Display Accessibility Tools

Accessibility Tools

Grayscale

Highlight Links

Change Contrast

Increase Text Size

Increase Letter Spacing

Dyslexia Friendly Font

Increase Cursor Size

Recycling carbon in photosynthesis

Isoprene and photosynthetic metabolism labeling experiments provided evidence that glucose is recycled back into photosynthetic metabolism.


Figure of fluorescence measurements, corrected and uncorrected.

Glucose and fructose can reenter photosynthetic metabolism (the Calvin Benson cycle) through glucose 6-phosphate shunts (in orange). At normal temperature only the outer (cytosolic) shunt is active. Temperature stress speeds the outer shunt and turns on the inner (chloroplast) shunt.

Scientific Achievement

Discovered evidence that glucose is recycled back into photosynthetic metabolism.

Significance and Impact

The pathway for converting carbon dioxide to starch and sucrose in photosynthesis was discovered by labeling using isotopes of carbon. However, not all carbon in the pathway becomes labeled. A similar phenomenon was known for isoprene emission, not all isoprene is labeled when carbon isotopes are fed. We showed that these observations are linked, isoprene provides a window on photosynthesis.

Research Details

  • As much as 40% of isoprene emitted from a leaf fed an isotope of carbon does not become labeled. This varies with stress.
  • We showed that this is because photosynthesis metabolites do not label fully.
  • Isoprene accurately reflects the labeling of photosynthesis metabolites.
  • Modeling showed that this is likely caused by a flow of unlabeled glucose into photosynthetic metabolism through a shunt that bypasses part of photosynthesis.
  • The amount of glucose that follows this pathway varies with stress, for example it is much higher at high temperature.
  • Isoprene provides a non-destructive method for measuring this flow of carbon.

Related people: Thomas D. Sharkey (CA), Alyssa L. Preiser, Sarathi M. Weraduwage, Linus Gog

DOI: 10.1042/BCJ20200480

Download the highlight

This work was primarily funded by the US Department of Energy, Office of Basic Energy Sciences.

Top Stories

MSU's Jianping Hu receives NSF grant to shed light on plant growth, reproduction MSU's Jianping Hu receives NSF grant to shed light on plant growth, reproduction

Jianping Hu, professor at the MSU-DOE Plant Research Laboratory (PRL) and the Department of Plant Biology, received a $900,000 grant from the National Science Foundation (NSF) to study the motility of cellular energy organelles, peroxisomes and mitochondria in particular, along the cytoskeleton in Arabidopsis thaliana.

Plant "ER": Advanced genomics illuminate new mechanisms for stress mitigation Plant "ER": Advanced genomics illuminate new mechanisms for stress mitigation

As our planet’s climate continues to be unpredictable, understanding how plants respond to adverse environmental conditions becomes essential. Improving crop productivity will be vital to feed the nine billion people estimated to be alive in 2050.

2022 Anton Lang Memorial Award winners announced 2022 Anton Lang Memorial Award winners announced

Grad student Philip Engelgau and postdoc Peipei Wang have been awarded the 2022 Anton Lang Memorial Award at a ceremony which took place on Monday, April 25, 2022. This year’s lecture was given by Professor Emeritus Govindjee from the University of Illinois at Urbana-Champaign.