Research

Research Priorities: Photoprotection during photosynthesis, ecophysiology of plants, carotinoid function, xanthophyll cycle

Barbara Demmig-Adams examines fundamental questions of plant physiology. Her profound investigations of the mechanisms with which plants protect themselves from too much sunlight under varying environmental conditions are considered milestones of modern plant biology.

Plants have developed different strategies to protect themselves from too much sunlight. One of those strategies involves converting excess radiation energy into heat in a controlled manner, thereby removing it from the system. Zeaxanthin, an orangey pigment from the group of xanthophylls, plays an important role in this strategy. Barbara Demmig-Adams was able to show this using the example of the balsam poplar (Populus balsamifera L.), common ivy (Hedera helix L.) and the split-leaf philodendron (Monstera deliciosa Liebm.). She found that when there is strong light, zeaxanthin collects in the leaves and more heat is simultaneously expelled. By contrast, when the light becomes weaker, the relative amount of the precursor molecule violaxanthin increases. From this, Demmig-Adams concluded that plants use the so-called xanthophyll cycle to dispense with excess energy before their photosynthesis systems are irreparably damaged. Her 1987 article “Photoinhibition and Zeaxanthin Formation in Intact Leaves” was honoured as a “milestone” of modern plant biology by the journal "Plant Physiology" in 2010.

Demmig-Adams’ studies on the molecular mechanisms of plant photoprotection and photoinhibition, i.e. for limiting photosynthesis when light intensity exceeds the point of light saturation, are also of great relevance when it comes to the agricultural and technical uses of plants. During her work into the differences in photoprotection between different plants and under different environmental conditions, Demmig-Adams continually broadened her perspective. She discovered parallels between plants’ photoprotection and the mechanisms with which the human eye shields itself from damage due to excessive light intensity. Here, too, zeaxanthin and the orange-coloured pigment lutein, which collect in the “yellow spot” on the macula (Macula lutea), play a pivotal role. The substantial difference is that humans, unlike plants, cannot synthesise these pigments themselves, but must instead absorb them nutritionally. Even though these complex processes are not yet fully understood, nutritional advice can still be derived from them, e.g. for preventing eye diseases such as age-related macular degeneration (AMD).

In addition to her work as a researcher, Barbara Demmig-Adams advocates for innovative teaching and learning methods. She pursues this, for example, as a part of the “Science Education Initiative” and the “Center for STEM Learning (CSL)” at the University of Colorado.

Career

• since 2013 Professor of Distinction, University of Colorado, Boulder, USA
• since 1998 Professor, Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA
• 1994-1998 Associate Professor, Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA
• 1994 Visiting Fellow, Research School of Biological Sciences, Australian National University, Canberra, Australia
• 1990-1994 Assistant Professor, Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA
• 1989-1990 Research Associate, Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA
• 1989 Habilitation, Julius-Maximilians-Universität of Würzburg, Würzburg, Germany
• 1986-1989 Research Stay, Julius-Maximilians-Universität of Würzburg, Würzburg, Germany
• 1985-1986 Postdoc Scholarship, Carnegie Corporation of New York, New York, USA
• 1985 Postdoc Scholarship, McKnight Foundation, Minneapolis, USA
• 1984-1986 Postdoctoral Fellow, Department of Plant Biology, Carnegie Institution of Washington, Stanford, USA
• 1984 PhD in Plant Physiology, Julius-Maximilians-Universität of Würzburg, Würzburg, Germany
• 1974-1979 Degree in Biology and Chemistry (State Examination), Julius-Maximilians-Universität of Würzburg, Würzburg, Germany

Functions

• Affiliate, Renewable and Sustainable Energy Institute, University of Colorado, Boulder, USA
• Faculty Mentor for the Interdisciplinary Quantitative Biology (IQ-Biology) Program, BioFrontiers Institute, University of Colorado, Boulder, USA
• Member, College of Arts & Sciences Honors Council, University of Colorado, Boulder, USA

