Tetratricopeptide repeat (TPR) proteins play numerous roles in plant growth and development by mediating protein–protein interactions in biological systems by binding to peptide ligands. Although genome-wide analyses of the TPR gene family in other species have been performed, its evolution and function in Cucurbitaceae remain unclear. In this study, 144 TPR genes from 11 genomes of eight Cucurbitaceae species with a heterogeneous distribution on the chromosomes were characterized. Based on the homology between Cucurbitaceae and Arabidopsis, the TPR genes were divided into four groups, and the evolutionary relationships of the Benincaceae and Cucurbitaceae tribes were also represented in a phylogenetic tree. Using the ‘DHL92′ genome as a reference, an integrated chromosome map was obtained containing 34 loci, 4 of which were common to the Cucurbitaceae. Cis-regulatory element analysis showed that these elements are essential for melon development and responses to light, phytohormones, and various stresses. CmTPR tissue- and development-specific expression analysis revealed differential expression patterns under normal growth conditions. Furthermore, the CmTPR genes responded to various abiotic stressors. Overall, this study offers insights into the evolutionary history of the TPR gene family in Cucurbitaceae and provides valuable information for elucidating the potential role of CmTPR genes during development and under different stresses in melon.

Combining antibiotics with propolis is an effective method to combat bacterial drug resistance. Nanoparticles are of interest in the antimicrobial field because of their higher drug stability, solubility, penetration power, and treatment efficacy. In this study, propolis nanoparticles (PNPs) were synthesized, and their antibacterial and anti-biofilm activities against methicillin-resistant Staphylococcus aureus (MRSA) in combination with ampicillin sodium (AS) were analyzed. The PNPs had an average particle diameter of 118.0 nm, a polydispersity index of 0.129, and a zeta potential of −28.2 mV. The fractional inhibitory concentration indices of PNPs and AS against tested MRSA strains highlighted this synergy, ranging between 0.375 and 0.5. Crystal violet staining showed that combined PNPs and AS significantly inhibited biofilm formation and reduced existing biofilm biomass. We then discovered that PNPs inhibited bacterial adhesion, extracellular polysaccharide synthesis, and mecR1, mecA, blaZ, and icaADBC gene expression. These results indicated that PNPs exerted a synergistic antibacterial effect with AS by inhibiting mecR1, mecA, and blaZ gene expressions to reduce the drug resistance of MRSA. Meanwhile, PNPs weakened bacterial adhesion and aggregation by suppressing icaADBC gene expression, allowing antibiotics to penetrate the biofilm, and exhibiting significant synergistic anti-biofilm activity. In summary, PNPs are promising candidates for combating MRSA-related diseases.

Background: O-methyltransferase (OMT)-mediated O-methylation is a frequent modification that occurs during natural product biosynthesis, and it increases the diversity and stability of secondary metabolites. However, detailed genome-wide identification and expression analyses of OMT gene family members have not been performed in melons. In this study, we aimed to perform the genome-wide identification of OMT gene family members in melon to identify and clarify their actions during stress. Methods: Genome-wide identification of OMT gene family members was performed using data from the melon genome database. The Cucumis melo OMT genes (CmOMTs) were then compared with the genes from two representative monocotyledons and three representative dicotyledons. The basic information, cis-regulatory elements in the promoter, predicted 3-D-structures, and GO enrichment results of the 21 CmOMTs were analyzed. Results: In our study, 21 CmOMTs (named CmOMT1-21) were obtained by analyzing the melon genome. These genes were located on six chromosomes and divided into three groups composed of nine, six, and six CmOMTs based on phylogenetic analysis. Gene structure and motif descriptions were similar within the same classes. Each CmOMT gene contains at least one cis-acting element associated with hormone transport regulation. Analysis of cis-acting elements illustrated the potential role of CmOMTs in developmental regulation and adaptations to various abiotic and biotic stresses. The RNA-seq and quantitative real-time PCR (qRT-PCR) results indicated that NaCl stress significantly induced CmOMT6/9/14/18 and chilling and high temperature and humidity (HTH) stresses significantly upregulated CmOMT14/18. Furthermore, the expression pattern of CmOMT18 may be associated with Fusarium oxysporum f. sp. melonis race 1.2 (FOM1.2) and powdery mildew resistance. Our study tentatively explored the biological functions of CmOMT genes in various stress regulation pathways and provided a conceptual basis for further detailed studies of the molecular mechanisms.

