Intellectual Merit: The ability to respond to fluctuations in nutritional availability is critical for all living cells. Multicellular organisms can respond to such challenges by altering a number of physiological, developmental and molecular processes that are often controlled at the level of transcription. While conventional molecular biology and physiological approaches have revealed the importance of genes involved in nutrient uptake and transport, few transcriptional regulators have been identified that coordinate organismal responses to nutrient availability. This research focuses on the following questions: What transcription factors regulate the response to iron deprivation in plants? How do these transcription factors interact with each other and other proteins to regulate gene expression? Is there a protein complex that acts as an iron sensing mechanism in plant roots that reacts and leads to the classic response to low iron? Since plant iron transporters translocate other metals nonspecifically, studying this mechanism will further inform us about homeostasis of other metals. Moreover, the protein-protein interactions that we will examine shares features with an iron sensing and response mechanism recently described in mammalian cells and would, therefore, shed new light on conserved iron sensing and response mechanisms.
Broader Impacts: Iron deficiency, which causes anemia, is the most prevalent nutritional disorder in the world. Approximately 30% of the world's population is iron deficient, which results in increased maternal mortality and infant loss, impaired growth and cognitive development and decreased immune response. In addition, iron deficiency is a global problem for the growth of major crops grown in calcareous soils. This project proposes to increase our understanding of how plants respond to iron deprivation with the long term goal of producing plants with enhanced nutritional capacity and tolerance of nutrient-poor soils, thus increasing our ability to address increasing global nutritional needs. In addition to agricultural and nutritional contributions, this project will create resources for the scientific community at large, including a new model for how iron content is sensed within cells. Moreover, the project will provide unique research opportunities for students, in particular, underrepresented minority groups attending smaller historically black colleges and universities. Thus, the project will help to increase the dept and breath of molecular and plant biology researchers.
