OXI1 signal transduction

A number of reactive oxygen species (ROS) are continuously produced in plants as byproducts of aerobic metabolism. Depending on the nature of the species, different ROS are highly toxic and rapidly detoxified by various cellular enzymatic and nonenzymatic mechanisms. Whereas plants try to combat increased ROS levels during abiotic stress conditions, plants seem to generate ROS willingly as signaling molecules to control various processes including pathogen defense, programmed cell death and stomatal behavior. Recent biochemical and genetic evidence from my lab indicates that a specific protein kinase termed OXI1 and two MAPKs are involved in ROS signal transduction in Arabidopsis. As part of this research proposal we will attempt to i) investigate the function of OXI1 in the context of the ROS-activated MAPK signal transduction pathway, ii) identify the component(s) of the ROS-activated MAPK pathway that interact with OXI1 and iii) determine the function of these components in a physiological context.

To resist colonization by mircobial pathogens, plants have evolved a number of sophisticated defense mechanisms. Following pathogen recognition, one of the immediate defense responses is the production of reactive oxygen species (ROS) at the site of infection. However, besides playing an important role in disease, ROS are also involved in physiological and developmental processes. Using a combination of genetic and biochemical techniques, the function of ROS was studied in the context of defense signaling. In the framework of this project, a number of novel components could be identified and integrated into the complex network of signalling reactions during plant defence. These findings will contribute to our current understanding of disease and immunity of plants and should result in important applications for achieving a sustainable agriculture.