The β-1,3-glucanase gene is widely involved in plant development and stress defense. However, an identification and expression analysis of the grape β-1,3-glucanase gene (VviBG) family had not been conducted prior to this study. Here, 42 VviBGs were identified in grapevine, all of which contain a GH-17 domain and a variable C-terminal domain. VviBGs were divided into three clades α, β and γ, and six subgroups A–F, with relatively conserved motifs/domains and intron/exon structures within each subgroup. The VviBG gene family contained four tandem repeat gene clusters. There were intra-species synteny relationships between two pairs of VviBGs and inter-species synteny relationships between 20 pairs of VviBGs and AtBGs. The VviBG promoter contained many cis-acting elements related to stress and hormone responses. Tissue-specific analysis showed that VviBGs exhibited distinct spatial and temporal expression patterns. Transcriptome analysis indicated that many VviBGs were induced by wounds, UV, downy mildew, cold, salt and drought, especially eight VviBGs in subgroup A of the γ clade. RT-qPCR analysis showed that these eight VviBGs were induced under abiotic stress (except for VviBG41 under cold stress), and most of them were induced at higher expression levels by PEG6000 and NaCl than under cold treatment. The chromosome localization, synteny and phylogenetic analysis of the VviBG members were first conducted. The cis-acting elements, transcriptome data and RT-qPCR analysis showed that VviBG genes play a crucial role in grape growth and stress (hormone, biotic and abiotic) responses. Our study laid a foundation for understanding their functions in grape resistance to different stresses.

To reveal the mechanism by which exogenous dopamine (Da) regulates Shine Muscat grape (Vitis labrusca L. × Vitis vinifera L.) in response to low-temperature stress, annual Shine Muscat grape plants were used as material. Different concentrations of Da (0.2–1.0 mmol L⁻¹) were set to investigate its synergistic regulatory effects on grape photosynthetic protection, osmotic adjustment, ion homeostasis, antioxidant defense, and cold-responsive gene expression and to identify the optimal concentration and core pathways through correlation analysis. The results showed that low-temperature stress significantly inhibited plant growth, reduced photosynthetic efficiency, disrupted ion balance, induced oxidative damage, and downregulated the expression of cold-responsive genes. Da exhibited a “low-concentration promotion and high-concentration inhibition” effect, with the 0.4 mmol L⁻¹ treatment showing the best performance: growth indicators such as plant height and stem diameter increased by 22.4–52.2% compared with the low-temperature stress group; photosynthetic parameters and photosystem II (PSII) function were significantly improved; proline content increased by 40.3%; the Na⁺/K⁺ ratio decreased by 44.8%; activity of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD) increased by 31.7–49.5%; and the expression of genes in the C-repeat binding factor (CBF) family was upregulated. Correlation analysis confirmed that the activity of SOD and catalase (CAT) showed a highly significant positive correlation with growth indicators (r > 0.8, p < 0.01) and a highly significant negative correlation with malondialdehyde (MDA) content (r < −0.8, p < 0.01), indicating that antioxidant defense is the core pathway. In conclusion, exogenous Da enhances the cold tolerance of Shine Muscat grape through multi-pathway synergy, with 0.4 mmol L⁻¹ the optimal concentration, which can provide a theoretical basis for cold-resistant cultivation of grapes.

After normal pollination and fertilization of pseudoparthenocarpic seedless grapes, their embryos often stop developing due to certain developmental factors, resulting in embryo abortion. Hybrid breeding using seedless grapes as the maternal parent requires embryo rescue breeding technology. This technology plays a crucial role in seedless grape breeding. Although previous studies have extensively explored this technology, knowledge regarding its impact on embryo abortion and the effectiveness of rescue techniques remains limited. This study aimed to investigate the correlation between embryo rescue and hormonal changes in seedless grapes. Four Eurasian seedless grape cultivars, “Thompson Seedless,” “Flame Seedless,” “Heshi Seedless,” and “Ruby Seedless,” were selected for examination. We investigated endogenous hormone levels, including indole-3-acetic acid (IAA), gibberellic acid (GA₃), and abscisic acid (ABA), in both berries and in vitro ovules during the most suitable embryo rescue time for these cultivars. Based on the observed fluctuations in endogenous hormone levels and previous research findings, appropriate doses of exogenous hormones, such as IAA, GA₃, and ABA, were applied during seedless grape embryo rescue. The results indicated significant differences in endogenous hormone levels between berries with varying ovule counts of the same cultivar and ovules cultured in vitro, suggesting a hormonal influence on ovule abortion and embryo development in seedless grapes. Further research has identified effective ratios of exogenous hormones: 30 mg·L^–1 IAA + 30 mg·L^–1 ABA for berry ovule development, 1.0 mg·L^–1 IAA + 2.0 mg·L^–1 6-benzylaminopurine (6-BA) + 1.0 mg·L^–1 GA₃ + 1.0 mg·L^-1 ABA for in vitro ovule development, and 1.0 mg·L^–1 IAA + 2.0 mg·L^–1 6-BA + 1.0 mg·L^–1 GA₃ for embryo germination and seedling formation. In summary, hormonal changes significantly influence ovule and embryo development and are closely related to seedless grape embryo rescue breeding. This study deepened our understanding of the correlation between seedless grape embryo rescue and hormonal changes. It also resulted in the successful production of a batch of embryo rescue seedlings, further improving embryo rescue breeding technology and providing new germplasm materials for developing new seedless grape cultivars.

