A novel nitrate transport activity sensor- NiTra-NPF1.3
The NRT1/PTR FAMILY (NPF) in Arabidopsis (Arabidopsis thaliana) plays a major role as a ni-trate transporter. The first nitrate transporter activity biosensor NiTrac1 converted the du-al-affinity nitrate transceptor NPF6.3 into fluorescence activity sensors. To test whether this ap-proach is transferable to other members of this family, screening for genetically encoded fluores-cence transport activity sensor was performed with the member of the NPF family in Arabidopsis. In this study, NPF1.3, an uncharacterized member of NPF in Arabidopsis, was converted into a transporter activity biosensor NiTrac-NPF1.3 that responds specifically to nitrate. The emission ratio change of NiTrac-NPF1.3 triggered by the addition of nitrate reveals the important function of NPF1.3 in nitrate transport in Arabidopsis. A functional analysis of Xenopus laevis oocytes confirmed that NPF1.3 plays a role as a nitrate transporter. This new technology is applicable in plant and medical research.