Live Imaging of Grass Roots Growth Dynamics Using Microfluidics.

Microfluidic tools enable manipulation of microliter-scale volumes within a stable microenvironment. Microfluidics has been widely adopted in various biological fields for, among other applications, controlled delivery of sensory, chemical, and mechanical stimuli to the observed organisms. In this chapter, we describe the design and usage of a custom-made double-layered PDMS microfluidic device, named BUGchip, developed for the purpose of studying plant root growth and metabolic responses in rapidly changing conditions with a high time-scale resolution. We demonstrate the utility of this device by a showcase experiment with a hyperosmotic treatment of Brachypodium distachyon roots, in which changes in growth rate and relative pH across the root surface in response to the treatment can be observed within minutes.