Reactive oxygen species (ROS) control many different processes in cells including cell death, stress responses, aging and cancer. Because the potential risk of oxidative stress is common to all aerobic organisms, elucidating the ROS-signaling network of plant cells would have a significant impact in medicine and agriculture. The long-term goal of the project is to dissect the ROS signaling network of cells and determine how ROS signals are sensed and transduced in plant cells. The experimental approach employed in the program will be to use a combination of genetic, molecular, biochemical and bioinformatic research tools to identify, clone and characterize different genes involved in ROS signaling in cells. The identification of genes involved in ROS sensing, the pathway for ROS signaling, and the collection of ROS-mutants, generated during the course of the proposed research, would serve as a valuable resource for the entire scientific community. The information generated from the project will enhance overall understanding of plant biology, and help determine to what extent and in what manner ROS are involved in different biological process. Broader impacts. To increase interest and understanding of science in young people, high school students and undergraduates, including minorities, will be recruited into the project and trained in ROS biology, molecular biology, and bioinformatics. This project will provide training to 2 graduate students, 8 undergraduates and 8 high school students. In addition, four 1 week summer workshops, 25 high school students each, are planned for the duration of the grant. The proposed project will provide interdisciplinary training that has become imperative for success in plant sciences. To enhance the awareness of high school students, teachers and undergraduates, two teaching-oriented websites targeted to high school students and undergraduates, and an online presentation targeted to high school teachers will be developed to share knowledge and enhance awareness to ROS metabolism in plants, mammals and other organisms.
The two major outcomes of the project are: 1. The discovery that plants can send a signal from a small group of cells located in a particular tissue to the entire plant at a very fast rate (about 8.5 cm or 3.4 inch per minute). The signal initiates as a burst of synthesis of a reactive oxygen molecule and each cell along the path of the signal is triggered to initiate the synthesis of this molecule resulting in a wave of reactive oxygen production that propagates throughout the entire plant. Once this reactive oxygen species (ROS) wave reach the different tissues of the plant it induces a heightened state of resistance in these tissues to different environmental stresses or insects. Please see picture showing on the left the imaging of the signal initiating from the point of origin (indicated by a white arrow) and spreading within 10 minutes to the entire plant. On the right side of the picture a model is shown to describe how the signal propagates. Each cell along the path of the signal participates in the response and generates ROS resulting in the formation of the ROS wave. The discovery of this rapid systemic signaling pathway could have a significant impact on the development of crops with enhanced tolerance to drought, heat and other environmental stresses. Miller et al., (2009) Science Signaling. 18;2(84):ra45; Mittler et al., (2011) Trends Plant Sci. 16(6):300-9; Suzuki et al., (2013) Cell Reports. Submitted. 2. The discovery that plants have a backup system to protect themselves from the toxic effects of reactive oxygen species (ROS). This backup system is activated in plants that lack more than one defense mechanism against ROS and involves proteins and enzymes that function to suppress cell death, repair DNA damage and regulate cell cycle. The discovery of this backup system can have a significant impact on agriculture and medicine providing new and novel pathways to combat the toxic effects of ROS and their involvement in different stresses and disease such as cancer. Vanderauwera et al., (2011) Proc Natl Acad Sci U S A. 108(4):1711-6. The project provided training to 7 high school students, 8 undergraduate students, 2 graduate students and one post doctoral student (including minorities). The project website is: http://biology.unt.edu/ros/ Thank you for your support!