記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Plants  

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 nitrogen (N) starvation1,2. However, the critical enzymes required for the 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 Ser501 of NRT2.1, a residue that functions as a negative phospho-switch in Arabidopsis2. CEPH is predominantly expressed in epidermal and cortex cells in roots and is upregulated by N starvation via a CEPDL2/CEPD1/2-mediated long-distance signalling from shoots3,4. The loss of CEPH leads to marked decreases in high-affinity nitrate uptake, tissue nitrate content and plant biomass. Collectively, our results identify CEPH as a crucial enzyme in the N-starvation-dependent activation of NRT2.1 and provide molecular and mechanistic insights into how plants regulate high-affinity nitrate uptake at the post-translational level in response to the N environment.

DOI： 10.1038/s41477-021-00870-9

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PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Plants  

Plants uptake nitrogen (N) from the soil mainly in the form of nitrate. However, nitrate is often distributed heterogeneously in natural soil. Plants, therefore, have a systemic long-distance signalling mechanism by which N starvation on one side of the root leads to a compensatory N uptake on the other N-rich side 1,2. This systemic N acquisition response is triggered by a root-to-shoot mobile peptide hormone, C-TERMINALLY ENCODED PEPTIDE (CEP), originating from the N-starved roots 3,4, but the molecular nature of the descending shoot-to-root signal remains elusive. Here, we show that phloem-specific polypeptides that are induced in leaves upon perception of root-derived CEP act as descending long-distance mobile signals translocated to each root. These shoot-derived polypeptides, which we named CEP DOWNSTREAM 1 (CEPD1) and CEPD2, upregulate the expression of the nitrate transporter gene NRT2.1 in roots specifically when nitrate is present in the rhizosphere. Arabidopsis plants deficient in this pathway show impaired systemic N acquisition response accompanied with N-deficiency symptoms. These fundamental mechanistic insights should provide a conceptual framework for understanding systemic nutrient acquisition responses in plants.

DOI： 10.1038/nplants.2017.29

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その他リンク： https://www.nature.com/articles/nplants201729

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Science  

Deciding whether to grow or to divert energy to stress responses is a major physiological trade-off for plants surviving in fluctuating environments. We show that three leucine-rich repeat receptor kinases (LRR-RKs) act as direct ligand-perceiving receptors for PLANT PEPTIDE CONTAINING SULFATED TYROSINE (PSY)-family peptides and mediate switching between two opposing pathways. By contrast to known LRR-RKs, which activate signaling upon ligand binding, PSY receptors (PSYRs) activate the expression of various genes encoding stress response transcription factors upon depletion of the ligands. Loss of PSYRs results in defects in plant tolerance to both biotic and abiotic stresses. This ligand-deprivation–dependent activation system potentially enables plants to exert tuned regulation of stress responses in the tissues proximal to metabolically dysfunctional damaged sites where ligand production is impaired.

DOI： 10.1126/science.abq5735

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PubMed

記述言語：日本語   出版者・発行元：公益社団法人 日本農芸化学会  

DOI： 10.1271/kagakutoseibutsu.60.352

CiNii Research

CiNii Research