MPI-MP SUMMER SERIES: Regulation of plant nitrogen acquisition by long-distance mobile peptides and a novel phosphatase in plant - Yuri Ohkubo

Nitrogen is an essential macronutrient in plants. Plants take up inorganic N directly from the soil, mainly in the form of nitrate. However, nitrate is often distributed heterogeneously in natural soil. Plants employ long-distance peptide signaling to maintain N homeostasis. When roots are subjected to nitrate-limited conditions, the starvation-induced peptide CEP acts as a root-derived ascending N-starvation signal to the shoots, where its perception by receptors leads to the production of shoot-derived descending CEPD1 (CEP downstream 1) and CEPD2, which elevate high-affinity nitrate uptake in the roots. The nitrate transporter NRT2.1, which plays a central role in high-affinity nitrate uptake in roots, is activated at the post-translational level in response to N-starvation. However, the critical enzymes required for the post-translational activation of NRT2.1 remain to be identified. Recently, we reported that a type 2C protein phosphatase, designated CEPD-induced phosphatase (CEPH), activates high-affinity nitrate uptake by directly dephosphorylating Ser501 of NRT2.1, a residue that functions as a negative phospho-switch in Arabidopsis. Our results identify CEPH as a crucial enzyme in the N-starvation-dependent activation of NRT2.1. In this seminar, I will talk about how plants regulate high-affinity nitrate uptake at the post-translational level in response to the N environment.

Zoom invitation: Please contact castellanos@mpimp-golm.mpg.de