Many organisms rely on hormone signaling networks to control growth, development, and responses to their environment. In this project a systems biology approach will be used to reveal the Arabidopsis thaliana gene expression networks that control plant developmental changes mediated by ethylene, a gaseous plant hormone. Ethylene has important roles in modulating plant growth in stressful environments, as well as during fruit ripening. This project will provide insight into the hormonal controls of root development thereby having important agricultural implications, as root architecture determines the efficiency of moisture and nutrient uptake from soil. The molecular biology and modeling approaches developed in this project can be applied to other signaling networks and plant species. In terms of broader impacts, undergraduate and graduate student researchers will receive training at the interface of biochemistry, genetics, mathematics, and computer science. The project will support and expand an on-going service-learning program where undergraduate biology laboratory students teach middle and high school students through an active learning exercise on Mendelian and molecular genetics using plants with defects in ethylene signaling.
The goal of this project is to uncover the transcriptional networks downstream of the ethylene receptors that control multiple root ethylene responses in Arabidopsis thaliana using null mutants of ethylene receptors. An ethylene-regulated, genome-wide data set measuring temporal changes in transcript abundance in root samples will be utilized to identify sequentially induced sets of transcripts encoding transcription factors involved in root developmental processes. Bayesian modeling will be utilized to identify patterns and temporal relationships to predict transcriptional networks, which will be validated using genetic approaches, in an iterative fashion. Binding sites of ethylene-regulated transcription factors will be identified by computational and experimental approaches. The broader impacts include both student research training and a service-learning project with the goal of engaging non-major undergraduates in science through teaching high school students. This project will support the coordination and organization of school visits, assessment of learning outcomes for undergraduates, and dissemination of this program to other academic institutions.
