Search Results (344)

The Shymkent–Saryagash–Abay (A-15) international highway is a major Kazakhstan–Uzbekistan freight corridor that runs through the irrigated horticultural belt of the Turkestan Region in South Kazakhstan, where adjacent fields supply vegetables and cucurbits to the regional market. Composite soil samples (n = 18) were taken at six distances (2–300 m) from the road edge across three locations during 2022–2023, along with edible fruits of tomato, cucumber, watermelon, and melon (n = 12) from the adjoining fields. Pb, Zn, and Cd were measured via flame atomic absorption spectrometry after HNO₃/H₂O₂ digestion. Soil concentrations decreased sharply with distance (Pb: 26.3 → 5.98 mg kg⁻¹; Zn: 21.29 → 4.16; Cd: 0.47 → 0.01 mg kg⁻¹), exceeding the national soil MPCs by 1.5–3 times within 2–10 m. Pb and Zn exceeded the Kazakhstani food-safety MPCs in all four crops, and Cd in three of four (tomato, cucumber, and melon). Transfer factors followed the order of Cd (2.90–4.40) > Zn (1.99–3.00) > Pb (0.16–0.30), and the Cd geo-accumulation index ranged from 1.05 to 1.65 at 2–5 m. Adult dietary risk was acceptable (HI = 0.029–0.052; CR < 1.7 × 10⁻⁶), yet food-safety exceedances support a precautionary sanitary buffer and combined soil-and-crop monitoring along the corridor. Full article

The surface functionalization of mesoporous bioactive glasses (MBGs) is of critical importance for the development of advanced hybrid biomaterials with controlled interfacial and adsorption properties. Composite systems based on MBGs modified with cucurbit[n]urils (CB[6], CB[7], and CB[8]) were synthesized and systematically investigated to elucidate size-dependent interaction mechanisms and their influence on textural and physicochemical characteristics. Functionalization was achieved via aqueous deposition followed by controlled thermal treatment. Nitrogen sorption analysis revealed distinct pore modification behaviors: CB[6] reduced the specific surface area by 64% with partial pore occupation; CB[7] induced extensive mesopore occlusion (92.4% surface area reduction); whereas CB[8] produced a balanced decrease (71.2%) while largely preserving microporosity. Thermogravimetric analysis demonstrated comparable loading for CB[7] and CB[8], yet MBGs@CB[8] exhibited enhanced thermal stability, with the DTG maximum shifted to ~395 °C. Molecular modeling supported these findings, indicating the lowest adsorption energy for CB[8]. This combination of structural preservation and enhanced stability provides the most favorable balance between pore accessibility and structural modification, demonstrating strong potential as a versatile modifier for subsequent functionalization, including drug loading applications in bone-regenerative systems. Full article

Zeugodacus tau Walker (Diptera: Tephritidae) is a quarantine pest of cucurbit crops in China. In recent years, the damage it has caused to Trichosanthes kirilowii (Cucurbitales: Cucurbitaceae) has increased, but evidence for host adaptation and population growth on this plant remains limited. We investigated the suitability of T. kirilowii as a host plant for Z. tau, compared with the known suitable host Cucurbita moschata, by examining adult olfactory preference, oviposition choice, and demographic performance using an age–stage, two-sex life table. Females preferred T. kirilowii significantly more than C. moschata in cases of both peeled and unpeeled fruits, whereas males showed no significant difference. Oviposition was also higher on T. kirilowii and further increased on peeled fruit. Developmental duration, total longevity, ovipositing days, oviposition period, and hatching rate did not differ between the two host species. However, Z. tau reared on T. kirilowii exhibited significantly shorter APOP and TPOP, along with higher fecundity and increased pupal weight. Life table parameters indicated higher intrinsic (r = 0.1028 ± 0.0040 d⁻¹) and finite rates of increase (λ = 1.1083 ± 0.0044 d⁻¹) on T. kirilowii, whereas R₀ was similar and mean generation time was shortened by 11.61 d. A 100-day projection predicted 11,980 adults from T. kirilowii compared to 1231 from C. moschata. Overall, T. kirilowii is a highly suitable host that supports the rapid population growth of Z. tau. Full article

