CAREER: microRNA Regulation of Spatial Gene Expression During Symbiotic Nodule Development

South Dakota State University, Brookings SD

Investigators

Abstract

Global nitrogen needs are likely to be met through a combination of chemical fertilizers and cultivation-induced biological nitrogen fixation (BNF). The majority of cultivation-induced BNF occurs in symbiotic nodules of legumes such as soybean. Understanding the development of symbiotic nodules and enhancing biological nitrogen fixation would help reduce chemical fertilizer usage, and provide a sustainable supply of clean water, fertile land and a benefiting habitat for future generations, an immense benefit to the society. This project will provide research training for three graduate students and multiple undergraduate students in plant biology. Undergraduate and graduate exercises in bioinformatics will be developed using data from the project and disseminated for use by other educators. Results from the project will be disseminated through a project website, public databases, and relevant biological repositories. "Rhizodive", a statewide integrated research and training pipeline involving high school students, teachers, and university students to examine rhizobial diversity using trap legumes will be executed (with targeted recruitment of schools with significant minority enrollment). These activities will cultivate and promote scientific interest among the younger generation, promote participation of minorities in STEM areas, help develop a competitive STEM workforce, and enhance STEM curriculum and educators. This project will utilize novel genomics-empowered approaches to discover molecular signaling mechanisms that regulate legume nodule development. Based on evidence from gene expression, microRNA sensor and suppression assays, one emerging hypothesis is that microRNAs are one of the crucial determinants of the development of different nodule zones. The project will test this hypothesis utilizing a combination of genetic, molecular and micro-imaging approaches. Specifically the results from the project will help identify early signaling pathways that cause distinct development of different nodule zones. This knowledge in combination with other advances in plant breeding and biotechnology will enable the optimization of BNF (or possibly transfer it to non-legume crops) thus helping to meet global N needs in a sustainable manner. This is especially relevant in the context of a growing world population (expected to reach 8-11 billion by 2050), reduction in cultivable area due to urbanization, and the essential nature of nitrogen in maintaining plant productivity.