Heterologous over expression of blueberry VcBR6OX1 triggers seedless/low-seed tomatoes via elevatingendogenous GA4, reshaping multi-hormone homeostasis and modulating hormone signal transductionpathways to regulate seed development as confirmed by transcriptome analysis. If highlight marking is needed, it is shown as follows: （1） Heterologous overexpression of the blueberry VcBR6OX1 gene can induce seedless or low-seedtomato fruits; （2） The endogenous gibberellin GA4 in transgenic plants is significantly increased, and the dynamichomeostasis of the multiple hormone network is reconfigured （3） Transcriptome analysis reveals that BR6OX1 affects seed development by regulating the hormonesignal transduction pathway. Blueberries (Vaccinium spp.) have attracted widespread attention due to their unique flavor and high antioxidant activity. However, the high seed content of some blueberry cultivars affects their texture and processing costs. The development of seedless or low-seed cultivars is essential for improving fruit quality and economic benefits. This study used bioinformatics, genetic transformation, and transcriptomic analysis to investigate the role and regulatory mechanisms of the blueberry Brassinosteroid-6-oxidase 1 (BR6OX1) gene in the formation of seedless fruits. The results revealed that the BR6OX1 gene in blueberries encodes an unstable hydrophilic protein with a conserved cytochrome P450 superfamily domain and is highly evolutionarily similar to that in closely related species. The introduction of the BR6OX1 gene into tomatoes revealed that its overexpression significantly affects the growth and development of tomato plants, resulting in seedless or low-seeded fruits. Endogenous hormone analysis revealed that the gibberellic acid (GA4) content significantly increased in the transgenic tomato plants, whereas the auxin (IAA) and abscisic acid (ABA) contents exhibited differential changes at different developmental stages. Further transcriptome analysis of the transgenic plants revealed that BR6OX1 overexpression significantly affects plant hormone signaling pathways, particularly by causing significant changes in the expression of genes related to hormone synthesis and signaling, such as those encoding auxin, gibberellin, abscisic acid, and ethylene. These results suggest that the BR6OX1 gene may influence fruit set by regulating the balance of plant hormones. This study provides an important theoretical basis for developing seedless blueberries and lays the foundation for the application of this gene in the improvement of fruit quality.
Fruit growth and development are generally initiated following successful pollination and fertilization. Seedless chestnut rose (Rosa sterilis), an elite promising fruit tree for both edible and medicinal purposes due to the extremely high vitamin C and superior quality, exhibits a naturally parthenocarpic character, however the underlying mechanism has been still unclear so far. Currently, gibberellins (GAs) were justified as the key hormone for parthenocarpy induction in seedless chestnut rose by endogenous hormone analysis and exogenous plant growth regulator (PGR) application. In total, 43 members of the GA oxidase gene family (RsGAoxs) were systematically identified and characterized based on genome-wide analysis of seedless chestnut rose. On the basis of transcriptomic analysis, overexpression experiments in tomato, as well as virus-induced gene silencing (VIGS) assay in seedless chestnut rose, RsGA3ox9 was substantially justified to be involved in the parthenocarpic fruitsetting of this species. Transcription factors RsMYB3, RsMYB8, and RsMYB73 were proven to positively regulate the expression of RsGA3ox9. Further, yeast two-hybrid (Y2H) and luciferase complementation assay illuminated that RsMYB8 and RsMYB73 may interact, leading to upregulating RsGA3ox9. Thereby, RsGA3ox9 substantially regulates parthenocarpy of seedless chestnut rose, and RsMYB8-RsMYB73 complex promotes parthenocarpic fruitsetting by upregulating RsGA3ox9, which may facilitate the seedless fruit breeding in chestnut rose (Rosa roxburghii Tratt.), as well as provide novel insights for better understanding the mechanism underlying the parthenocarpic fruitsetting in fruit species.
