Professor ZHOU Youping's team has made significant progress in the study of the oxygen isotope composition of plant sugar molecules
Author: MA Ran
Release: DU Yang
Translator: HOU Yumo
The team of Isotopomics in Chemical Biology led by Professor ZHOU Youping of the College of Chemistry and Chemical Engineering of SUST has taken the lead in developing the complete intramolecular 18O/16O Profile of the Glucose Unit in a starch of C4 Origin, Novel Position-Specific 18O/16O Measurement of Carbohydrates through the efforts of the past 4 years. The relevant results were published in the Natural Index journal ‘Analytical Chemistry’. Youth teacher MA Ran is the first author, and Ph.D. student ZHAO Yu, 2019 Admission, is the second author of the paper (Maet al., 2020; Anal. Chem. , https: //pubs.acs.org/doi/pdf/10.1021/acs.analchem.9b05314; Maet al., 2018; Anal. Chem., 90, 10293-10301 ;). And the Third Institute of Oceanography, Ministry of Natural Resources participates in the study.
The oxygen isotope composition (18O/16O) of plant-derived glucose molecules is a faithful recorder of plant photosynthesis, metabolism, physiology, and environmental information. However, determining the molecular oxygen isotope composition remains a huge technical challenge.
The Isotopomics in Chemical Biology group led by Professor ZHOU Youping has developed a combination of synthetic organic chemistry (Figure 1), gas chromatography / pyrolysis / isotopic ratio mass spectrometry (GC / Py / IRMS), and chemical kinetic calculations, which first demonstrate the heterogeneous distribution of oxygen isotope in the glucose molecule of plant starch derived from C4 (Figure 2). The results show that O-2 is slightly enriched in the relative molecular average of 18O, O-3 is relatively enriched and O-4 and O-6 are relatively depleted. The speculation of relative depletion of O-6 is related to the least possibility of the exchange of oxygen atoms on C-5 in RuBP (ribulose 1.5-diphosphate) during leaf photosynthesis with the evaporation and enrichment of water in the leaf. Thus O-6 is most likely to record the signal of the root water source.
The research results will help improve the mechanism of tree-ring cellulose oxygen isotope fractionation, and open a technical door for cracking the metabolic, physiological, environmental, and climate information recorded in the oxygen isotope of sugar plant molecules.
Strategies and synthetic chemical approaches for obtaining oxygen isotope composition at a single location
Oxygen isotope distribution pattern of C4 source plant starch glucose unit
This research work was supported by the National Natural Science Foundation of China [41773032 and 41973072].
（1）Ma, R.; Zhao, Y.; Liu, L.; Zhu, Z.; Wang, B.; Wang, Y.; Yin, X.; Su, J.; Zhou, Y., Novel Position-Specific18O/16O Measurement of Carbohydrates. II. The Complete Intramolecular18O/16O Profile of the Glucose Unit in a Starch of C4 Origin.Analytical Chemistry2020, 10.1021/acs.analchem.9b05314.
（2）Ma, R.; Zhu, Z.; Wang, B.; Zhao, Y.; Yin, X.; Lu, F.; Wang, Y.; Su, J.; Hocart, C. H.; Zhou, Y., Novel Position-Specific18O/16O Measurement of Carbohydrates. I. O-3 of Glucose and Confirmation of18O/16O Heterogeneity at Natural Abundance Levels in Glucose from Starch in a C4 Plant.Analytical Chemistry2018,90(17), 10293-10301.