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Drought stress impedes viticultural plant growth and development by modifying various metabolic pathways. However, the regulatory network response underlying drought stress is not yet clear. In this study, the leaves and roots of "Shine Muscat" ("SM," Vitis labruscana × Vitis vinifera) and "Thompson Seedless" ("TS," V. vinifera L. cv.) were subjected to drought stress to study the regulatory network used by drought stress. Morphophysiological results showed that the malondialdehyde content after 28 days of drought stress increased more significantly in "TS" than "SM." Furthermore, the multiomics analysis studies showed that a total of 3036–6714 differentially expressed genes and 379–385 differentially abundant metabolites were identified in "SM" and "TS" grapevine cultivars under drought stress. Furthermore, the retained intron was the major form of differential alternative splicing event under drought stress. The photosynthesis pathway, antioxidant system, plant hormone signal transduction, and osmotic adjustment were the primary response systems in the two grapevine cultivars under drought stress. We have identified GRIK1, RFS2, and LKR/SDH as the hub genes in the coexpression network of drought stress. In addition, the difference in the accumulation of pheophorbide‐a reveals different drought resistance mechanisms in the two grapevine cultivars. Our study explained the difference in drought response between cultivars and tissues and identified drought stress‐responsive genes, which provides reference data for further understanding the regulatory network of drought tolerance in grapevine. [ABSTRACT FROM AUTHOR]

Grapes are widely cultivated around the world and their quality has distinct regional characteristics. In this study, the qualitative characteristics of the 'Cabernet Sauvignon' grape variety in seven regions, from half-véraison to maturity, were analyzed comprehensively at physiological and transcriptional levels. The results indicated that the quality traits of 'Cabernet Sauvignon' grapes in different regions were significantly different with obvious regionality. Total phenols, anthocyanins, and titratable acids were the main factors of the regionality of berry quality, which were very sensitive to changes in the environment. It should be noted that the changes in titrating acids and total anthocyanin of berries vary greatly from half-véraison to maturity between regions. Moreover, the transcriptional analysis showed that the co-expressed genes between regions characterized the core transcriptome of berry development, while the unique genes of each region reflected the regionality of berries. The differentially expressed genes (DEGs) between half-véraison and maturity can be used to demonstrate that the environment of the regions could promote or inhibit gene expression. The functional enrichment suggested that these DEGs help to understand the interpretation of the plasticity of the quality composition of grapes according to the environment. Taken together, the information generated by this study could contribute to the development of viticultural practices aimed at making better use of native varieties for the development of wines with regional characteristics. [ABSTRACT FROM AUTHOR]

Grapes have excellent commercial characteristics and high nutritional value, but postharvest storage inevitably reduces their quality. Previously, we studied the regulatory mechanisms of methylation for grape ripening. To further investigate the effects of epigenetic modifications on postharvest quality of grape berries, Transcriptome deep sequencing (RNA-seq) and metabolome sequencing were performed on 5-Azacytidine (5azaC) or Trichostatin A (TSA) treated grape berries. TSA delayed the depletion of soluble sugar and organic acid content in postharvest grapes compared to controls, while 5azaC had the opposite effect. In addition, TSA and 5azaC affected the content and composition of volatile organic compounds (VOCs) in the berries, of which the decrease in linalool content may be directly responsible for the reduction of muscat flavor in the berries. RNA-Seq analysis showed that 626 and 2253 differentially expressed genes (DEGs) were generated by 5azaC and TSA treatments, respectively. GO and KEGG enrichment analyses revealed significant differences in the biological pathways involved in the two collections of DEGs. Metabolomic analyses further clarified the marker metabolites induced by TSA and 5azaC related to fruit quality. In addition, the results of HDAC activity and transcript levels of acetylation-related genes suggest that VvHDA15 may acetylation modification affects the key regulators of postharvest fruit quality. This study not only provides abundant data information, but also offers new insights into the regulation of fruit quality by epimodification. [Display omitted] • TSA and 5azaC affected sugar, organic acid and aroma in postharvest grapes. • TSA and 5azaC altered gene expression and metabolite levels. • VvHDA15 is a key candidate gene for acetylation regulation of postharvest fruit quality. [ABSTRACT FROM AUTHOR]