Embryo rescue is a crucial technique for developing new seedless grape germplasm; however, its current efficiency remains suboptimal. Optimizing the culture medium is essential for the success of embryo rescue, as it directly influences the development and germination of in vitro embryos. Therefore, this study systematically investigated the effects of parental genotypes and the addition of zeatin (ZT) to the culture medium on the efficiency of embryo rescue, using four self-pollinated maternal parents and 23 seedless×seeded (or seedless) cross combinations. The results showed that among the four self-pollinated parental lines, hybrid ovules exhibited the highest development rate in the ER medium, while a higher proportion of normal plantlets was obtained in the MM3 medium. Although the addition of ZT at various concentrations did not significantly enhance the embryo development rate in the self-pollinated maternal parents, it significantly improved germination outcomes: compared to the control, the rate of normal plantlet formation increased by 8.84-19.03%, while the proportions of abnormal plantlets and ungerminated embryos were significantly reduced. Further validation in hybrid combinations revealed that the addition of an appropriate concentration of ZT significantly increased both embryo development and plantlet formation rates in both MM3 and ER media. Specifically, in the MM3 medium supplemented with 0.5 mg L-¹ ZT, the hybrid combination 'Huozhoucuiyu × Yan73' achieved the highest embryo development rate (63.33%) and plantlet formation rate (26.67%). Across the 23 hybrid combinations, the average embryo development rate reached 39.57%, yielding a total of 1,554 hybrid progeny. Parental screening indicated that 'Huozhoucuiyu' and 'Ruby Seedless' performed excellently as maternal materials, while 'Yan73', 'Italy', and 'Ruidukemei' were suitable as paternal materials. Using the KASP_VviAGL11 molecular marker, 290 potential seedless lines were identified from 420 hybrid progeny across six combinations, accounting for 69.05% of the total. This study confirms that the appropriate addition of ZT to the culture medium significantly enhances the efficiency of embryo rescue breeding in seedless grapes, providing a practical foundation for establishing a highly efficient and stable embryo rescue system.
Grape seedlessness, a pivotal agronomic trait, is governed by intricate molecular mechanisms that remain partially elucidated. In this study, we identified VvmiR408 as a key regulator targeting VvAGL61 (a class D MADS-box gene) through RLM-RACE and PPM-RACE analysis, with cleavage validation at the 10th nucleotide of the miR408 complementary site, and uncover VvmiR408-VvAGL61 is a pivotal regulatory module during grape seed development, with a striking antagonism of spatial-temporal expression profiles between VvmiR408 and VvAGL61 in this process: VvmiR408 peaked during seed abortion in the seedless cultivar 'Jingkejing' (40 DAF, 3.8-fold increase), while VvAGL61 dominated during seed development in the seeded 'Wink' (40 DAF, 11-fold elevation), indicating VvmiR408 promoting seed abortion in seedless berries while VvAGL61 enhances seed development. This hypothesis was further validated by transgenic tobacco overexpressing VvMIR408, which exhibited a significant reduction in both seed number and silique size, through the down-regulation of NtAGL61, the tobacco ortholog of VvAGL61. Collectively, we propose an interaction model of the miR408-AGL61 module mediating seed development and abortion in grapes and tobaccos. This model highlights key target sites for molecular breeding aimed at producing high-quality seedless grapes.
