Cucumber (Cucumis sativus, Cs) tendrils are slender vegetative organs that typically require manual removal to ensure orderly growth during greenhouse cultivation. Here, we identified cucumber tendril-less (tl), a Tnt1 retrotransposon-induced insertion mutant lacking tendrils. Map-based cloning identified the mutated gene, CsaV3_3G003590, which we designated as CsTL, which is homologous to Arabidopsis thaliana LATERAL SUPPRESSOR (AtLAS). Knocking out CsTL repressed tendril formation but did not affect branch initiation, whereas overexpression of CsTL resulted in the formation of two or more tendrils in one leaf axil. Although expression of two cucumber genes regulating tendril formation, Tendril (CsTEN) and Unusual Floral Organs (CsUFO), was significantly decreased in CsTL knockout lines, these two genes were not direct downstream targets of CsTL. Instead, CsTL physically interacted with CsTEN, an interaction that further enhanced CsTEN-mediated expression of CsUFO. In Arabidopsis, the CsTL homolog AtLAS acts upstream of REVOLUTA (REV) to regulate branch initiation. Knocking out cucumber CsREV inhibited branch formation without affecting tendril initiation. Furthermore, genomic regions containing CsTL and AtLAS were not syntenic between the cucumber and Arabidopsis genomes, whereas REV orthologs were found on a shared syntenic block. Our results revealed not only that cucumber CsTL possesses a divergent function in promoting tendril formation but also that CsREV retains its conserved function in shoot branching.

Photosynthesis, a critical process occurring the chloroplast, supports essential metabolic pathways crucial for plant survival and adaptive responses. This study explores the cucumber tnyl2 mutant's impact on photosynthesis and chloroplast development, highlighting critical metabolic pathways essential for plant adaptability. The tnyl2 mutant, characterized by stunted growth and a photo-bleached phenotype, reveals a compromised chloroplast structure and function. Through genetic analysis, CsUMPK (Csa6G483490) emerged as the pivotal gene associated with these abnormalities, playing a vital role in chlorophyll synthesis and chloroplast integrity. Reduced chlorophyll levels and altered chloroplast architecture in the mutant underscore CsUMPK's significance. Moreover, the decline in CAB genes expression and potential intron splicing abnormalities due to CsUMPK dysfunction emphasize its essentiality in the photosynthetic apparatus. The present findings highlight the crucial contribution of CsUMPK to photosynthetic efficiency and chloroplast formation, offering insights into the molecular basis of photosynthesis across plant species.

Light quality influences the flavor of oriental melon (Cucumis melo var. makuwa Makino) fruit, and aroma volatiles are important determinants of flavor quality. Here, we found red light (RL) enhances the total volatile compounds in melon fruit, especially acetate esters, by activating the expression of the key lipoxygenase (LOX) pathway genes CmLOX18 and CmAAT1. The RL-inducible transcription factor CmDof13 was identified as a positive regulator of CmLOX18 and CmAAT1 in melon fruit. We also showed that total volatile compounds, esters, and ethyl acetate significantly decreased in the Cmdof13 knockout mutant relative to wild-type melon fruit. Moreover, PHYTOCHROME-INTERACTING FACTOR 8 (PIF8), which is transcriptionally downregulated by RL, inhibited CmDof13 transcription. After transient CmPIF8 overexpression in melon fruit, several ester compounds decreased. Moreover, CmPIF8 interacted with CmDof13 to regulate RL-induced ester biosynthesis. Overall, this study reveals that the CmPIF8–CmDof13–LOX pathway modulates RL-induced ester biosynthesis in oriental melon, illustrates the regulatory pathways underlying the impact of light quality on flavor quality, and provides a basis for the high-quality cultivation of oriental melon fruit under low light in greenhouse cultivation.

Trichomes, the hair‐like outgrowths of the plant epidermis, are critical for defence, reproduction and development. However, the underlying molecular mechanisms governing their initiation remain elusive. Here, we identified CsGL2, an AP2/ERF transcription factor, as a key integrator controlling trichome initiation and fruit development in cucumber. Genetic and molecular studies indicate that CsGL2 activates CsGL1 / Mict , subsequently triggering the morphogenesis of multicellular trichomes. Beyond epidermal fate, CsGL2 upregulates the tubercle regulator Tu together with the cytokinin rate‐limiting enzyme gene IPT1 , thereby initiating fruit tubercles through cytokinin‐linked pathways. Notably, we found that ovule‐specific CsGL2 activates the parthenocarpy gene CsNPF1 , and CsGL2 overexpression markedly increases the frequency of seedless fruit set. Thus, our findings establish a switch‐based mechanism for progressive cell‐fate specification in multicellular epidermal organs. This reveals how a single transcription factor integrates transcriptional and hormonal pathways to coordinate distinct developmental programmes.