Cucurbit crops—including cucumber (Cucumis sativus), watermelon (Citrullus lanatus), and melon (Cucumis melo)—are of major economic and nutritional importance worldwide. Yet their productivity and quality are severely compromised by foliar fungal diseases, particularly powdery mildew (PM), downy mildew (DM), and target leaf spot (TLS). While PM and DM have been extensively studied, TLS has emerged as an increasingly prevalent and damaging disease in key production regions, yet it remains comparatively understudied—especially with respect to its molecular basis and comparative pathobiology relative to PM and DM. Current reliance on chemical fungicides is hampered by escalating pathogen resistance and concerns over residual toxicity, whereas conventional breeding approaches face inherent limitations in pyramiding durable, broad-spectrum resistance against multiple pathogens. In this context, cucumber has emerged as a pivotal model species for dissecting foliar disease resistance mechanisms in cucurbits, supported by a high-quality reference genome, extensive resequencing datasets, diverse germplasm collections, and an efficient Agrobacterium-mediated transformation system. Despite these advantages, existing reviews predominantly address PM or DM resistance in isolation; comprehensive syntheses integrating TLS resistance advances—and critically, cross-disease comparisons of genetic architecture, transcriptional reprogramming, and defense signaling—are notably scarce. Furthermore, the translational pipeline—from gene discovery and functional validation to deployment in marker-assisted or genome-edited breeding—lacks systematic evaluation. Here, we provide a focused, cucumber-centered review that (i) synthesizes recent progress in mapping QTLs and GWAS loci, and characterizing key resistance-associated gene families (such as NLRs, RLKs, PR genes) conferring resistance to PM, DM, and TLS; (ii) integrates transcriptomic, epigenomic, and proteomic evidence to delineate conserved versus pathogen-specific host responses; (iii) highlights breakthroughs and unresolved questions in TLS resistance research, including the roles of novel susceptibility factors and non-canonical immune regulators; and (iv) critically assesses bottlenecks in translating resistance genes into practical breeding outcomes—such as linkage drag, functional redundancy, and genotype-by-environment interactions—and proposes empirically grounded strategies for accelerating molecular design of multi-disease-resistant cultivars. Collectively, this review aims to bridge fundamental insights with applied breeding goals, offering a conceptual and strategic framework for integrated management of foliar fungal diseases and the development of durable, broad-spectrum resistance in cucurbits. Full article

Plant architecture is a critical agronomic trait in watermelon (Citrullus lanatus), with vine length directly influencing planting density, light interception, and field management efficiency. Short-vine forms have become important agronomic targets in breeding due to their advantages of high-density planting, efficient light utilization, and simplified field management. In this study, a dwarf mutant, designated PKH207, was identified from an ethyl methanesulfonate (EMS)-mutagenized population of the watermelon inbred line G42. The mutant exhibited significantly reduced plant height and shortened internodes due to decreased cell expansion in stem tissues. Genetic analysis indicated that the dwarf phenotype in PKH207 is controlled by a single recessive gene, which was named Cldw2 (Citrullus lanatus dwarf mutant 2). Using a population of 558 F₂ plants, bulked segregant analysis sequencing (BSA-seq) and linkage mapping delimited the causal locus to a 540.6 kb region on chromosome 10. Within this interval, a single-nucleotide polymorphism (SNP) mutation was identified in the gene ClG42_10g0100600, encoding an α-tubulin, and this gene was determined to be the candidate gene for the dwarf phenotype. Transcriptome analysis revealed that this mutation significantly disrupts key biological processes, including cell wall biosynthesis, microtubule cytoskeleton organization, and auxin signaling pathways, contributing to the dwarfism phenotype. This study identifies a novel dwarfing allele in cucurbits and provides a direct molecular target for breeding compact watermelon cultivars suited to high-density production. Full article

The photophysical processes and photochemical reactions of 1,4-di(azastyryl)benzene (1) derivative {[(E,E)-1](ClO₄)₂} were investigated by absorption, luminescence, and laser kinetic spectroscopy in the water solution. The observed photo processes include dimerization, E-Z isomerization, and intersystem crossing to the triplet state, as well as the complexation [(E,E)-1](ClO₄)₂ with cucurbit[7]uril (CB[7]). The [(E,E)-1](ClO₄)₂ dye dimerization was shown to be energetically more favorable in the excited state than in the ground state. The reversible photoinduced migration of the dye dication in the CB[7] cavity takes place as a result of partial exit of the [(E,E)-1]²⁺ from the cavity and its subsequent conversion to the (E,Z)-isomer in the excited state, which undergoes conversion to the initial complex of {[(E,E)-1]@CB[7]}²⁺ after returning to the ground state. This photoprocess is of interest in relation to the scientific problem of designing photocontrolled supramolecular machines. Full article

