The nuclear factor Y (NF-Y) transcription factor contains three subfamilies: NF-YA, NF-YB, and NF-YC. The NF-Y family have been reported to be key regulators in plant growth and stress responses. However, little attention has been given to these genes in melon (Cucumis melo L.). In this study, twenty-five NF-Ys were identified in the melon genome, including six CmNF-YAs, eleven CmNF-YBs, and eight CmNF-YCs. Their basic information (gene location, protein characteristics, and subcellular localization), conserved domains and motifs, and phylogeny and gene structure were subsequently analyzed. Results showed highly conserved motifs exist in each subfamily, which are distinct between subfamilies. Most CmNF-Ys were expressed in five tissues and exhibited distinct expression patterns. However, CmNF-YA6, CmNF-YB1/B2/B3/B8, and CmNF-YC6 were not expressed and might be pseudogenes. Twelve CmNF-Ys were induced by cold stress, indicating the NF-Y family plays a key role in melon cold tolerance. Taken together, our findings provide a comprehensive understanding of CmNF-Y genes in the development and stress response of melon and provide genetic resources for solving the practical problems of melon production.

Copper (Cu) pollution resulting from human activities has emerged as a prominent issue stemming from industrial development. The entry of copper into the soil, either directly or through industrial wastewater, exerts adverse effects on plant growth, leading to its accumulation in significant quantities within the plant and subsequent endangerment of human health through the food chain. DCPTA [2-(3, 4-dichlorophenoxy) triethylamine] mitigates certain abiotic stresses, yet the precise mechanism by which it alleviates Cu-induced phytotoxicity remains unknown. This study has demonstrated that DCPTA reduces the impact of copper stress on plants by enhancing leaf pigment and photosynthesis, regulating root growth, and balancing the antioxidant system. Furthermore, the accumulation of Cu in leaves and roots of cucumber treated with DCPTA was significantly lower than that in seedlings treated with Cu alone. Transcriptome analysis showed that copper absorption, transport, detoxification genes, cell wall component related genes and nitrogen metabolism related genes played a crucial role. In conclusion, exogenous application of DCPTA can partially alleviate copper stress in cucumber.

Nodule inception-like Protein (NLP) family genes, as transcription factors, play an important role in regulating physiological responses of plants to adapt to external nitrogen environment changes. However, there are few reports on NLP genes in cucumber. In this study, we identified members of the cucumber family, conducted a comprehensive bioinformatics analysis of them, analyzed their evolutionary relationships, and predicted their potential functions. The results showed that there were 3 homologous genes in cucumber. The evolutionary analysis of NLPs in different species showed that the NLP family proteins mostly contained three conserved domains: RWP-RK, PB-1 and GAF-like domains. All of them contained four introns and five exons, and the motif composition and protein structure were similar. By analyzing the promoter region, it was found that the cucumber NLP gene family contains cis-acting elements related to plant growth, environmental stress and hormone signaling, suggesting that this gene family may be involved in the growth and development of cucumber under stress and stress response. The cucumber NLP family genes were expressed in root, stem, leaf, flower, NLP and fruit tissues, and the CsNLP2 gene showed the highest expression in leaves. Interestingly, family genes respond to both nitrogen environment changesand abiotic stresses, especially CsNLP2. Further subcellular localization analysis showed that CsNLP2 was mainly located in the nucleus. The CsNLP2 transcription factor positively regulates the expression of CsNRT2.3 gene, which encodes the nitrate transporter. Overall, CsNLP2 was a strong candidate gene for improving nitrogen use efficiency in cucumber.

Substrate cultivation is a widely used method in greenhouses to address the deterioration of the soil environment caused by excessive fertilization. However, the effects and relationships of fertilization treatments on stoichiometric characteristics, rhizosphere soil microorganisms, and metabolites are still unclear. To determine the optimal amount and frequency, two fertilization intervals (every 5 days and every 10 days) and four total fertilization levels (378.5, 529.9, 605.6, and 757.0 kg·ha⁻¹) were considered, along with a control (CK). Among the treatments, T6 (every 10 days with a total fertilization amount of 605.6 kg·ha⁻¹) resulted in the best pepper plant growth, highest photosynthetic capacity, and maximum yield. Fertilization significantly changed the species composition and community structure of rhizosphere microorganisms. It also affected the composition of rhizosphere metabolites, with differential metabolites significantly enriched in alanine, aspartate, and glutamate metabolism, as well as butanoate metabolism. This study provides insights into high-quality and high-yield cultivation of peppers, as well as the rhizosphere microorganisms and metabolites that play an important role in production.