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Norisoprenoids are important chemical compounds to grape and wine aroma, and their content in the grape berries can be greatly affected by varietal, terroir, and environmental factors. In this study, we investigate how major factors, such as genotype and climate conditions, influence the physicochemical properties of grape juice, volatile C13-norisoprenoid compounds, and gene expression profiles of three Vitis vinifera grape varieties: Muscat blanc à Petit grain, Muscat à petits grains rouges, and Gewürztraminer during the production period in 2010 and 2011. The total soluble solids (TSS) of both Muscat varieties were significantly higher in 2011 compared to 2010, reflecting interannual climatic variations, while Gewürztraminer showed no significant differences. At full maturity, total acid of all three cultivars was consistent between the years, indicating genetic determination. Thirteen norisoprenoids were identified, with Muscat varieties showing consistently higher levels than Gewürztraminer, irrespective of the production year. Varietal differences were significant for 13 out of 14 volatile compounds, and vintage effects were notable for 11 compounds, including key aroma contributors β-damascenone and β-ionone. OPLS-DA analysis highlighted distinct volatile profiles for each variety and vintage, influenced by climatic factors such as precipitation and sunlight hours. Gene expression analysis revealed strong correlations between VvCCD1, VvCCD4a, and VvCCD4b genes and C13-norisoprenoid accumulation, with these genes also implicated in the ABA biosynthesis pathway. Single nucleotide polymorphisms (SNPs) in VvCCD1, VvCCD4a, and VvCCD4b were linked to variations in norisoprenoid content among the cultivars. Altogether, these findings revealed the interaction of genetic and environmental factors in shaping the physicochemical properties for the grape, volatile profiles, and gene expression patterns of grape berries, with significant implications for viticulture and the winemaking process. [ABSTRACT FROM AUTHOR]

An undesirable sensory attribute ("floral taint") has recently been detected in red wines from some winegrowing jurisdictions in North America (e.g., Ontario, British Columbia, Washington), caused by the introduction of frost-killed leaves and petioles [materials-other-than-grapes (MOG)] during mechanical harvest and winemaking. It was hypothesized that terpenes, norisoprenoids, and higher alcohols would be the main responsible compounds. The objectives were to investigate the causative volatile compounds for floral taint and explore threshold concentrations for this problem. Commercial wines displaying varying intensities of floral taint were subjected to GC-MS and sensory analysis. Several odor-active compounds were higher in floral-tainted wines, including terpenes (geraniol, citronellol, cis- and trans-rose oxide), norisoprenoids (β-damascenone, β-ionone), five ethyl esters, and three alcohols. Thereafter, fermentations of Cabernet Franc (CF) and Cabernet Sauvignon (CS) (2016, 2017) were conducted. MOG treatments were (w/w): 0, 0.5%, 1%, 2%, and 5% petioles, and 0, 0.25%, 0.5%, 1%, and 2% leaf blades. Terpenes (linalool, geraniol, nerol, nerolidol, citronellol, citral, cis- and trans-rose oxides, eugenol, myrcene), norisoprenoids (α- and β-ionone), and others (e.g., hexanol, octanol, methyl and ethyl salicylate) increased linearly/quadratically with increasing MOG levels in both cultivars. Principal components analysis separated MOG treatments from the controls, with 5% petioles and 2% leaves as extremes. Increasing MOG levels in CF wines increased floral aroma intensity, primarily associated with terpenes, higher alcohols, and salicylates. Increased leaf levels in CF were associated with higher vegetal and earthy attributes. Increased petioles in CS were not correlated with floral aromas, but increased leaves increased floral, vegetal, and herbaceous attributes. Overall, petioles contributed more to floral taint than leaves through increased terpenes and salicylates (floral notes), while leaves predominantly contributed norisoprenoids and C6 alcohols (green notes). [ABSTRACT FROM AUTHOR]

The wide ampelographic treasure of Italian wine grape varieties is driving research towards suitable approaches for the varietal authenticity control of wine. In this paper, Aglianico, Negroamaro, Primitivo and Uva di Troia red wines, which were produced experimentally by single-grape winemaking from non-aromatic grapes native to southern Italy, were analyzed with respect to berry markers, namely anthocyanins, hydroxycinnamic acids (HPLC-DAD), shikimic acid (HPLC-UV) and glycosidic aroma precursors (GC-MS). The study confirms that, just as for the berries, useful varietal authenticity markers for red wine, even after aging, turn out to be hydroxycinnamic acids, relative amounts of acylated forms of anthocyanins, and shikimic acid, together with some grape glycosidic precursors from terpenes and C13− norisoprenoids. Principal Component Analysis was used as a valuable tool to highlight the results. [ABSTRACT FROM AUTHOR]