Grape (Vitis vinifera L.) is an important fruit for which light quality plays a significant role in plant growth and development. However, the regulatory mechanisms between light quality and plant growth at the physiological and molecular levels are poorly understood. Therefore, in the present study, we performed multivariate sequencing analysis to investigate the effects of four light qualities: blue (B), red (R), green (G), and white (W, used as a control group) to investigate grapevine morphology at the molecular level, which revealed the possible networking pathway controlling grapevine growth. Our results showed that morphological and physiological parameters, such as plant height, stem diameter, leaf area, and the contents of total chlorophyll, chlorophyll a and b, and carotenoid, were significantly improved under blue and red light compared to those under white light. Photosynthetic measurements showed that the total conductance to water vapor, total conductance to water CO 2 , maximum quantum yield of photosystem (PS)II, apparent electron transfer chain, and net photosynthetic rate were elevated by blue and red light compared to white light. However, there were notable reductions in the intercellular CO 2 concentration, transpiration rate, and non-photochemical quenching coefficient under blue light, which showed an irreversible trend compared to other light qualities. The contents of minerals, such as nitrogen, phosphorous, potassium, magnesium, iron, and zinc, were also improved by blue and red light compared to white light. Multivariate sequencing analysis revealed a total of 1065 metabolites, of which 747 were positive and 318 were negative. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that many differentially expressed genes (DEGs) were associated with the biosynthesis of secondary metabolites, including flavones, flavonols, and alkaloids, and metabolic and phenylpropanoid pathways. Further, numerous transcription factors, including MYB (37 DEGs), bHLH (32 DEGs), NAC (31 DEGs), and WRKY (29 DEGs), were reported. Photosynthesis-related genes (PsaD, PsaO, PsbB, PetC, PetE, PetF, PetH, PetJ, and Lhca) played pivotal roles in the photosynthetic pathways. In addition, using weighed gene correlation network analysis, 7 module relationships (MEblack, MEgreenyellow, MEred, MEturquoise, MEgreen, MEyellow, and MEmagneta), 4 metabolites, 14 structural genes, and 36 transcription factor-related genes were found. Conclusively, the present research provides new insights for viticulture in response to light quality and offers new strategies for agriculture. [Display omitted] • Blue light treatment increased photosynthesis and material content of grape seedlings. • After 30 days of continuous light quality treatment, photosynthesis was reduced compared to 15 days. • Blue light, red light and green light affect sugar metabolism and amino acid metabolism to some extent. [ABSTRACT FROM AUTHOR]

• Low-temperature promotes the accumulation of anthocyanins in grape leaves by up-regulating the expression of structural genes that induce anthocyanin synthesis, related transcription factors and LRR-type receptor-like protein kinases. • Under the same low-temperature environment, the more anthocyanin accumulated in the leaves, the less damage they suffered. • The synthesis and accumulation of anthocyanins promoted the adaptation and resistance of grape leaves to low-temperature environmental conditions. Anthocyanins can be induced by environmental factors such as low- temperature, and play an important role in adapting to abiotic stress. In this study, the leaves of 'Cabernet Gernischt' grapes with different colors under natural low-temperature in autumn were collected and grouped into Green (Gre), Light-red (L-Red), Red (Red), and Dark-red (D-Red). Results showed that the total anthocyanin content and anthocyanin components were increased in turn from Gre to D-red. Under the same low-temperature, Gre was substantially damaged, L-Red was mildly damaged, Red and D-Red had no visible damage. RNA-seq data showed that a total of 3666 DEGs were screened out of all 28,306 genes detected, of which 1936 DEGs were upregulated and 1730 DEGs were downregulated in D-Red vs Gre. Transcriptomics and metabolomics showed that DEGs were significantly enriched in GO terms, such as in defense response, defense response to oomycetes, and response to reactive oxygen species, hydrogen peroxide, heat, salt stress, and biotic stimulus pathways. The KEGG analysis showed that DEGs were mainly enriched in secondary metabolism, carbohydrate metabolism, energy metabolism, and lipid metabolism. Anthocyanin synthesis genes may be regulated by transcription factors such as ERF, MYB, NAC, bHLH and various LRR-type receptor-like protein kinase (LRR-RLK) family genes. In conclusion, the accumulation of anthocyanins significantly increased from green to red in grape leaves during autumn low-temperature, improving the cold resistance of grape leaves. [ABSTRACT FROM AUTHOR]

