My laboratory applies physiological, biochemical and molecular biological approaches to study metabolism, nutrition, and physiology in plants. An integrative approach is taken whereby processes are studied at the whole plant, cell, organelle and molecular level. Nicotiana tabacum and Arabidopsis thaliana are used as model plant species for these studies. Interests include mitochondrial electron transport and the alternative oxidase; respiratory carbon metabolism; nitrogen and phosphorus nutrition; environmental and stress physiology; plant responses to climate change; mitochondrial stress responses; oxidative stress; anaerobic metabolism; plant cell death mechanisms; terminal respiratory oxidases in cyanobacteria and marine invertebrates; plant-pathogen interactions; and comparative approaches to cellular energetics.
Research Area: Plant Biology, Biochemistry, Cell and Molecular Biology, Physiology
Respiration is a central component of carbon and energy metabolism and thus an important determining factor for plant growth and productivity. Nonetheless, the pathways of both respiratory carbon metabolism and mitochondrial electron transport in plants have components that reduce the energy yield of respiration. It has been proposed that such gratuitous disposal of resources may have adaptive value, particularly under unfavorable (stress) conditions. My research focuses on a unique component of the plant mitochondrial electron transport chain called alternative oxidase (AOX). AOX catalyzes the oxidation of ubiquinol, reducing O2 to H2O. However, electron flow from ubiquinol to AOX is not coupled to the generation of proton motive force and is thus a non-energy-conserving branch of the electron transport chain, bypassing two sites of energy conservation associated with the cytochrome pathway. My current research program is aimed at understanding 1.) the biochemical and molecular mechanisms that control rates of AOX respiration and 2.) the role of this non-energy conserving pathway in cellular metabolism and physiology, particularly during periods of biotic and abiotic stress.