Functional analysis of the FIERY1 Signaling Network

Donald Danforth Plant Science Center, Saint Louis MO

Investigators

Abstract

Drought, extreme temperatures, and high soil salinity are common adverse environmental conditions that can greatly impair crop productivity. Understanding how plants sense and respond to these abiotic stresses will help in the breeding or engineering of a new generation of stress-tolerant crop plants. One early response of plants to abiotic stress is the activation of stress-responsive genes. The products of these genes can collectively enhance plant stress tolerance. To find out how the expression of these genes is regulated, genetic studies were conducted with the model plant Arabidopsis. The FIERY1 gene was identified in these studies as a negative regulator of stress gene expression. It is also required for tolerance to chilling, freezing, and salt stresses. However, the FIERY1 protein is very complex in that it possesses both an inositol polyphosphate 1-phosphatase activity and a bisphosphate nucleotidase activity in vitro; these activities and their role in signal transduction are unclear. The current study will 1) define the cellular functions of FIERY1 using a combination of cell biology, molecular biology, biochemistry and physiological approaches; and 2) result in the isolation of signaling components in the FIERY1 network that mediate phytohormone signaling and plant developmental adaptations to stress. This project will yield insights into important cell-signaling processes that regulate plant development and response to the environment. The study may also define better strategies to engineer crop plants for enhanced tolerance to adverse environmental conditions. Broader Impacts The FIERY1 gene is widely conserved in organisms. The human homolog of FIERY1 is thought to be a therapeutic target of lithium treatment for bipolar disease, which seriously affects about one percent of the U.S. population. Thus, understanding the function of FIERY1 in plants has implications for the identification of new therapeutic targets for treating depression in humans. Concerning human resources, the PI will support public education activities that are regularly held at the Danforth Center. Undergraduate and high school students will also participate in the study. These outreach activities will help the public to appreciate the importance of plant biology research to agriculture in the U.S. and throughout the world.