Characterization of Fluorescence-Based Bacterial Biosensors that are Responsive to Water Stress

点击翻译按钮获取中文摘要

Microbial growth, survival and activity are strongly influenced by environmental conditions. Although the average environmental conditions across a given habitat can be easily measured, the conditions that are actually sensed by bacteria in individual microhabitats are more important to the ecology of the bacteria than the average conditions. Currently, there are few environmental monitoring tools that function on the scale of a microorganism. The goal of this study is to develop a new tool that will allow us to "see a microhabitat from a bacterium's perspective." This tool, called a bacteria] biosensor, is a bacterium that visibly changes when it senses a particular environmental condition. The biosensors that are the focus of this study are bacteria that "glow" or fluoresce when they sense limited water availability. This study will characterize the range of detection and specificity of several water stress-responsive bacterial biosensors that are designed for use on plant leaves. This study will also test whether the operating range of these biosensors is appropriate for evaluating bacterial exposure to limited water availability on plant leaves.Bacteria on plant leaves are exposed to large and frequent changes in environmental conditions, particularly in water availability. Understanding the extent to which these bacteria are limited for water is crucial to identifying the survival strategies bacteria employ on leaves, to identifying the process by which bacteria colonize leaves, and to our general understanding of the ecology of these organisms. This information will contribute to strategies for maximizing the survival of bacteria introduced onto leaves, such as for controlling plant diseases or promoting plant growth. Furthermore, demonstrating the effectiveness of these water-stress responsive bacterial biosensors will lay the foundation for building similar tools to evaluate other microbial habitats, as well as other environmental conditions in the leaf surface habitat.