BACKGROUND: Grapevine (Vitis vinifera L.) is one of the world’s most important fruit crops, but its production is increasingly challenged by climate change and the rising incidence of spring frost, particularly in sensitive cultivars like ‘Thompson Seedless’. The selection of an appropriate trellis training system and the precise timing of management operations, particularly pruning timing, are key strategies for mitigating frost damage. This study aimed to evaluate the interactive effects of year (2023 and 2024 growing seasons), trellis training system (I, T, and Y), and sampling time (March 5, March 25, April 14, and May 5) on the physiological and biochemical indices related to spring frost tolerance in ‘Thompson Seedless’ grapevine. RESULTS: The study was conducted as a split-plot in time within a randomized complete block design. Analysis of variance revealed that the main effects of year, sampling time, and training system were significant (p < 0.01) for all measured indices, including frost tolerance (assessed by electrolyte leakage and budbreak assays), relative water content (RWC), soluble proteins, starch, soluble carbohydrates, proline, malondialdehyde (MDA), hydrogen peroxide (H2O2), and total phenols. Among the training systems, the Y and T systems demonstrated superior performance in both years. These systems were associated with the highest levels of soluble protein (14.80 and 16.16 mg/g FW, respectively), total phenols (12.25 and 12.07 mg GAE/g FW), and frost tolerance as measured by electrolyte leakage (LT50 of Y=-12.68 °C and T=-10.90 °C). Conversely, the I system showed greater sensitivity, marked by increased MDA content (7.34 nmol/g FW) and reduced frost tolerance in the budbreak assay (LT50 of -7.23 °C). CONCLUSIONS: The Y and T training systems enhance spring frost tolerance in ‘Thompson Seedless’ grapevine by improving the antioxidant defense system and promoting the accumulation of osmolytes. Our findings suggest that the Y and T systems, respectively, are the most effective treatments for improving spring frost tolerance by enhancing the physiological status and reducing oxidative stress in grapevine buds. These systems are recommended as a sustainable management strategy in vineyards prone to spring frost.
Ougan (Citrus suavissima Hort. et Tanaka) is valued for its distinctive sweet-bitter flavor and nutritional properties; however, tissue-resolved metabolic differences between two cultivar forms (seeded and seedless) of Ougan (C. suavissima) remains poorly understood. In this study, a comprehensive UPLC-MS/MS-based metabolomic analysis was conducted on peel (SP and NP), pulp (SF and NF), segment membrane (SM and NM) and seed tissues (SS, from seeded fruit only) of seeded and seedless Ougan fruits. A total of 1333 metabolites were annotated, with flavonoids (48.53%) and phenolics (12.25%) representing the predominant compound classes. Tissues specificity was the primary determinant of metabolic variation, with peel and segment membrane tissue showing relatively high abundance (fold change ≥ 2, |Log2FC| ≥ 1) of phenylpropanoid- and flavonoid-derived metabolites. Comparative analysis between seeded and seedless tissues revealed significant modulation of phenylpropanoid biosynthesis, flavonoid biosynthesis, phenylalanine metabolism, and related secondary metabolite pathways. Seeded tissues showed a higher relative abundance of selected flavonol glycosides (6-hydroxykaempferol-3,6-O-diglucoside), hydroxycinnamic acid derivatives, and santhocyanin-related compounds, whereas seedless tissues showed higher relative abundance of selected flavanones and malonylated flavonoid glycosides. Seeds were characterized by high limonin content, consistent with limonoid-associated bitterness chemistry. Overall, our findings provide a tissue-resolved metabolomic framework for understanding quality-associated secondary metabolite variation in mature Ougan fruit.
The evolution of seeds was a critical transition in plant evolution, but how ancestral seedless development was modified to form the first seed is only partly-answered through comparative morphology or the fossil record. We investigate seed origins by quantifying gene network conservation between seeds and seedless plant reproductive organs. Characterizing reproduction in the homosporous fern Ceratopteris richardii as a proxy for ancestral seedless reproduction, we create a gene expression atlas of fern diploid and haploid reproductive organ development and test for enrichment of these genes in Arabidopsis thaliana. Here we show ovule gene networks are enriched in genes regulating post-fertilization development of the fern haploid egg chamber (archegonium), a subset of which also show enrichment in sporophyll primordia, suggesting a mechanistic model to explain the origin of the ovule from a sporangium-bearing axis whereby gene networks in the ancestral post-fertilization archegonium became heterotopically expressed during development of the sporangium-bearing axis.
