Transcriptome Analysis of CsWOX1 Mutant and Overexpressing Lines Reveals Downstream Genes Regulating Cucumber Leaf Morphogenesis

WUSCHEL-related homeobox 1 (WOX1), categorized into the WUS clade, has been determined as the essential gene for leaf expansion as well as promoting leaf outgrowth along the medio-lateral axis. In cucumbers, the phenotypic characteristics of transgenic materials with CsWOX1 overexpression (CsWOX1-OE) and mutants (mango fruit, mf) have been reported. presenting as leaves with a "butterfly-shaped" appearance and a rapid reduction in the area of leaf tips, respectively.In this study, RNA-Seq was employed to sequence the transcriptome of CsWOX1-OE to reveal its differentially expressed genes (DEGs). GO classification and KEGG pathway enrichment analyses were performed, revealing new links between the WOX1 protein and many core plant regulatory pathways. Further joint analysis identified eighty common DEGs between CsWOX1-OE and mf, with a significant proportion of these common DEGs being annotated to the circadian pathway and the auxin polarity transport pathway. Six genes were selected for Y1H and Dual-LUC interaction validation experiments. These experiments demonstrated that CsWOX1 directly targets the promoters of CsRVE6, which regulates leaf expansion, and CsPin1At, which is involved in auxin polarity transport, thereby promoting their transcription.In conclusion, these findings provide a foundation for exploring the potential regulatory mechanisms associated with CsWOX1, expecting to contribute to the construction of a more comprehensive gene network for leaf morphogenesis.Key words: cucumber, CsWOX1, RNA-Seq, leaf morphogenesis.