Loss of CsCLV2 function causes dwarfism and determinates growth in cucumber

Cucumber (Cucumis sativus L.) is a globally important vegetable crop. Ideal plant architecture optimizes spatial utilization, enhances economic coefficient, and facilitates mechanized cultivation. In this study, we identified a dwarf mutant, csdw3, exhibiting reduced plant height, shortened internodes, and fewer internodes. Genetic analysis showed that this dwarf phenotype is controlled by a single recessive gene. Fine-mapping localized the causal locus to an 80 kb region on chromosome 1, where we discovered a 102 bp deletion in CsCLV2, a gene encoding a leucine-rich repeat receptor-like protein homologous to Arabidopsis CLAVATA2. CRISPR-Cas9-generated loss-of-function mutants recapitulated the dwarf phenotype, confirming the role of CsCLV2 in plant height regulation. Histological examination revealed that CsCLV2 disruption causes premature termination of shoot apical meristem (SAM) development, reducing both internode number and length. Protein interaction assays further demonstrated that CsCLV2 associates with receptor-like kinase CsCIK1 (CLAVATA3 INSENSITIVE RECEPTOR KINASES 1), indicating their cooperative function in the CLV-WUS signaling pathway to maintain meristem activity. Our findings uncover a regulator of plant height in cucumber and provide valuable genetic resources for breeding ideotypes optimized for yield and cultivation efficiency.