PSY-PSYR peptide-receptor pairs control the trade-off between plant growth and stress response.

Leucine-rich repeat-receptor kinases (LRR-RKs) perceive various endogenous peptide hormones that control plant growth and development. However, the majority of corresponding ligands and their direct ligand-binding receptors have not been identified yet. A recent study demonstrated that three LRR-RK PLANT PEPTIDE CONTAINING SULFATED TYROSINE RECEPTORS (PSYRs) act as ligand-receptors of the PSY family peptides that mediate the trade-off between the optimal plant growth and stress tolerance responses. The genetic, biochemical, and transcriptome analyses suggested that PSYR1, PSYR2, and PSYR3 function as negative regulators of plant growth in the absence of PSY peptides and induce stress tolerance responses, whereas the PSY family peptides repress PSYR signaling, allowing plant growth. This trade-off mechanism between plant growth and stress responses mediated by the PSY-PSYR signaling module allows plants to survive under ever changing environmental stresses.