Long-Term In Vivo Imaging of Luciferase-Based Reporter Gene Expression in Arabidopsis Roots

Plants have an amazing capacity to adjust their growth to environmental limitations. This is particularly relevant for the root system that tunes its developmental pattern to mine the soil for water and nutrients while avoiding patches of soil that contain biotic and abiotic stress agents. Because most developmental processes are taking place gradually while roots are growing, it is often difficult to correlate gene expression events with specific developmental processes that are not necessarily coinciding in time and space. Therefore, in vivo detection and quantification of gene expression over a long period under gravitational conditions can be instrumental in dissecting complex processes in the root. Here, we describe a method for long-term imaging of luciferase dynamics in growing Arabidopsis roots that express a luciferase gene driven by the auxin-output reporter DR5, in the context of lateral root development.