Peptide hormones are important growth regulators that play various roles in many organisms. Although the importance of genes that encode peptide hormones is broadly recognized, most peptides have yet to be functionally characterized. Using genome editing technology, researchers from Kumamoto University, Japan generated a new, comprehensive genetic resource collection of plants with knocked out CLE peptides-encoding genes. CLE peptides are a group of plant-specific peptide hormones that play a role in cell signaling and are regulated by CLE genes. This open collection is expected to contribute to future studies on how peptide hormones work in plants.