Reimport of carbon from cytosolic and vacuolar sugar pools into the Calvin–Benson cycle explains photosynthesis labeling anomalies

Journal Article · 07 March 2022 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.2121531119 · OSTI ID:1854025

Xu, Yuan  ^[1]; Wieloch, Thomas  ^[2]; Kaste, Joshua A. M.  ^[3]; Shachar-Hill, Yair  ^[1]; Sharkey, Thomas D.  ^[4]

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1. Department of Plant Biology, Michigan State University, East Lansing, MI 48824
2. MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
3. Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824
4. MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, Plant Resilience Institute, Michigan State University, East Lansing, MI 48824

Significance Photosynthesis metabolites are quickly labeled when ¹³ CO ₂ is fed to leaves, but the time course of labeling reveals additional contributing processes involved in the metabolic dynamics of photosynthesis. The existence of three such processes is demonstrated, and a metabolic flux model is developed to explore and characterize them. The model is consistent with a slow return of carbon from cytosolic and vacuolar sugars into the Calvin–Benson cycle through the oxidative pentose phosphate pathway. Our results provide insight into how carbon assimilation is integrated into the metabolic network of photosynthetic cells with implications for global carbon fluxes.

• Research Organization: Michigan State University, East Lansing, MI (United States)
• Sponsoring Organization: Michigan State University; National Institutes of Health (NIH); National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB)
• Grant/Contract Number: FG02-91ER20021
• OSTI ID: 1854025
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 11 Vol. 119; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English