CsNWD Encoding VPS62 Emerges as a Candidate Gene Conferring the Glabrous Phenotype in Cucumber

The commercial value of cucumbers is influenced by the presence of spines or trichomes on their fruit, while the trichomes found on other parts of the plant are essential for protecting the cucumber against a range of biotic and abiotic stresses. In our research, we identified a glabrous nwd mutant from EMS-induced cucumber (Cucumis sativus L.) mutant lines. This mutant displays a consistent glabrous phenotype across all plant organs. Upon analysis, it was revealed that the nwd mutation is governed by a lone recessive nuclear gene. The nwd plants show a significant reduction in both their photosynthetic capacity and chlorophyll a content when compared to the wild-type. Furthermore, there are notable changes in the antioxidant enzyme activities, soluble protein levels, and malondialdehyde content of the nwd mutant. Genotyping and MutMap approaches identified the CsNWD gene, encoding a VPS protein, as a candidate responsible for the glabrous trait. Transcriptome analysis indicated that 15 trichome-related genes exhibit significant expression changes in the nwd mutant, implying that CsNWD may regulate trichome development through interactions with these genes. This study contributes to the understanding of VPS proteins in trichome initiation and the underlying mechanisms of trichome development.