In vivo visualization of nitrate dynamics using a genetically encoded fluorescent biosensor

Nitrate (NO3-) uptake and distribution are critical to plant life. Although the upstream regulation of NO3- uptake and downstream responses to NO3- in a variety of cells have been well studied, it is still not possible to directly visualize the spatial and temporal distribution of NO3- with high resolution at the cellular level. Here, we report a nuclear-localized, genetically encoded fluorescent biosensor, which we named NitraMeter3.0, for the quantitative visualization of NO3- distribution in Arabidopsis thaliana. This biosensor tracked the spatiotemporal distribution of NO3- along the primary root axis and disruptions by genetic mutation of transport (low NO3- uptake) and assimilation (high NO3- accumulation). The developed biosensor effectively monitors NO3- concentrations at the cellular level in real time and spatiotemporal changes during the plant life cycle.

Automated summary

This study reports a nuclear-localized, genetically encoded fluorescent biosensor, NitraMeter3.0, for the quantitative visualization of nitrate distribution in Arabidopsis thaliana. The biosensor tracked the spatiotemporal distribution of nitrate along the primary root axis and monitored the disruptions by genetic mutation.