ABSTRACT
Oxygen in the atmosphere and water supports aerobic life. Plants consume oxygen during respiration and generate it by photosynthesis. During these metabolic processes, the production of reactive oxygen species (ROS) cannot be avoided in plants especially in organelles such as chloroplasts, mitochondria and peroxisomes. The reactive nature of ROS led to the evolution of ROS scavenging mechanisms for protection. It is widely accepted that ROS play an important role in the ability of plants to
University of Illinois at Urbana-Champaign, Institute for Genomic Biology, 1206 W. Gregory Dr. Urbana, IL 61801, Fax: +1 (217) 244 20 57, E-mail: ddbilgin@illinois.edu
adapt to environmental conditions and respond to various stresses (Scheel 2002, Apel and Hirt 2004, Foyer and Noctor 2005, Torres and Dangl 2005, Gechev et al. 2006, Pitzschke et al. 2006, Gadjev et al. 2008, Shetty et al. 2008). ROS, which under normal conditions, are produced and scavenged in a controlled manner, become in excess under stress. Overproduction of ROS is a key part of the defense mechanism against pathogens and induces defense-related gene expression. The distinct role of ROS as a signaling molecule is important for both plant development and defense.
