What controls carbon sequestration in plants under which conditions?

Tim Nies; Marvin van Aalst; Nima Saadat; Josha Ebeling; Oliver Ebenhöh

doi:10.1016/j.biosystems.2023.104968

What controls carbon sequestration in plants under which conditions?

Biosystems. 2023 Sep:231:104968. doi: 10.1016/j.biosystems.2023.104968. Epub 2023 Jul 5.

Authors

Tim Nies¹, Marvin van Aalst², Nima Saadat³, Josha Ebeling², Oliver Ebenhöh³

Affiliations

¹ Institute of Theoretical and Quantitative Biology, Heinrich Heine University, Düsseldorf, 40225, North Rhine-Westphalia, Germany. Electronic address: tim.nies@hhu.de.
² Institute of Theoretical and Quantitative Biology, Heinrich Heine University, Düsseldorf, 40225, North Rhine-Westphalia, Germany.
³ Institute of Theoretical and Quantitative Biology, Heinrich Heine University, Düsseldorf, 40225, North Rhine-Westphalia, Germany; Cluster of Excellence on Plant Sciences, Heinrich Heine University, Düsseldorf, 40225, North Rhine-Westphalia, Germany.

PMID: 37419275
DOI: 10.1016/j.biosystems.2023.104968

Abstract

Photosynthetic organisms use photosynthesis to harvest sunlight and convert the solar energy into chemical energy, which is then used to reduce atmospheric carbon dioxide into organic molecules. This process forms the basis of all life on Earth, and stands at the beginning of the food chain which feeds the world population. Not surprisingly, many research efforts are currently ongoing aiming at improving growth and product yield of photosynthetic organisms, and several of these activities directly target the photosynthetic pathways. Metabolic Control Analysis (MCA) shows that, in general, the control over a metabolic flux, such as carbon fixation, is distributed among several steps and highly dependent on the external conditions. Therefore, the concept of a single 'rate-limiting' step is hardly ever applicable, and as a consequence, any strategy relying on improving a single molecular process in a complex metabolic system is bound to fail to yield the expected results. In photosynthesis, reports on which processes exert the highest control over carbon fixation are contradictory. This refers to both the photosynthetic 'light' reactions harvesting photons and the 'dark' reactions of the Calvin-Benson-Bassham Cycle (CBB cycle). Here, we employ a recently developed mathematical model, which describes photosynthesis as an interacting supply-demand system, to systematically study how external conditions affect the control over carbon fixation fluxes.

Keywords: Carbon sequestration; Electron transport; Mathematical model; Metabolic control theory.