Ruth Alscher, of the Department of Plant Pathology, Physiology and Weed Science at Virginia Polytechnic and State University is applying to spend a year at the DOE/MSU Plant Research Laboratory on the Michigan State University campus in the laboratory of Dr. Chris Somerville. The title of her research project will be Molecular bases of antioxidant responses in Arabidopsis. The mechanisms in green leaf cells which protect against oxidative stress will be studied in Arabidopsis, in particular the production of three plastid proteins specifically associated with resistance whose inheritance may be coordinately controlled. These antioxidant defense proteins have been implicated in resistance to a number of different stresses, including drought, extremes of temperature, herbicides and air pollutants. The PI will avail herself of the expertise and resources of Dr. Sommerville's laboratory to study effects of exposure to stress on gene expression, to identify mutants with a altered sensitivity to oxidative stress and to study the signalling process by which altered gene expressioning is brought about. One principal focus will be the development of a molecular cloning strategy to identify the genes which encode the antioxidant plastid proteins. A year of concentration in the molecular aspects of stress responses in green plant cells will enable the PI to progress towards her goal of understanding the basis in molecular genetics of differential resistance to oxidative stress in photosynthetic tissue.