Poster: Global Change

Abs # 70: Gene expression patterns of trembling aspen trees following long-term exposure to elevated CO2 and tropospheric O3

Presenter:	Sharma, Pooja , psharma@mtu.edu
Authors	Sharma, Pooja  (A)   Karnosky, David  (A)   Dupleiss, Sebastein  (B)   Podila, Gopi  (C)   Martin, Francis  (B)
Affiliations:	(A): Michigan Technological University (B): INRA Nancy France (C): University Of Huntsville, Alabama

Global increase in air pollutants is one of the major threats to the functioning, structure and diversity of natural and seminatural ecosystems. Concentrations of the green house gases carbon dioxide (CO2) and ozone (O3) are increasing rapidly. Elevated atmospheric CO2 in short-term exposures is known to increase photosynthesis, delays foliar senescence in autumn, and stimulates aboveground and belowground growth. Ozone enters mesophyll tissue through stomata and produces free hydroxyl radicles (OH), superoxide anion (O2) and hydrogen peroxide (H2O2). This results in peroxidation and denaturation of cellular membranes leading to in accelerated premature senescence by , induction of ethylene, and changes in specific mRNA resulting in decreased growth and development. These reactive oxygen species (ROS) are scavenged at different subcellular compartments by antioxidant enzymes. Therefore plants undergo numerous adjustments to counteract the effects of stress by regulating a number of genes play in a role in stress responses. In the future, elevated tropospheric ozone will not occur alone but rather in combination with elevated atmospheric CO2. The main goal of this research project was to study patterns of global gene expression using high density arrays and to see if we could detect any linkages between gene expression and physiological responses following long term exposure to elevated CO2 and tropospheric O3. The present study is one of the first of its nature to study global gene expression on a forest ecosystem and also to study interacting effects of ozone and carbon-dioxide.