Background: C2H2 zinc finger proteins (C2H2-ZFPs) are one of the largest transcription factor families in plants and play vital roles in plant organ development and patterning, seed germination, and fruit ripening, as well as responses to biotic and abiotic stresses. Although widely studied in many species, the genome-wide characterization of the C2H2-ZFP family in watermelon (Citrullus lanatus) remains lacking. Methods: In this study, we identified 96 ClZFP genes in the watermelon genome and analyzed their chromosomal positions, gene structures, conserved motifs, and expression profiles. A tissue-specific expression analysis of 12 representative ClZFP genes revealed diverse and organ-preferential expression profiles, indicating functional differentiation during development. Results: Under abiotic stress treatments, four genes were significantly downregulated under drought, while one gene was strongly induced; six genes were inhibited and three genes were activated under low temperature; and most tested genes were upregulated at 72 h under salt stress, with one gene continuously induced throughout the treatment period. Key ClZFP members such as ClZFP36 and ClZFP72 showed specific and strong induction under drought and salt stress, respectively. Conclusions: These results indicate that ClZFPs may be involved in the tolerance of watermelon to various abiotic stresses. This study not only clarifies the evolutionary and expression characteristics of the ClZFP family in watermelon but also provides candidate genes for the genetic improvement of stress tolerance in cucurbit crops. Full article

Sechium edule (Cucurbitaceae), commonly known as chayote, which is a cucurbit of economic relevance, has experienced higher incidence of wilting from Phytophthora capsici in Mexican commercial fields during heavy rainfall. The infection process of this oomycete on chayote stems at the anatomical level had not been documented. This study characterized histological changes in chayote stems infected with P. capsici. Plants were inoculated at the stem base with P. capsici mycelial plugs, while controls received sterile plugs. Stem samples collected at 8, 12, 16, 22, and 30 days post-inoculation were processed and stained using safranin O–fast green. Microscopic observations showed progressive anatomical alterations. At 8 dpi, hyphae appeared in cortical parenchyma and epidermis, with phenolic compound accumulation. By 12 dpi, stromata and sporangia were visible in vascular and cortical tissues, with tyloses formation. At 16 dpi, cell wall collapse and xylem colonization became evident. These effects intensified at 22 and 30 dpi, with tissue degradation and an abundance of hyphae. Control stems maintained intact structures. Macroscopically, plants remained asymptomatic until 12 dpi, when brown lesions appeared. By 22 dpi, leaf yellowing and stem necrosis were observed, leading to plant death by 30 dpi. The results demonstrate the rapid colonization of chayote tissues by P. capsici, and its impact on vascular integrity. This study provides knowledge for future research on host resistance and disease management in chayote crops. Full article

Background: PYR/PYL/RCAR proteins are core abscisic acid (ABA) receptors that play essential roles in ABA signal transduction, plant growth and development, and abiotic stress responses. However, the PYL gene family in watermelon (Citrullus lanatus) has not been systematically characterized, limiting our understanding of ABA-mediated stress adaptation in this economically important crop. Methods: A genome-wide analysis was performed to identify ClPYL genes in watermelon using a hidden Markov model search. Phylogenetic relationships were reconstructed using the maximum likelihood method. Segmental duplication events were analyzed using synteny analysis. Conserved motifs, gene structures, and promoter cis-acting elements were characterized using MEME and PlantCARE. Expression profiles under drought, salt, and cold stresses were examined by quantitative real-time PCR (qRT-PCR) with three biological replicates. Results: In this study, 15 ClPYL genes were identified in watermelon through genome-wide analysis. Phylogenetic reconstruction classified these genes into four subfamilies, with subfamily II being exclusively present in cucurbits—a lineage-specific feature not observed in Arabidopsis. Synteny analysis revealed eight segmental duplication events involving members of subfamilies I, III, and IV, while subfamily II members were not associated with these duplications. Members within the same subfamily share similar exon-intron structures and conserved motifs. Promoter analysis revealed that ClPYL genes are enriched with various cis-acting elements associated with hormone signaling and abiotic stress responses. Expression profiling demonstrated that ClPYL genes exhibit diverse and dynamic expression patterns under drought, high-salinity, and cold stresses. Notably, genes such as ClPYL5 under drought, ClPYL02 under salt, and ClPYL15 under cold stress displayed persistent stress-responsive expression. Conclusions: These findings reveal the evolutionary conservation and diversification of the PYL family in watermelon and provide a set of candidate genes for functional studies aimed at dissecting ABA-mediated stress adaptation. This work establishes a genomic framework for developing stress-resilient watermelon varieties through molecular breeding. Full article