Trehalose (Tre) is a non-disaccharide that regulates environmental stress tolerance in animals and plants, and is synthesized by Trehalose-6-phosphate synthase (TPS). This study aimed to analyze TPS genes in bottle gourd as this species has not been investigated before despite its economic importance and health benefits. Six TPS genes in Lagenaria siceraria (LsTPS) were identified and found to be distributed across six chromosomes. The LsTPS genes were categorized into Classes I and II based on their homology with Arabidopsis, rice, cucumber, watermelon, and tomato. Variable exon numbers were found in the LsTPS genes, with more exons in Class II than in Class I genes. GO term enrichment and cis-regulatory element analyses indicated that LsTPS genes participate in Tre synthesis and environmental stress responses. Structural analysis of TPS proteins revealed that LsTPS5 has a transmembrane helix, an α-helix and β-sheet. Gene duplication analysis indicated that purifying selection drove the evolution of the LsTPS family. We found that LsTPS genes are widely expressed in all plant tissues, and LsTPS1/5 are constitutively expressed in all tissues. RNA-sequencing and quantitative real-time PCR data showed that LsTPS expression changed significantly in response to environmental stressors. This study provides to foundation for further research on the roles of the LsTPS gene and Tre in abiotic and biotic stress response and provides important insights for the development of genetic engineering methods to alter Tre metabolism and interactions with other molecules.

TCP genes are plant-specific transcription factors that play essential roles in plant growth, development, metabolism, and responses to biotic and abiotic stresses. However, the roles of TCP genes in Cucurbitaceae species remain unknown. In this study, 111 and 119 TCP genes were identified in the Benincaseae (C. melo, C. sativus, C. lanatus and L. siceraria) and Cucurbiteae (C. maxima, C. moschata and C. pepo) tribes, respectively, and were analyzed. Segmental duplication, tandem duplication, and whole-genome duplication (WGD) were identified as the major driving factors in the expansion of TCP genes in Cucurbitaceae species, with the majority of TCP genes undergoing purifying selection. Using the melon genome as a reference, an integrated map containing 29 loci across nine chromosomes was constructed, 28 of which were shared by seven Cucurbitaceae species. Gene structure analysis revealed that their function was conserved. The result of promoter sequence analysis indicated that TCP genes have many phytohormone-related cis-regulatory elements. GO term enrichment analysis showed that TCP genes were the major regulators of many downstream transcriptional networks and primarily functioned in the nucleus. Transcriptome analysis of different tissues and developmental stages of the Cucurbiteae tribe revealed tissue-specific spatial and temporal expression patterns of TCP genes, suggesting that TCP genes play an important role in the growth and development of Cucurbitaceae. Gene expression profiling demonstrated that TCP genes are involved in the responses of plants to abiotic and biotic stresses. In conclusion, this is the first systematic analysis of TCP genes in Cucurbitaceae, which provides deeper insights into their evolutionary dynamics and functional properties, which may be crucial for the genetic improvement of Cucurbitaceae.

Lagenaria siceraria is an essential horticultural and medicinal crop that is used for its edible fruits and ornamental purposes. WRKY transcription factors have been extensively studied in plant responses to environmental stress; however, there is limited information on their specific functions in L. siceraria. In this study, 51 LsWRKY genes were identified in the L. siceraria genome. The 51 LsWRKYs were divided into classes I, II, and III based on evolutionary analysis. Members of each class have similar conserved motifs and exon-intron structures, and promoter analysis helped identify many cis-regulatory elements associated with growth, hormones, and stress responses. GO terms and KEGG analyses indicated the potential roles of LsWRKY in the regulation of bottle gourd development and acclimation to various environmental stressors. Significant differences in LsWRKY expression were observed between different tissues. The results of RNA-seq and qRT-PCR showed that LsWRKYs were expressed in a tissue- and development-specific manner under normal growth conditions. LsWRKY abundance showed a clear pattern of change related to stress when L. siceraria was exposed to unfavorable environmental conditions. This study provides new insights into the role of LsWRKYs in the growth and stress responses of cucurbits.