School of Biological Sciences

Asaph Cousins

Name: Asaph Cousins
Field of Study: Plant Metabolism and Physiology
Title: Associate Professor
Degrees: Ph.D., Plant Biology, Arizona State University
Homepage: Click
Office: 406 BA Abelson Hall
Phone: 509-335-7218; Lab 509-335-8243
Fax: 509-335-3184
Mailing Address: School of Biological Sciences
Washington State University
PO Box 644236
Pullman, WA 99164-4236

Research Interests

The ability to monitor and predict how plants both influence and are influenced by future climatic conditions is critical for the health of our planet and for future food production. My research couples molecular biology techniques with plant physiology and mathematical modeling of photosynthesis to understand the mechanistic processes dictating plant-environment interactions.  This research uses a variety of experimental techniques, including field experiments, leaf and whole plant gas exchange, recombinant DNA techniques, biochemistry, and metabolite analysis to elucidate how the interactions of plant light utilization, carbon and nutrient assimilation, and isotope discrimination are influenced by changing environmental conditions. 

The two main areas my research is focusing on are:

1)   Plant energy metabolism

Understanding the flow of energy between metabolic pathways and organelles is important for determining how plants will respond to environmental stress and future climatic conditions.  This research uses gas exchange, mass spectrometry and metabolite analysis to understand the key steps in photosynthesis, photorespiration and nitrogen metabolism that coordinate the energy flow between these competing processes.

2)   Carbon and oxygen isotope exchange in plants

Isotope analysis of atmospheric CO2 is an important tool for monitoring ecosystem changes in plant metabolism in response to climate change.  However, to interpret the atmospheric CO2 isotopic signature requires an understanding of the fractionation steps associated with specific processes during leaf gas exchange. This research uses molecular tools coupled with stable isotope analysis and mathematical modeling of photosynthesis and isotope exchange to understand how leaf metabolism and anatomy influence the exchange of carbon and water between plants and their environment.

I am excited to discuss student research opportunities and will be accepting graduate students in the Spring of 2008.  Please contact me at if you are interested in joining the lab.

Representative Publications

Gandin A., Koteeva N., Voznesenskaya E., Edwards G. Cousins A.B. (2014) Temperature response of the  photosynthetic machinery in the C3-C4 intermediate Salsola divaricatePlant Cell and Environment In press


von Caemmerer S., Edwards G.E., Koteyeva N., Cousins A.B. (2014) Single Cell C4 photosynthesis in aquatic and terrestrial plants: a gas exchange perspective Journal of Aquatic Botany In press


Gandin A., Denysyuk M., Cousins A.B. (2014) Disruption of the mitochondrial alternative oxidase (AOX) and uncoupling protein (UCP) alter rates of foliar nitrate and carbon assimilation in Arabidopsis thalianaJournal of Experimental Botany DOI:10.1093/jxb/eru158


von Caemmerer S., Ghannoum O., Cousins A.B. (2014) Carbon isotope discrimination as a tool to explore C4 photosynthesis Journal of Experimental Botany DOI:10.1093/jxb/eru127


Kromdijk J., Ubierna N., Cousins A.B. Griffiths H. (2014) Bundle sheath leakiness in C4 photosynthesis: a careful balancing act between CO2 concentration and assimilation. Journal of Experimental Botany        DOI:10.1093/jxb/eru157


Studer A., Gandin A., Kolbe A., Cousins A.B. Brutnell T. (2014) Carbonic anhydrase does not limit photosynthesis in Zea mays under current atmospheric CO2 conditions Plant Physiology     DOI:10.1104/pp.114.237602


Walker B., Strand D.S., Kramer D.M., Cousins A.B. (2014) The Response of Cyclic Electron Flow around Photosystem I to Changes in Photorespiration and Nitrate Assimilation Plant Physiology    165:453-462


Cousins A.B., Johnson M., Leakey A.D.B (2014) Photosynthesis and the environment. Photosynthesis       Research 119:1–2


Sun W., Ubierna N., Ma J.Y., Walker B., Kramer D., Cousins A.B. (2014) The coordination of C4 photosynthesis and the CO2 concentrating mechanism in Zea mays and Miscanthus× giganteus in             response to transient changes in light quality. Plant Physiology 164:1283-92


Stutz S.S., Edwards G.E., Cousins A.B. (2014) Singlecell C4 photosynthesis: efficiency and acclimation of Bienertia sinuspersici to growth under low light New Phytologist 202:220-32

School of Biological Sciences, Washington State University, PO Box 644236, Pullman WA 99164-4236, 509-335-3553, Contact Us
The SBS main office is located in 312 Abelson Hall on the Pullman campus.