Zucchini tigre mosaic virus (ZTMV; Potyvirus pepotigris), which infects wax gourd (Benincasa hispida), was first identified in Taiwan in 2017 and designated ZTMV-TW. In this study, mild strains of ZTMV-TW were generated by modifying the pathogenicity factor HC-Pro to develop cross-protection strategies for cucurbit crops. A full-length infectious cDNA clone of ZTMV-TW was cloned in pCAMBIA1304 under the control of the CaMV 35S promoter (ZTMV-TWic). ZTMV-TWic induced typical potyvirus particles, cytoplasmic inclusion bodies, and severe symptoms in wax gourd, pumpkin, and zucchini plants. Conserved motifs of HC-Pro were mutated to generate four single mutants (F7I, R181I, F206L, and D397N) and three double mutants (F7I+F206L, R181I+D397N, and F206L+D397N). Mutants R181I and R181I+D397N caused mild or no symptoms in zucchini, while D397N and F206L+D397N were mild in wax gourd. Cross-protection assays showed that R181I and R181I+D397N provided complete protection against ZTMV-GFP in zucchini, whereas D397N and F206L+D397N conferred high protection in wax gourd. These results demonstrate the feasibility of host-specific mild strain selection for effective ZTMV cross-protection. Full article

The Lateral Organ Boundaries Domain (LBD) gene family encodes plant-specific transcription factors that play pivotal roles in growth, development, and stress responses. However, a comprehensive genome-wide analysis of the LBD family in watermelon (Citrullus lanatus) has not been conducted until now. In this study, we identified 39 ClLBD genes using the latest watermelon reference genome and systematically analyzed the function of ClLBD2 in root development. These ClLBDs are unevenly distributed across 10 chromosomes except Chr4. Evolutionary analysis grouped the gene family members into six subgroups: Class I (a–e) and Class II. Physicochemical properties and gene structure analysis showed that the ClLBD protein members are tightly conserved. In the promoter regions of ClLBD genes, we identified abundant cis-acting regulatory elements related to abiotic stress and hormone responses. Through RNA-seq analysis from a cucurbit database, we found that several ClLBD genes showed high relative expression in roots, with ClLBD2 being the most highly expressed. Since its subfamily includes AtLBD25, a known root development-related gene, we hypothesized that ClLBD2 might be involved in root development. To validate this, ClLBD2-edited roots were generated using the CRISPR-Cas9 system and Agrobacterium rhizogenes-mediated transformation. Compared to the wild type, the ClLBD2 edited roots exhibited significant reduction in taproot length and lateral root numbers, indicating that ClLBD2 may regulate root development. This study provides the first comprehensive analysis of the LBD gene family in watermelon, offering valuable insights for evolutionary and further functional studies of ClLBD genes. Full article

Cucurbitaceous plants comprise a wide range of economically important vegetable and fruit crops. In this study, Alternaria species associated with Cucurbitaceae were investigated using an integrative approach combining multilocus phylogenetic analyses and morphological characterization. Two novel species, Alternaria charantiicola sp. nov. and A. cucumicola sp. nov., were identified from Momordica charantia and Cucumis sp., respectively. In addition, five Alternaria species, namely A. zeae, A. lycopersici, A. sanguisorbae, A. pulvinifungicola, and A. solanicola, are reported for the first time from cucurbitaceous hosts. These findings expand the known species diversity of Alternaria associated with Cucurbitaceae in China and provide a taxonomic basis for the accurate diagnosis of Alternaria-related diseases in cucurbit crops. Full article