To investigate the effects of different seedless treatments on grape coloring and fruit quality, Vitis vinifera × Vitis labrusca cv. 'Jumeigui' were treated with different concentrations of forchlorfenuron (CPPU) (0.5, 1 and 1.5 mg/L), thidiazuron (TDZ) (0.5, 1 and 1.5 mg/L), and 6-benzyladenine (6-BA) (10, 20 and 30 mg/L) in combination with 18 mg/L gibberellic acid (GA3) during the seedless-fruit-setting period. After the grapes ripened, multiple quality indicators were measured to analyze and evaluate the effects of different treatments on the fruit coloration and quality of 'Jumeigui' grapes. The results showed that increasing concentrations of CPPU and TDZ gradually reduced the comprehensive fruit quality of 'Jumeigui' grapes. The treatments with 18 mg/L GA3 + 0.5 mg/L CPPU/TDZ were relatively effective in improving the comprehensive quality of 'Jumeigui' grapes. With increasing concentrations of 6-BA, the comprehensive effect initially increased and then decreased. The treatment with 18 mg/L GA3 + 20 mg/L 6-BA resulted in a soluble solids content of 20.03% and a coloring index of 4.10, demonstrating the best overall improvement in the comprehensive quality of 'Jumeigui' grapes. Based on practical production considerations, it is recommended to apply 18 mg/L GA3 + 20 mg/L 6-BA during the seedless-fruit-setting period of 'Jumeigui' grapes to enhance coloring effects and improve fruit quality.
Gibberellin (GA)-based seedless cultivation is widely used in the skin-edible interspecific table grape (Vitis labruscana × Vitis vinifera) 'Shine Muscat', yet when and how GA treatment reshapes fracture-type texture during berry development remains unclear. This study aimed to identify developmental stages and tissue/cell-wall features associated with GA-dependent differences in berry fracture behavior. We integrated intact-berry fracture testing at harvest (DAFB105), quantitative histology of pericarp/mesocarp tissues just before veraison (DAFB39) and at harvest, sequential cell-wall fractionation assays targeting pectin-rich (uronic acid) and hemicellulose/cellulose-related pools at cell division period, cell expansion period and harvest, and stage-resolved RNA-Seq across the same three developmental stages. GA-treated berries had a larger diameter and showed a higher fracture load and a lower fracture strain than non-treated berries at harvest, while toughness did not differ significantly. Histology revealed thicker pericarp tissues and lower mesocarp cell density in GA-treated berries, together with increased cell-size heterogeneity and enhanced radial cell expansion. Cell wall analyses showed stage-dependent decreases in uronic acid contents in water-, EDTA-, and Na2CO3-soluble fractions in GA-treated berries. Transcriptome profiling indicated GA-responsive expression of putative cell expansion/primary-wall remodeling genes, EXORDIUM and xyloglucan endotransglucosylase/hydrolases, at DAFB24 and suggested relatively enhanced ethylene-/senescence-associated transcriptional programs together with pectin-modifying related genes, Polygaracturonase/pectate lyase and pectin methylesterase, in non-treated mature berries. Collectively, GA treatment modifies mesocarp cellular architecture and pectin-centered wall status in a stage-dependent manner, providing a tissue- and cell wall-based framework for interpreting fracture-related texture differences under GA-based seedless cultivation in 'Shine Muscat'.
This study evaluated the combined effects of grafting and deficit irrigation (DI) on soil attributes, vegetative growth, yield components, fruit quality, and water productivity of 'Crimson Seedless' grapevines under semiarid conditions. It was hypothesized that the DI could enhance crop water productivity and fruit quality, especially when integrated with grafting, without a significant reduction in fruit yield. DI included five irrigation treatments: full irrigation (control), 75% of full irrigation over the season (D1), 75% of full irrigation except during the berries enlargement stage (principal growth stage 7, or BBCH 71-79), received water equivalent to the control (D2), 50% of full irrigation (D3), and 50% of full irrigation except during the berries enlargement stage, received water equivalent to control (D4), with and/or without grafting. The grapevines under deficit irrigation produced the highest crop water productivity, fruit soluble solid content (SSC), and total anthocyanins without significant impacts on fruit yield, except for D4 (severe deficit). Deficit irrigation applications saved 25%, 13%, 50%, and 26% of the water used for D1, D2, D3, and D4, respectively, compared with the control, resulting in decreased power consumption during vineyard irrigation and, subsequently, reduced irrigation costs. Moreover, soil porosity and hydraulic conductivity remained unaffected. In addition, grafted grapevines produced lower vegetative growth parameters but improved most fruit quality parameters without significantly affecting fruit yield. The present study confirmed that deficit irrigation could effectively save water and improve fruit quality without affecting fruit yield for grapevines in arid and semiarid regions. Furthermore, grafting on specific rootstock should be used as a practical approach for managing water deficit conditions.