• VvSnRK2.2 and VvSnRK2.7 promoted the berry ripening process on a molecular and physiological level. • VvSnRK2.3 and VvSnRK2.6 induced high resistance of fruits to Botrytis cinerea. • VvSnRK2 family genes were studied systematically. Even though abscisic acid (ABA) plays a significant role in fruit growth and responses to a variety of environmental stimuli, the signaling mechanisms that underpin these activities are unknown. role. In present study, we identified seven sucrose non-fermenting-1-related protein kinases 2 (SnRK2s) from the grape (Vitis vinifera L.) genome, which may localized in the nucleus, membrane, and cytoplasm. The overexpression (OE) of VvSnRK2 s showed that VvSnRK2.2 and VvSnRK2.7 promoted the ripening process in strawberries on molecular and physiological levels (fruit weight, berry firmness, cell wall composition, total soluble sugar, titratable acid, pigments, phenolic compounds), furthermore, VvSnRK2.3 and VvSnRK2.6 induced strong resistance in strawberry fruits to B. cinerea. Only VvSnRK2.2 and VvSnRK2.7 were found to interact with VvMYB24, a positive regulator of grape berry ripening. Additionally, VvSnRK2s interact with VvABF1 (an ABA-responsive factor) and VvABI1 (ABA insensitive 1) to mediate the ABA signalling pathway. VvSnRK2 s respond to different hormonal treatments and abiotic stresses to improve plant stress resistance. Collectively, our results demonstrated that VvSnRK2.2 and VvSnRK2.7 are positive regulators grape berry development and ripening, while, VvSnRK2.3 and VvSnRK2.6 mediate grape resistance against B. cinerea. [ABSTRACT FROM AUTHOR]

• VvERF17 was an ethylene response factor, the expression of which was strongly correlates with chlorophyll degradation. • Transgenic expression of VvERF17 modulated chlorophyll content and related genes' expression. • VvERF17 could activate the expression of major chlorophyll catabolic genes by directly binding to the ERF binding sites in their promoters. • VvERF17 mediates chlorophyll degradation by transcriptional activation of NOL , PPH , PAO , and RCCR. Chlorophylls in the skin contribute to grape (Vitis vinifera) berry color and quality. Degradation of chlorophyll occurs during berry development in grape, but less is known about the molecular mechanisms of this process. Here, we characterized an ethylene response factor, VvERF17, as a putative regulator of chlorophyll degradation in grape berry. VvERF17 expression was strongly correlates with development-induced and ETH-triggered chlorophyll degradation. Transient overexpression of VvERF17 in tobacco leaves, tomato fruits, and grape leaves led to color break and chlorophyll degradation, which were resulted from the upregulated expression of chlorophyll catabolic genes (CCGs), including Chlorophyll-b-reductase (NOL), pheophytinase (PPH), pheophorbide a oxygenase (PAO), and red Chlorophyll catabolite reductase (RCCR). Inversely, silencing of VvERF17 in grape leaves partially suppressed the expression of CCGs' expression. Major CCGs' expression was closely related to chlorophyll degradation and VvERF17 expression. It was further demonstrated that VvERF17 could activate the expression of major CCGs by directly binding to the ERF binding sites in their promoters. We conclude that VvERF17 mediates chlorophyll degradation by transcriptional activation of NOL , PPH , PAO , and RCCR. These findings elucidate the regulation mechanisms of chlorophyll degradation in grape and enrich our understanding of grape berry color formation. [ABSTRACT FROM AUTHOR]