Ozone Stress Response in Northern Red Oak Trees

Northern Red Oaks (Quercus rubra L.) are ecological and economically important hardwood trees found in North America. These trees provide nesting sites for multiple organisms and are used for flooring, furniture, and pulpwood. The increase of exotic pests and diseases, combined with climate change, threaten the sustainability and regeneration of oaks. In the United States, ozone is responsible for approximately $500 million in reduced crop production each year. Ozone pollution places environmental stress on trees resulting in early leaf aging and loss of photosynthetic capacity.  Currently, genetic databases are limited in providing the genomic resources to improve the sustainability of hardwood trees.  To help solve this problem, undergraduate students from a minority serving university were trained for ten weeks at a research-one institution funded by the National Science Foundation.  The focus of this study was to identify and examine the genes responsible for environmental stress responses in red oak seedlings when exposed to 30 days of ozone concentrations (150, 225, and 300 parts per billion) in greenhouses.   Leaf tissue of the control and ozone-treated red oak seedlings were harvested and genetic material was isolated after the exposure period.  To identify the plants’ full genome, 454 sequencing technology was used.  Cytoscape programming indicated genetic locations of ozone stress responses in various plant cell structures. Results showed that specific stress genes were activated as ozone concentrations increased. The results of this project are significant in helping the scientific community use innovative genetic tools to overcome environmental stresses that are threatening our forests.