The seed-mediated solution growth is largely reported for obtaining chiral noble metal nanostructures, but multistep growth procedures and delicate seed dependence increase its complexity. Herein, we report a seedless, solution-based synthetic strategy for obtaining Ag-Pt hollow nanostructures with chiral nanoarrays on the surface, where enantiomers of 2-deoxy-d-/l-ribose and thymine are utilized as chiral comolecule inducers. By simply changing the feeding sequence, both hollow nanospheres and nanotubes can be synthesized due to the differentiated formation of thymidine as a key intermediate. In situ-formed Ag-rich nanoparticles and nanowires act as sacrificial templates for subsequent Pt growth, leading to hollow nanostructures with Ag-rich inner and Pt-rich chiral surfaces. The growth mechanism can be extended to guide the synthesis of similar chiral Ag-Ir hollow nanostructures. The chiral Ag-Pt hollow nanostructures, especially nanotubes, are fully functional for electrochemical enantioselective detection of tryptophan enantiomers. Our work provides a feasible strategy for fabricating catalytically active noble metals with hierarchical chiral nanostructures.
Crimson Seedless is a globally important table grape cultivar valued for its color, marketability, and nutritional quality. However, enhancing berry coloration and biochemical quality remains a major challenge, especially under fluctuating environmental conditions. In this context, the individual application of nanoparticles or molasses as natural organic stimulants may offer an effective. This study hypothesizes that foliar application of zinc oxide nanoparticles (ZnO NPs) and molasses, either individually or in combination, would increase yield, berry coloration, and antioxidant-related biochemical parameters compared with those of the untreated control. The experiment included eight treatments applied to five grapevines per treatment via a randomized complete block design (RCBD) over two consecutive seasons (2023-2024), and the effects of ZnO NPs at 10, 50, and 100 mg L- 1, applied alone or in combination with molasses at 1.5 cm³ L- 1, on productivity, cluster traits, anthocyanin accumulation, and antioxidant-related enzymes were evaluated. In terms of productivity, cluster quality, and berry coloration, the treatment with ZnO NPs plus molasses followed closely by ZnO NPs alone surpassed the nontreated vines. The 10 mg L- 1 ZnO NPs + molasses treatment was superior for most of the studied parameters. For example, the total yield increased by approximately 8.9-11.4%, the total soluble solid (TSS) content increased by 48.4-43.8%, the firmness increased by 8.1-12.0%, and the acidity decreased by 16.3-15.4% compared with those of the control treatment in both seasons. Additionally, the same treatment resulted in the greatest increase in anthocyanin content (104.3-73.4%) and PAL activity (48.4-58.1%) compared with those of the control in both seasons. The application of 10 mg L-1 ZnO NPs + 1.5 cm3 L-1 molasses once at the veraison stage increased the grape yield, color, and biochemical quality. While a single-stage application was effective, further studies could explore multistage applications or alternative timings to optimize the results.