Vitis vinifera is a fruit tree species of great economic value worldwide. Nevertheless, chilling injury induced by cold stress restricts its yield and hinders the development of the grape industry. Based on previous findings of our research group that exogenous trehalose enhances abiotic stress tolerance in grape callus, this study adopted physiological, transcriptomic and metabolomic approaches to explore the potential regulatory relationships associated with exogenous trehalose. In this study, trehalose treatment alleviated chilling injury under 12 °C cold stress and increased the fresh weight of Vitis vinifera 'Thompson Seedless' callus. Meanwhile, trehalose application significantly elevated endogenous trehalose and soluble sugar content in grape callus, accompanied by increased activities of POD, SOD, and CAT, as well as reduced levels of MDA and O₂•⁻. KEGG enrichment analysis of transcriptomic data revealed that DEGs were mainly enriched in pathways related to biosynthesis of secondary metabolites, plant hormone signal transduction, starch and sucrose metabolism, and the MAPK signaling pathway in plants. Key DEGs included BAMS, STS, IAA, RLKs, and BGLU, while differentially expressed transcription factors were predominantly distributed in the AP2/ERF-ERF and MYB families. WGCNA identified the brown and turquoise modules as modules putatively correlated with physiological traits in grape callus, from which candidate genes potentially involved in trehalose-mediated cold response, including VQ22, RGLG2, PPR21, CML16, and SPL6, were screened. Combined transcriptomic and metabolomic analysis showed that DEGs and DAMs were jointly notably altered in the metabolic pathways of flavonoids, benzenes and their substituted derivatives, alkanolamines, terpenoids, and alkaloids. Moreover, all DAM-interacting genes identified were DEGs from the transcriptome. RT-qPCR analysis confirmed that the expression patterns of the selected cold-responsive genes were reliable and consistent with the transcriptomic results. Using integrated physiological, transcriptomic and metabolomic approaches, we identified candidate modules and genes related to cold tolerance in grape callus, as well as physiological responses and potential pathways underlying trehalose-mediated cold tolerance. We also characterized candidate genes involved in this regulatory process, providing a theoretical reference for exploring cold tolerance mechanisms in grape callus.

This study was envisaged to investigate the physiological reasons affecting the embryo development and abortion of seedless grapes on the basis of the previous embryo rescue breeding techniques of seedless grapes. Specifically, the relationship between the embryo rescue breeding of seedless grapes and the change of polyamine content was evaluated, in order to provide hybrid germplasm in the breeding of new seedless grape cultivars. Four ovules of 4 naturally pollinated Eurasian seedless grape cultivars, including ‘Thompson Seedless’ grape (hereinafter referred to as ‘Seedless White’ grape), ‘Flame Seedless’ grape, ‘Heshi Seedless’ grape and ‘Ruby Seedless’ grape were employed for the study. Changes in the endogenous polyamine content, exogenous polyamine content, and the suitable combination of exogenous polyamines in the seedless grape berries and isolated ovules were determined during the best embryo rescue period. Furthermore, the effect of different exogenous polyamine contents on the germination and seedling rate of different seedless grape embryos was analyzed. In the best embryo rescue period, the number of ovules had different effects on the content of polyamines. For seedless grape cultivars with 4 ovules, a high content of polyamines was found to be more beneficial in the embryonic development. The existence of embryos had different effects on the development of embryos. In the ovules with embryo, an increase in the content of polyamine was beneficial to the growth and development of the ovule. Different ratios of exogenous polyamines had varying effects on the embryonic development. Putrescine (Put) exhibited the greatest effect on the embryonic development. Further, correlation analysis showed that different combinations of exogenous polyamines had varying effects on the embryonic development. A maximal ovule development was observed in the combination of exogenous polyamines of putrescine2+spermidine2+spermine1. For maximal embryo germination and seeding formation, the optimal combination was putrescine2+spermidine2+spermine2. Irrespective to the number of ovules or the existence of embryos, the results indicated that a high content of endogenous polyamines promoted the growth and development of embryos. The embryo rescue efficiency of different exogenous polyamines was different, and the appropriate combination of exogenous polyamines was beneficial to the growth and development of ovules, with a high development rate of the ovule and seedling.

Grape (Vitis vinifera L.) is a globally paramount fruit crop, exerting a pivotal role in China’s agricultural production. However, the grape industry confronts core bottlenecks: centralized table grape listing resulting in recurrent oversupply, underdeveloped independent brand development, scarcity of internationally recognized cultivars, and suboptimal crossbreeding efficiency (e.g., concentrated 6 - 10-day flowering periods, complex flower ear structures, and stringent technical requirements for emasculation/pollination). To tackle these industry and breeding challenges, this study refined artificial hybridization pollination protocols and systematically analyzed pollen viability and hybridization affinity of nine male parents, using ‘Shine Muscat’ (Vitis labrusca × Vitis vinifera) grape as the female parent. Key findings revealed that pollen collection 1–2 days before messenger flower bloom optimizes viability, Ultra-low -80°C storage sustained pollen viability optimally. Precise early-stage anther removal and three-day pollination post stigma mucus secretion elevate the fruit set rate by 15%–20%. Hybrid combinations exhibited significant variations in fruit set rate (27.8%–62.3%), with ‘Moldova’ grape achieving the highest rate of 62.3%. A standardized process integrating parental selection, pollen management, emasculation-pollination, and data recording was established, elevating hybridization success rates by over 40%. This study delivers a scalable solution for grape cultivation.