The melon fly, Zeugodacus cucurbitae (Coquillett), is recognized as a globally significant quarantine pest, and it ranks among the most destructive insect species infesting cucurbit and solanaceous crops. However, the molecular mechanisms governing reproductive regulation in female Z. cucurbitae remain poorly characterized, particularly those underlying the reproductive processes mediated by microRNAs (miRNAs). In this study, we firstly identified the ovary-specific gene ZcCTL-S1 in Z. cucurbitae via transcriptomic analysis, and subsequently predicted its targeted miRNAs using bioinformatics approaches. Among these miRNAs, overexpression or inhibition of miR-971-1 and miR-let-7 led to corresponding inverse changes in the transcriptional level of ZcCTL-S1. Notably, only miR-let-7 displayed markedly elevated expression levels in Z. cucurbitae ovaries. Further analyses confirmed that miR-let-7 exhibited a direct targeting relationship with ZcCTL-S1, via a combinatorial approach involving in vivo RNA immunoprecipitation, in vitro dual-luciferase reporter assays, and site-directed mutagenesis techniques. Phenotypic analyses showed that both knockdown of ZcCTL-S1 and overexpression of miR-let-7 significantly inhibited egg hatchability, ultimately compromising the female reproductive capacity of Z. cucurbitae. Collectively, these findings identify a novel miRNA-gene regulatory module in the reproductive development of Z. cucurbitae, and provide novel insights for the development of gene- or miRNA-based pest control strategies. Full article

Tomato leaf curl New Delhi virus (ToLCNDV) is a bipartite begomovirus (family Geminiviridae) originally isolated from tomatoes and later evolved to cross-infect cucurbit crops, causing severe economic damage in Asia and Europe. In this study, we sequenced and characterized complete genomes of two ToLCNDV isolates collected from Hebei (ToLCNDV-HB) and Jiangsu (ToLCNDV-JS) provinces of China infecting melon. We constructed infectious clones for ToLCNDV-HB and ToLCNDV-JS, which could systemically infect Nicotiana benthamiana, tomato, and four species of cucurbitaceous plants. Notably, ToLCNDV-HB induced more severe symptoms and accumulated higher viral DNA and protein accumulation than ToLCNDV-JS in N. benthamiana, melon, and bottle gourd. Sequence analysis showed that sequence variations are present only in AV2, AC1, and AC4. However, only the AV2 ORF from ToLCNDV-HB was more efficient than that from that ToLCNDV-JS in enhancing potato X virus’s pathogenicity and suppressing post-transcriptional gene silencing (PTGS). An AV2-swapping experiment between ToLCNDV-HB and ToLCNDV-JS confirmed its vital role in determining the differential pathogenicity. Further evidence shows that virions from both clones are mechanically transmissible. This is the first report comparing the differential pathogenicity of two Chinese ToLCNDV isolates in cucurbits. The AV2 protein, a key pathogenicity determinant, represents a potential target for breeding ToLCNDV-resistant cucurbit varieties. Full article

Phytophthora capsici, an invasive oomycete pathogen causing blight in crops like cucurbits, tomatoes, and peppers, has led to significant economic losses. Due to the limitations of conventional control methods, research has focused on effective and eco-friendly biocontrol alternatives. The bacterial strain LT-22, identified as Bacillus velezensis, exhibits broad-spectrum antifungal activity and plant growth-promoting potential. This study investigated the biocontrol efficacy of volatile organic compounds (VOCs) from strain LT-22. LT-22 VOCs strongly inhibited P. capsici PC153 growth in vitro and reduced disease symptoms in pepper fruits. Microscopic observations showed that LT-22 VOCs caused significant morphological changes in P. capsici PC153 mycelium by disrupting cell wall and membrane integrity. The treatment increased malondialdehyde (MDA) levels and reduced cellulose content, further indicating that LT-22 VOCs compromise cell integrity to exert antifungal effects. Furthermore, 2-methylbutanoic acid was identified as the primary antifungal VOC, with an EC₅₀ value of 0.095 µL/mL against P. capsici PC153, lower than the reported plant-derived compounds. Together, these results indicate that strain LT-22 and its VOCs, especially 2-methylbutanoic acid, have significant potential as an effective biocontrol agent for managing Phytophthora blight. Full article