In vivo imaging of cGMP in plants.

The cyclic nucleotide 3',5'-cyclic guanyl monophosphate (cGMP) has been implicated in the regulation of important plant processes. To unravel its physiological role further, accurate recording of dynamic changes in cGMP concentration is necessary. Fluorescent sensors based on biological molecules for "live imaging" are ideal for this since they have high specificity, a sensitivity that is in the range of biologically relevant concentrations, high spatial and dynamic resolution, and measurements with such sensors are nondestructive. In this chapter we describe the use of the cGMP FlincG sensor in plant materials that either transiently or stably express this sensor.