Ethylene Signaling and Transcriptional Networks that Control Root Development

许多生物体依靠激素信号网络来控制生长、发育和对环境的反应。在这个项目中，系统生物学的方法将被用来揭示拟南芥基因表达网络，控制植物发育变化由乙烯介导，一种气态植物激素。乙烯在逆境环境下调控植物生长和果实成熟过程中具有重要作用。该项目将深入了解根系发育的激素控制，从而具有重要的农业意义，因为根系结构决定了从土壤中吸收水分和养分的效率。本项目开发的分子生物学和建模方法可以应用于其他信号网络和植物物种。就更广泛的影响而言，本科生和研究生的研究人员将在生物化学、遗传学、数学和计算机科学的界面上接受培训。该项目将支持并扩展一项正在进行的服务学习计划，在该计划中，生物实验室的本科生将通过孟德尔和分子遗传学的积极学习练习，利用乙烯信号缺陷的植物来教授初高中学生。本项目的目标是利用乙烯受体的零突变体揭示控制拟南芥多个根乙烯反应的乙烯受体下游的转录网络。一个乙烯调控的全基因组数据集测量了根样品中转录物丰度的时间变化，将用于鉴定顺序诱导的转录物集，编码参与根发育过程的转录因子。贝叶斯模型将用于识别模式和时间关系，以预测转录网络，这将使用遗传方法进行验证，以迭代的方式。乙烯调节转录因子的结合位点将通过计算和实验方法确定。更广泛的影响包括学生研究训练和服务学习项目，其目标是通过教高中生参与非专业本科生的科学。该项目将支持协调和组织学校访问，评估本科生的学习成果，并将该项目推广到其他学术机构。

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.