Table grapes are widely consumed fruits, and their quality is largely determined by aroma, texture, and the accumulation of health-promoting compounds such as flavonoids. In this study, we systematically compared the edible quality and molecular basis of flavonoid biosynthesis among three major table grape cultivars: Crimson Seedless (CRS), Red Globe (RG), and Shine Muscat (SM). An integrated approach combining physicochemical assays, Gas chromatography-ion mobility spectrometry (GC-IMS)-based volatile profiling, and transcriptome sequencing (RNA-seq) was employed. Among the three cultivars, SM exhibited superior fruit quality, characterized by the highest firmness, total soluble solids, ascorbic acid, total phenolic content, and flavonoid content, whereas CRS showed the highest titratable acidity. Volatile compound analysis revealed distinct aroma profiles among the cultivars. SM was enriched in ethanol and 2-methylbutanal, contributing sweet and fruity notes, while CRS contained higher levels of C6 aldehydes, such as hexanal and (E)-2-hexenal, which are associated with green and leafy aromas. RG exhibited a relatively simpler volatile profile with lower overall abundance. Transcriptome analysis identified 20 differentially expressed genes involved in the flavonoid biosynthetic pathway, including PAL, C4H, 4CL, CHI, F3H, F3'H, and DFR, of which ten were significantly upregulated in SM. Eight of these genes showed strong positive correlations (r > 0.8) with flavonoid content. These results provide a comprehensive understanding of the metabolic and genetic mechanisms underlying cultivar-specific quality traits and identify promising candidate genes for breeding table grapes with enhanced flavor and health-promoting properties.
Near-infrared (NIR) wavelengths offer a powerful approach for non-invasive physiological monitoring due to the deep tissue penetration and ability to detect various endogenous molecules such as hemoglobin species, water, and lipids. Herein, we demonstrate a high-speed, non-contact photoplethysmography (PPG) system based on indium arsenide (InAs) colloidal quantum dots (CQDs). To this end, a seedless injection-based one-pot method was devised to synthesize monodisperse NIR InAs CQDs. This scalable approach enables precise bandgap tuning from 1.53 to 1.09 eV, aligning with the absorption spectra of hemoglobin and oxyhemoglobin. Furthermore, the proposed CQD-based PPG system is integrated into a real-time acquisition platform. Exercise-induced desaturation tests show that the CQD-based PPG system exhibits consistent oxygen saturation rate (SpO2) trends compared to commercial oximeters, exhibiting a considerable agreement of 99.76% (SpO2 range: 90%-92%). The system also shows reliable operation with a bandwidth up to 2.5 kHz under multi-lock-in detection.
In this study, the Fe2O3 material was synthesized by green chemistry using seedless lemon peel extract. The structural characteristics of Fe2O3 were analyzed through SEM, FTIR, XRD and BET analytical methods. Factors affecting the adsorption of anionic dyes (Congo Red, Methyl Red, Methyl Orange) were also evaluated, such as temperature, pH, time, Fe2O3 dosage and dyes' concentration. It was shown that the material has a heterogeneous cubic shape with iron and oxygen elements at the ratio of 43% and 12%. The crystal faces (120), (220), (400), (018), the material was identified as γ- Fe2O3 with a characteristic spinel structure with tetrahedral and octahedral shapes. The free functional groups on the surface are OH, Fe-O, with 635.58 cm-1 was attributed to the octahedral and tetrahedral sites of the Fe-O band. Temperature is the least influential factor and value was 30 °C. It can be seen that γ-Fe2O3 is the good adsorbent in the pH4-pH6 range, for 60 to 90 min, at dosage of 0.5 to 2 g/L and a dyes' concentration of 200-300 mg/L. The maximum adsorption capacities of MO, CR, and MR were recorded 31.349 mg/g, 49.071 mg/g, and 119.705 mg/g, respectively. The adsorption mechanism has also been predicted and shown to depend on the type of dye with different interaction and adsorption capabilities. This helps the adsorption capacity of Fe2O3 material from lemon peel extract to be more diverse and applied more widely.
