Thomas D. Sharkey

Thomas D. Sharkey is a plant biochemist who studies gas exchange between plants and the atmosphere. His research has covered (1) carbon metabolism of photosynthesis from carbon dioxide uptake to carbon export from the Calvin-Benson Cycle, (2) isoprene emission from plants, and (3) abiotic stress tolerance. Four guiding questions are: (1) how leaf photosynthesis affects plant yield, (2) does some carbon fixation follow an oxidative pathway that reduces sugar output but stabilizes photosynthesis, (3) why plants make isoprene, and (4) how plants cope with high temperature.

Thomas "Tom" D. Sharkey
Awards	University Distinguished Professor Fellow of the American Association for the Advancement of Science Fellow of American Society of Plant Biologists
Scientific career
Institutions	Michigan State University Australian National University University of Wisconsin-Madison
Thesis	Stomatal Responses to Light in Xanthium strumarium and other species
Doctoral advisor	Klaus Raschke
Website	bmb.natsci.msu.edu/faculty/thomas-d-sharkey/

Education and Training

Tom Sharkey obtained a BS degree in 1974 from Lyman Briggs College, a residential college within Michigan State University (MSU) focusing on the study of natural science and the history and philosophy of science. He obtained his PhD in 1980 from the Department of Botany and Plant Pathology (now Plant Biology) at MSU for research conducted in the MSU-DOE Plant Research Laboratory. His thesis work was carried out under the direction of Professor Klaus Raschke and was titled Stomatal Responses to Light in Xanthium strumarium and Other Species.

Professional Experience

After 2.5 years as a Post-doctoral Fellow in the Department of Environmental Biology at the Australian National University under the supervision of Professor Graham Farquhar, Sharkey spent five years (1982-1987) at the Desert Research Institute in Reno, Nevada. There he carried out experiments with the noted plant physiologist Professor Frits Went. He then went to the University of Wisconsin-Madison for 20 years where he held various administrative posts such as Chair of the Department of Botany, Director of the UW-Madison Biotron, and Director of the Institute for Cross College Biology Education. In 2008 Sharkey was recruited back to Michigan State University to become Chair of the Department of Biochemistry and Molecular Biology. In 2015 he was named a University Distinguished Professor.

Sharkey has been Series Editor for the book series Advances in Photosynthesis and Respiration and Senior Editor for the journal Plant, Cell & Environment. He was elected Fellow of the American Society of Plant Biologists in 2007 and Fellow of the American Association for the Advancement of Science in 2011.

Research

Sharkey studies the biochemistry and biophysics that underlie plant-atmosphere interactions especially photosynthesis and isoprene emission from plants. Significant accomplishments related to photosynthesis include the measurement of carbon dioxide concentration inside leaves,^[1] measurement of the biophysical resistance to carbon dioxide diffusion within leaves,^[2][3][4][5] elucidation of the biochemical feedback chain that explains how limitations in starch and sucrose synthesis reduce the efficiency of photosynthesis^[6] and demonstration that maltose is the primary metabolite exported from chloroplasts at night.^[7][8]

Significant accomplishments related to isoprene biosynthesis and emissions from plants include the first genomic sequence of an isoprene synthase,^[9] cloning isoprene synthases from ten different plant species,^[10] analysis of the evolution of isoprene synthases and enzymes needed to make the precursor to isoprene.

Heat stress was shown to be ameliorated by cyclic electron flow in photosynthesis.^[11]

References

1. Sharkey, TD.; et al. (1982). "A direct confirmation of the standard method of estimating intercellular partial pressure of CO₂". Plant Physiology. 69 (3): 657–659. doi:10.1104/pp.69.3.657. PMC 426273. PMID 16662268.
2. Sharkey, TD. (2012). "Mesophyll conductance: Constraint on carbon acquisition by C3 plants". Plant, Cell & Environment. 35 (11): 1881–1883. doi:10.1111/pce.12012. PMID 23043351.
3. Harley, PC.; et al. (1992). "Theoretical considerations when estimating the mesophyll conductance to CO₂ flux by analysis of the response of photosynthesis to CO₂". Plant Physiology. 98 (4): 1429–1436. doi:10.1104/pp.98.4.1429. PMC 1080368. PMID 16668811.
4. Loreto, F.; et al. (1992). "Estimation of mesophyll conductance to CO₂ flux by three different methods". Plant Physiology. 98 (4): 1437–1443. doi:10.1104/pp.98.4.1437. PMC 1080369. PMID 16668812.
5. Evans, JR; et al. (1986). "Carbon isotope discrimination measured concurrently with gas exchange to investigate CO₂ diffusion in leaves of higher plants". Functional Plant Biology. 13 (2): 281–292. doi:10.1071/pp9860281.
6. Yang, J.; et al. (2016). "Triose phosphate use limitation of photosynthesis: short-term and long-term effects". Planta. 243 (3): 687–698. doi:10.1007/s00425-015-2436-8. PMID 26620947. S2CID 1450506.
7. Weise, SE.; et al. (2005). "β-maltose is the metabolically active anomer of maltose during transitory starch degradation". Plant Physiology. 137 (2): 756–761. doi:10.1104/pp.104.055996. PMC 1065375. PMID 15665241.
8. Weise, SE.; Weber, A.; Sharkey, TD. (2004). "Maltose is the major form of carbon exported from the chloroplast at night". Planta. 218 (3): 474–482. doi:10.1007/s00425-003-1128-y. PMID 14566561. S2CID 21921851.
9. Sharkey, TD.; et al. (2005). "Evolution of the isoprene biosynthetic pathway in kudzu". Plant Physiology. 137 (2): 700–712. doi:10.1104/pp.104.054445. PMC 1065370. PMID 15653811.
10. Sharkey, TD; et al. (2013). "Isoprene synthase genes form a monophyletic clade of acyclic terpene synthases in the Tps-b terpene synthase family". Evolution. 67 (4): 1026–1040. doi:10.1111/evo.12013. PMID 23550753. S2CID 29434246.
11. Zhang, R; Sharkey, TD. (2009). "Photosynthetic electron transport and proton flux under moderate heat stress". Photosynthesis Research. 100 (1): 29–43. doi:10.1007/s11120-009-9420-8. PMID 19343531. S2CID 11956742.