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Thomas D. Sharkey

Professor of Botany

Ph.D. (1980) Michigan State University

Office: B214 Birge Hall

Plant-atmosphere interactions; isoprene emission; photosynthesis, especially carbon metabolism; plant biochemistry and biophysics


Laboratory Webpage




Members of my laboratory work in two areas, isoprene emission from plants or carbon metabolism of photosynthesis.  Work is carried out at the biochemical and molecular level. 

Current photosynthesis research is focused on the export of carbon from chloroplasts at night.  Starch builds up in chloroplasts during the day and is broken down at night.  The biochemical pathway involved is one of the last big uncertainties in photosynthetic carbon metabolism.  Using NMR we have shown that the carbon is never broken down to the level of triose phosphate but remains at the level of a hexose or larger.  We have developed a glucose cycle hypothesis to explain how starch breakdown occurs and are now carrying out the molecular and biochemical studies to test how important this cycle is during starch breakdown.  

Isoprene is emitted from many flowering plants.  Isoprene protects photosynthesis from high temperature.  Plants given isoprene at physiological concentration have substantially more recovery of photosynthetic rate following a two-minute treatment at 46C than plants in which isoprene production has been suppressed by feeding the inhibitor fosmidomycin.  This experiment is conclusive evidence for the role of isoprene in protecting against short episodes of heat stress.  Molecules similar to isoprene can mimic the effects of isoprene if they have double bonds (alkenes) but not if they lack double bonds (alkanes).   Isoprene synthesis is regulated at many different levels and projects are under way to sort out the molecular and protein level regulation mechanisms.

Recent Publications


T.D. Sharkey, E.A. Holland, H.A. Mooney eds, Trace Gas Emissions from Plants, Academic Press, San Diego, 1991

R.C. Leegood, T.D. Sharkey, and S, von Caemmerer eds Advances in Photosynthesis: Physiology and Metabolism, Kluwer Academic Publishers, Dordrecht 2000

Jounal Papers

Singsaas, E.L. and T.D. Sharkey (in press) The effects of high temperature on isoprene synthesis in oak leaves.  Plant, Cell and Environment

Sharkey,T.D. (2000) Perspectives: Plant Science - Some like it hot.  Science 287:435-437

Sharkey,T.D., E.L. Singsaas, M. T. Lerdau, and C. Geron. (1999) Effects of weather on the capacity for isoprene emission and applications in emissions modeling.  Ecological Applications 9:1132-1137

Hanson, D. T., S. Swanson, L.K. Graham, and T.D. Sharkey.  Evolutionary significance of isoprene emission from mosses. American Journal of Botany 86: 634-639

Singsaas,E.L. and T.D. Sharkey. (1998) The regulation of isoprene emission responses to rapid leaf temperature fluctuations. Plant Cell & Environment 21:1181-1188

Schleucher,J., P.J. Vanderveer, and T.D. Sharkey. (1998) Export of carbon from chloroplasts at night.  Plant Physiology 118:1439-1445

Galston, A.W. and T.D. Sharkey. (1998) Frits Warmolt Went: A biographical memoir. Biographical Memoirs, National Academy Press 74:1-17

Laporte, M.M., J.A. Galagan, J.A. Shapiro, M.R. Boersig, C.K. Shewmaker, and T.D. Sharkey.  (1997) Sucrose-phosphate synthase activity and yield analysis of tomato plants transformed with maize sucrose-phosphate synthase.  Planta 202:253-259

Singsaas, E.L. M. Lerdau, K. Winter, and T.D. Sharkey.  (1997) Isoprene confers thermotolerance to isoprene emitting plants.  Plant Physiology 115: 1413-1420

Loreto, F., P. Cicciolo, E. Brancaleoni, A. Cecinato, M. Frattoni, and T.D. Sharkey (1996)  Different sources of reduced carbon contribute to form three classes of terpenoid emitted by Quercus ilex L. leaves.  Proceedings of the National Academy of Science 93:9966-9969

Sharkey, T.D.  (1996) Isoprene synthesis in plants and animals.  Endeavor 20:74-78

Sharkey, T.D. and E.L. Singsaas.  (1995) Why plants emit isoprene. Nature 374:769

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2000 University of Wisconsin Department of Botany
Last updated: 19 November 2000