cucumber 649 Raw sequence reads. Cucumis sativus

Lateral organ development is important for cucumber yield, while the molecular mechanism controlling leaf and floral organ development in cucumber remain elusive. In this report, a novel EMS-mutaginized mutant, round leaf (rl) was distinguished with remarkable round leaf shape, abnormal floral organ and inhibited tendril outgrowth in early development phase. Moreover, the ovule organogenesis disrupted completely in parthenocarpy fruit of rl. MutMap+ analysis revealed that RL encodes a protein kinase PINOID (CsPID, Csa1G537400). A non-synoymous SNP in the second exon of CsPID resulted in an amino-acid substitution from Arg in the wild type to Lys in the rl mutant. CsPID was down-regulated in rl mutant and preferentially expressed in young leaf, and flower buds. IAA quantification showed that rl plants exhibited a lower IAA content than wild type in ovary and blade edge. IAA immunolocalization results confirmed the IAA content alteration in rl plants. Transcriptome profile analysis further suggested IAA biosynthesis, polar transport and signal transduction genes participated in the leaf and floral development process by CsPID. Biochemical analyses showed that CsPID may regulate leaf shape by interacting with CsREV. In conclusion, this study revealed that the extensive genetic architecture of lateral organ organogenesis and development via CsPID regulating auxin polar transport action in cucumber.