Stigma exsertion was largely eliminated during tomato domestication to promote self-pollination and secure yield. Nevertheless, exserted stigmas can prevent self-pollination and thus have potential utility for hybrid seed production by reducing costs and improving seed purity. Despite this promise, practical applications have remained limited due to the instability of the trait and low hybrid seed yields. Here, we combined stigma exsertion conferred by Style2.1 with parthenocarpy induced by the iaa9-3 mutation to develop an elite line, APi7-4-5. This line consistently displayed long stigma exsertion together with strong parthenocarpy. Morphological and reproductive analyses demonstrated that APi7-4-5 is a highly effective maternal line for hybrid seed production without emasculation, owing to its unique features: (i) complete inhibition of self-pollination under both greenhouse and field conditions, and (ii) high receptivity to pollen before anthesis, supporting efficient pollen germination and tube growth. In addition, the presence of Style2.1 in the F₁ generation further contributes to hybrid performance by preventing self-pollination and thereby enhancing parthenocarpic fruit set in untouched flowers. This semi-dominant effect of Style2.1 leads to a higher proportion of seedless fruits and improved uniformity in F₁ hybrids. Collectively, these results establish a feasible strategy for hybrid tomato seed production without emasculation by integrating iaa9-3-mediated parthenocarpy with Style2.1-regulated stigma exsertion. This approach provides a foundation for reducing hybrid seed production costs while improving seed yield and genetic purity in tomato. The online version contains supplementary material available at 10.1007/s11032-026-01642-z.
Quantum dots are high-potential materials for a wide range of applications, particularly in the infrared spectral range, including telecommunications, security, sensing, photovoltaics, and bioimaging. The size and chemical composition of semiconductor quantum dots determine their optoelectronic properties. While II-VI and IV-VI quantum dots are well-studied, the colloidal synthesis of infrared-active III-V quantum dots such as InAs, which are compliant with the European Union directive for restriction of hazardous substances, remains underdeveloped. In particular, the synthesis of larger InAs quantum dots is challenging due to the strong covalent character of In-As bonding, limited control over precursor reactivity, and complex growth pathways. Here we show the synthesis of large, near-bulk InAs quantum dots using atomic clusters as precursors. All nanostructures are synthesized from 'green' commercially available precursors. These results extend the accessible size regime of colloidal InAs nanoparticles to diameters approaching 40 nm and establish a platform for their use in infrared technologies.
Grapevine cultivation in a Mediterranean environment is significantly influenced by climate conditions, which determine vine growth characteristics and berry quality, resulting in financial losses for growers. To address these issues and meet the export standards of Flame Seedless grapes, integrated strategies were adopted, including plastic covering along with foliar applications of 24-epibrassinosteroids and gibberellic acid. A split-plot experiment was conducted in 2024 and 2025, testing two gibberellic acid (GA3) regimes (one at 110 µL L-1 [ppm] applied at three stages and another at 20 µL L-1 applied at two stages), alongside various concentrations of foliar-applied brassinosteroid (BR) at 0, 0.5, 1.0, 1.5, and 2.0 µL L-1. The results indicated that the application of GA3 and/or 24-epibrassinosteroids significantly improved the quality of grape clusters and berries, including their chemical traits, color parameters, and the biochemical composition of grape leaves. Specifically, 20 µL L-1 GA3 enhanced berry firmness, berry adherence strength, coloration, and optimized total soluble solids (TSS), sugar, and anthocyanin levels, while decreasing the number of small berries, weight loss %, and titratable acidity. Meanwhile, the combined treatment of GA3 at 20 µL L-1 + BR at 2.0 µL L-1 treatment µL L-1 significantly increased cluster weight, cluster length, shoulder length, berry weight, berry diameter, berry force, berry firmness, CIRG, TSS, TSS/acidity ratio, total sugars, reducing sugars, and anthocyanin, while decreasing small berry incidence and acidity. The combination of GA3 at 20 µL L-1 with BR at 2.0 µL L-1 yielded the most significant improvements in berry and cluster dimensions and color intensity, as well as in the oxidative burst and antioxidant defense enzymes of fresh grape leaves. Overall, the results highlight that BR can be used as a partial substitute for GA3 under plastic covering as a promising tool to facilitate early harvest, improve grape bunch quality and berry quality, and reduce postharvest losses.
