In vivo visualization of nitrate dynamics using a genetically encoded fluorescent biosensor
Yen-Ning Chen, Heather Cartwright, Cheng-Hsun Ho
Abstract
Nitrate (NO 3 − ) uptake and distribution are critical to plant life. Although the upstream regulation of NO 3 − uptake and downstream responses to NO 3 − in a variety of cells have been well studied, it is still not possible to directly visualize the spatial and temporal distribution of NO 3 − 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 NO 3 − distribution in Arabidopsis thaliana . This biosensor tracked the spatiotemporal distribution of NO 3 − along the primary root axis and disruptions by genetic mutation of transport (low NO 3 − uptake) and assimilation (high NO 3 − accumulation). The developed biosensor effectively monitors NO 3 − concentrations at the cellular level in real time and spatiotemporal changes during the plant life cycle.