Intellectual Merit: The ability of plants to perceive and acclimate to changes in the environment is paramount for their survival. Not only is this true for plants growing in nature, but also for plants growing in the field. The root system represents the primary site of perception and response for many stressful environmental conditions such as high salinity, the most widespread soil contaminant negatively affecting agriculture. Absorption of sodium ions by the root system causes nutrient deficiencies and inhibits the growth of the shoot. Arabidopsis thaliana has evolved several stress-resistance mechanisms and serves as a model system for understanding how the regulation of genes enables acclimation to salinity. The goal of this research program is to determine the regulatory mechanisms that control spatial and temporal aspects of the stress response. Gene activity is regulated through short DNA-sequences in the promoter region, known as cis-regulatory elements. These elements act like a code that determines how a particular gene is expressed by recruiting transcription factor proteins, which ultimately determine gene activity. This project aims to crack the cis-element code for salt stress response through the use of novel cell-type specific gene expression data sets and synthetic biology approaches. A network of cis-elements and transcription factors will be generated to elucidate the complex molecular interactions controlling spatiotemporal aspects of the response. This work will contribute to an understanding of gene regulatory networks in plants and provide tools for engineering salt-tolerant plants.
Broader Impact: Understanding how plants regulate gene activity under stressful conditions is necessary for the development of crops better able to grow on marginal agricultural land. In particular, an understanding of the regulatory code used to turn genes on and off in specific tissues and at specific times during the stress response is critical to generate plants that perform well under both ideal and suboptimal conditions. This research program will also provide a platform for training students and scientists on the use of genomic and synthetic biology approaches to address important questions in plant biology. A mentoring program will be established to provide enrichment activities for underprivileged youth at the Boys and Girls Club of the Peninsula. The planned program will involve hands on activities aimed at introducing students to basic concepts in plant biology and biotechnology. The goals will be to instill an appreciation for the role plants play in their lives, how different cultures have contributed to the history of plant breeding and finally how biotechnology is changing the pace of future agricultural development.
