated. Novel planar optode technology, imaging CO2 and O2 distribution around single roots, provided insights into the spatiotemporal patterns of gas exchange between roots, sediment and microbial community. In light, O2 release and CO2 uptake were pronounced, resulting in a distinct oxygenated zone (radius: c. 3 mm) and a CO2 -depleted zone (radius: c. 2 mm) around roots. Simultaneously, however, microbial CO2 production was stimulated within a larger zone around the roots (radius: c. 10 mm). This gave rise to a distinct pattern with a CO2 minimum at the root surface and a CO2 maximum c. 2 mm away from the root. In darkness, CO2 uptake ceased, and the CO2 -depleted zone disappeared within 2 h. By contrast, the oxygenated root zone remained even after 8 h, but diminished markedly over time. A tight coupling between photosynthetic processes and the spatiotemporal dynamics of O2 and CO2 in the rhizosphere of Lobelia was demonstrated, and we suggest that O2 -induced stimulation of the microbial community in the sediment increases the supply of inorganic carbon for photosynthesis by building up a CO2 reservoir in the rhizosphere. |
Databáze: | OpenAIRE |
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