Understanding cultivar-specific nitrogen (N) responses is critical for managing grapevine nutrition. We compared growth, photosynthetic performance, and biochemical responses of two table grape cultivars, 'Red Globe' and 'Crimson Seedless', across four N levels (0, 25, 50, and 75 mM) over 75 days. A cultivar × N interaction heatmap revealed that interactions for most physiological traits were time-dependent: growth parameters diverged early (15 d), whereas photosynthetic pigments and membrane damage indicators became significant from 45 d onward. Soluble metabolites and antioxidant enzymes maintained significant cultivar × N interactions across nearly all time points, indicating consistently differentiated physiological traits between the two cultivars. PCA further revealed the physiological structure underlying this differentiation. 'Red Globe' was associated with growth, photosynthetic efficiency, and antioxidant coordination, whereas 'Crimson Seedless' was linked to stress indicators. 'Red Globe' maintained relatively stable growth, chlorophyll content, and photochemical efficiency across the N gradient, whereas 'Crimson Seedless' showed photoinhibition, membrane damage, and growth suppression under high nitrogen supply (50 and 75 mM), confirming its narrower N tolerance window. This differential sensitivity paralleled the contrasting antioxidant enzyme dynamics, which were sustained in 'Red Globe' but declined in 'Crimson Seedless', and which preceded the later divergence in photosynthetic and membrane traits. These results establish a physiological framework for cultivar-specific N management, highlighting the contrasting temporal strategies in growth, photosynthesis, and antioxidant defence between the two cultivars.
Drought stress severely restricts grape growth and yield. ERF105 is widely involved in plant developmental processes as well as responses to biotic and abiotic stresses. Nevertheless, existing studies of the ERF105 gene have primarily focused on cold and disease resistance, leaving its potential function in drought response largely unexplored. Therefore, investigating the role of ERF105 under drought conditions is crucial for understanding the molecular mechanisms of stress tolerance in grape and for breeding drought-resistant cultivars. A VvERF105 gene was cloned from drought-resistant Vitis vinifera cv. 'Thompson Seedless', followed by sequence analysis, subcellular localization assay, and expression pattern analysis. A dual-target gene editing vector of VvERF105 was subsequently constructed and transformed into embryogenic calli of 'Thompson Seedless' via Agrobacterium-mediated genetic transformation. Gene-edited and wild type (WT) grapes were subjected to drought treatment. The biological function of VvERF105 under drought stress was determined by observing the plant growth status and stomatal aperture, measuring the proline and malondialdehyde (MDA) contents, antioxidant enzyme activities, and the expression levels of drought-related genes. In addition, proteins interacting with VvERF105 were screened and verified using yeast two-hybrid, bimolecular fluorescence complementation (BiFC), and co-immunoprecipitation (Co-IP) assays. Their interaction was further confirmed using in vitro phosphorylation assays. VvERF105 is a stress-responsive gene localized in the nucleus. It responds to drought, cold, and high-temperature stresses and may act downstream of the ABA signaling pathway. VvERF105 mutant grapevine plants exhibited reduced resistance to drought stress. The edited lines exhibited smaller stomatal apertures, lower proline content, higher MDA content, and lower antioxidant enzyme activities compared to WT plants under drought stress. The expression levels of VvDREB2A, VvERD14, VvKIN2, VvNCED1, VvRD22, and VvRD29B were also significantly downregulated. VvSnRK1 was identified as an interacting protein of VvERF105 and interacts with it in a phosphorylation-independent manner. VvERF105 is a nucleus-localized stress-responsive transcription factor that positively regulates grapevine drought stress responses. Its disruption significantly reduces drought resistance. Moreover, it interacts with the kinase VvSnRK1 in a phosphorylation-independent manner to mediate drought stress signaling in grapevines. The aforementioned results provide valuable genetic resources for molecular breeding of grapevines with enhanced drought resistance.