Collaborative Research: Regulation of CpNifS/CpSufE1-Mediated Iron-Sulfur Cluster Synthesis in Plant Plastids. Implications for Sulfur and Iron Metabolism and Selenium Tolerance

Coastal Carolina University, Conway SC

Investigators

Abstract

Intellectual Merit: Photosynthesis, the production of sugars from water and carbon dioxide, takes place in plant chloroplasts and drives all life on our planet. The chloroplasts are also needed for the production of the oxygen that we breathe, and additionally make nitrogen and sulfur compounds necessary for plant growth and a healthy plant-based diet. Iron deficiency limits plant growth because iron is available only at very low levels in soils and iron is essential for photosynthesis. Photosynthesis requires numerous proteins, many of which are dependent upon iron-sulfur clusters for proper protein function. This project aims to study how the machinery that assembles iron-sulfur clusters in chloroplasts is regulated. The integration of (1) sulfur and iron metabolism and their regulation and (2) iron-sulfur cluster assembly will get special attention in this project. The regulatory roles of plant-specific proteins that function in iron-sulfur cluster assembly will be delineated. This collaborative research additionally seeks to explore how selenium, which is similar to sulfur yet toxic, interferes with essential sulfur metabolism in chloroplasts. Moreover, the role of specific iron-sulfur cluster-related proteins in selenium metabolism will be analyzed. An interdisciplinary approach involving a combination of biochemistry, genetics and plant physiology in the model plant Arabidopsis will be employed. New analysis methods for the assembly of iron-sulfur clusters in vivo will be developed. These collaborative studies will provide much-needed insights into the mechanisms and regulation of assembly of the photosynthetic machinery in plants. Broader impacts: This research involves collaboration between Coastal Carolina University, a primarily undergraduate institution with 18% minority enrollment, and Colorado State University. The project will train several undergraduate students, a graduate student, and a post-doctoral fellow. Undergraduate students at CCU will be engaged and trained in cutting edge research methods. The project directly involves students in a larger undergraduate course in the excitement of hypothesis-driven research in a unique and innovative part of the project, which integrates classroom teaching and research, thereby increasing scientific understanding of a large group of students. Iron is limiting to crop growth in many environments; selenium contamination is increasingly problematic. Therefore, the results of the collaborative project will also have direct implications for agriculture, biomass production, the production of fortified foods, and the environment.