Projects

• 2013-2014 Subproject “Assessing the Impact of Early, Individualized Faculty and TA Interventions for At-Risk Students”, Award “Towards a Center for STEM Education”, National Science Foundation (NSF), USA
• 2011-2015 “Increasing Teaching Effectiveness in Ecology and Evolutionary Biology”, Science Education Initiative, University of Colorado, Boulder, USA
• 2011-2013 “Assessing Functional Diversity of Algal Communities at the Single Cell Level with a Compact Multi-function Microfluidic Cytometer”, NSF, USA
• 2011-2013 “Developing a Roadmap to the Diatoms with Greatest Oil Production”, VCR Innovative Seed Program, University of Colorado, Boulder, USA
• 2011-2012 “Extractive Photobioreactor”, ConocoPhillips Company, Houston, USA
• 2010-2015 “Collaborative Research (Arabidopsis 2010): Ecological Genomics of Adaptation to the Environment”, NSF, USA
• 2010-2013 “Novel Genetic Dissection of Temperature Tolerance in the Model Plant Arabidopsis”, VCR Innovative Seed Program, University of Colorado, Boulder, USA
• 2009-2013 “Photosynthesis and Phloem Anatomy”, NSF, USA
• 2009-2010 “Optimization of Light Use Efficiency for Algal Production of Glycerol as a Precursor for Transport Fuels”, ConocoPhillips Company, Houston, USA
• 2007-2010 “Defining a Mechanistic Link Between Stand Thinning, Drought Stress, and Risk of Mortality from Pine Bark Beetles in Californian Yellow Pine”, U.S. Department of Agriculture, USA
• 2007-2008 “Identification of Novel Biomolecules for Improved Biological Production of Alternative Fuels from Solar Energy”, Energy Initiative, NREL Seed Grant Program, University of Colorado, Boulder, USA
• 2007-2008 “Towards the Establishment of a Novel Role of the Carotenoid Zeaxanthin in Signaling”, Council on Research and Creative Work (CRCW), University of Colorado, Boulder, USA
• 2003-2007 “Photosynthetic Acclimation, Photoprotection, and Phloem Loading”, NSF, USA
• 2002-2005 “Seasonal Changes in the Productivity of Evergreen Forests: Toward an Understanding of what it Takes to be ‘Evergreen’ and How Seasonal Changes are Orchestrated”, Andrew W. Mellon Foundation, New York City, USA
• 2000-2003 “Protein Phosphorylation and Xanthophyll Cycle Dynamics dependent on Lifeform”, U.S. Department of Agriculture, USA
• 1999-2001 “Protein Phosphorylation and Photoprotection during Winter Stress”, NSF, USA
• 1996-1998 “Photoprotection during Winter Stress”, NSF, USA
• 1994-1999 “Biosphere/Atmosphere Interactions: Biochemical Causes to Global Implications”, NSF, USA
• 1994-1997 “Interaction of Photoprotective Processes in Plants”, U.S. Department of Agriculture, USA
• 1992-1995 “Carotenoids and Photoprotection in CAM Plants”, NSF, USA
• 1992-1993 “The Relative Roles of Photoprotective Energy Dissipation and Repair Processes in Plants under High Light Stress”, CRCW, University of Colorado, Boulder, USA
• 1991-1992 “Remote Sensing of Actual Photosynthesis Rates of Vegetation under Changing Environmental Conditions”, Global Change & Environmental Quality Program, University of Colorado, Boulder, USA
• 1990-1992 “Carotenoids and Photoprotection in Various Crop Species”, U.S. Department of Agriculture, USA

Honours and Memberships

• 2016 College Scholar Award, University of Colorado, Boulder, USA
• 2014 Marinus Smith Award, Parents Association for services to undergraduates, University of Colorado, Boulder, USA
• 2013 Chancellor’s Award for Excellence in STEM education, University of Colorado, Boulder, USA
• 2011 Boulder Faculty Assembly Excellence in Teaching Award, University of Colorado, Boulder, USA
• since 2011 Member, German National Academy of Sciences Leopoldina, Germany
• 2008 Certificate of Appreciation for work with students with disabilities from Disabilities Services, University of Colorado, Boulder, USA
• 2006 The Boulder Faculty Assembly Excellence in Research, Scholarly, and Creative Work Award, University of Colorado, Boulder, USA
• 1997 Faculty Fellowship, Council on Research and Creative Work (CRCW), University of Colorado, Boulder, USA
• 1992-1997 Fellowship in Science and Engineering, David and Lucile Packard Foundation, Los Altos, USA
• 1987 Prize for Biology, Göttingen Academy of Sciences and Humanities, Göttingen, Germany