A type 2C protein phosphatase activates high-affinity nitrate uptake by directly dephosphorylating NRT2.1 in Arabidopsis
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ABSTRACT: 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 nitrogen (N) starvation. However, critical enzymes required for post-translational activation of NRT2.1 remain to be identified. Here, we show that a type 2C protein phosphatase, designated CEPD-induced phosphatase (CEPH), activates high-affinity nitrate uptake by directly dephosphorylating S501 of NRT2.1, a residue that functions as a negative phospho-switch. CEPH is predominantly expressed in epidermal and cortex cells in roots and up-regulated by N starvation via a CEPDL2/CEPD1/2-mediated long-distance signaling from shoots. Loss of CEPH leads to a marked decrease in high-affinity nitrate uptake, tissue nitrate content, and plant biomass. Collectively, our results identify CEPH as a crucial enzyme in N starvation-dependent activation of NRT2.1, providing molecular and mechanistic insights into how plants regulate high-affinity nitrate uptake at the post-translational level in response to the N environment. We prepared total RNA from roots of wild type, CEPD1ox, CEPD2ox and CEPDL2ox plants grown on N-replete vertical plates for 14 d, and used a microarray analysis to identify genes specifically induced by CEPD family peptides.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE160649 | GEO | 2020/11/06
REPOSITORIES: GEO
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