Extracellular signaling peptide that represses primary root growth rate and significantly inhibits lateral root formation. Modulates leaf morphology (PubMed:24179096). Regulates systemic nitrogen (N)-demand signaling. Mediates up-regulation of genes involved in N uptake and assimilation pathways (PubMed:25324386). Interacts with CEP receptors (e.g. CEPR1 and CEPR2). Accumulates in xylem sap under nitrogen (N)-starved conditions. Accumulates in xylem sap under nitrogen (N)-starved conditions. Accumulates in xylem sap under nitrogen (N)-starved conditions. Accumulates in xylem sap under nitrogen (N)-starved conditions. Accumulates in xylem sap. Expressed in lateral root primordia and in lateral roots excluding the meristem region. Also present in the aerial tissues, such as leaf petioles and the shoot apex region. Induced by nitrogen (N) and potassium (K), but repressed by auxin (PubMed:24179095). Repressed in shoots in response to ammonium chloride NH(4)Cl and osmotic stress (e.g. mannitol) (PubMed:24179096). Triggered by nitrogen depletion (PubMed:25324386). Hydroxylated peptide is more active than non-hydroxylated peptide. The mature small signaling peptide is generated by proteolytic processing of the longer precursor. Belongs to the C-terminally encoded plant signaling peptide (CEP) family. Extended C-terminus. Truncated N-terminus. Truncated N-terminus.