Chardonnay is a non-floral grape with economic value and nutritional properties that is widely grown in northwestern China. However, limited research has been conducted on exogenous spraying to regulate volatile compound metabolism (especially isoprene metabolism) in Chardonnay grapes. Benzothiadiazole (BTH) can induce disease resistance and augment the contents of phenolics and volatile compounds in grapes. This study aimed to evaluate the influence of BTH on the accumulation of isoprene aroma, carotenoid levels and the activity profiles of key enzymes. Chardonnay grapevines were treated with 0.37 mM BTH at veraison to investigate the impact on physicochemical parameters, carotenoids, metabolic enzyme activities, and free and bound isoprenoids in developing Chardonnay grapes. The results showed that reducing sugars, and total soluble solids of BTH-treated grapes increased, while the content of titratable acidity, β-carotene, zeaxanthin, β-cryptoxanthin, chlorophyll, and total carotenoids in treated ripe grapes decreased relative to control berries. BTH-treated ripe grapes exhibited elevated levels of bound norisoprenoids and three key enzemy activities (carotenoid cleavage dioxygenase, phytoene synthase, lycopene β-cyclase), with a slight decrease in free norisoprenoids. Free and bound terpenoids profiles were also significantly enhanced by BTH treatment at veraison. Our findings offer novel perspectives into the modulation of isoprene biosynthesis in grape berries when exposed to BTH. [ABSTRACT FROM AUTHOR]

Norisoprenoids are important chemical compounds to grape and wine aroma, and their content in the grape berries can be greatly affected by varietal, terroir, and environmental factors. In this study, we investigate how major factors, such as genotype and climate conditions, influence the physicochemical properties of grape juice, volatile C13-norisoprenoid compounds, and gene expression profiles of three Vitis vinifera grape varieties: Muscat blanc à Petit grain, Muscat à petits grains rouges, and Gewürztraminer during the production period in 2010 and 2011. The total soluble solids (TSS) of both Muscat varieties were significantly higher in 2011 compared to 2010, reflecting interannual climatic variations, while Gewürztraminer showed no significant differences. At full maturity, total acid of all three cultivars was consistent between the years, indicating genetic determination. Thirteen norisoprenoids were identified, with Muscat varieties showing consistently higher levels than Gewürztraminer, irrespective of the production year. Varietal differences were significant for 13 out of 14 volatile compounds, and vintage effects were notable for 11 compounds, including key aroma contributors β-damascenone and β-ionone. OPLS-DA analysis highlighted distinct volatile profiles for each variety and vintage, influenced by climatic factors such as precipitation and sunlight hours. Gene expression analysis revealed strong correlations between VvCCD1, VvCCD4a, and VvCCD4b genes and C13-norisoprenoid accumulation, with these genes also implicated in the ABA biosynthesis pathway. Single nucleotide polymorphisms (SNPs) in VvCCD1, VvCCD4a, and VvCCD4b were linked to variations in norisoprenoid content among the cultivars. Altogether, these findings revealed the interaction of genetic and environmental factors in shaping the physicochemical properties for the grape, volatile profiles, and gene expression patterns of grape berries, with significant implications for viticulture and the winemaking process.

An undesirable sensory attribute (“floral taint”) has recently been detected in red wines from some winegrowing jurisdictions in North America (e.g., Ontario, British Columbia, Washington), caused by the introduction of frost-killed leaves and petioles [materials-other-than-grapes (MOG)] during mechanical harvest and winemaking. It was hypothesized that terpenes, norisoprenoids, and higher alcohols would be the main responsible compounds. The objectives were to investigate the causative volatile compounds for floral taint and explore threshold concentrations for this problem. Commercial wines displaying varying intensities of floral taint were subjected to GC-MS and sensory analysis. Several odor-active compounds were higher in floral-tainted wines, including terpenes (geraniol, citronellol, cis- and trans-rose oxide), norisoprenoids (β-damascenone, β-ionone), five ethyl esters, and three alcohols. Thereafter, fermentations of Cabernet Franc (CF) and Cabernet Sauvignon (CS) (2016, 2017) were conducted. MOG treatments were (w/w): 0, 0.5%, 1%, 2%, and 5% petioles, and 0, 0.25%, 0.5%, 1%, and 2% leaf blades. Terpenes (linalool, geraniol, nerol, nerolidol, citronellol, citral, cis- and trans-rose oxides, eugenol, myrcene), norisoprenoids (α- and β-ionone), and others (e.g., hexanol, octanol, methyl and ethyl salicylate) increased linearly/quadratically with increasing MOG levels in both cultivars. Principal components analysis separated MOG treatments from the controls, with 5% petioles and 2% leaves as extremes. Increasing MOG levels in CF wines increased floral aroma intensity, primarily associated with terpenes, higher alcohols, and salicylates. Increased leaf levels in CF were associated with higher vegetal and earthy attributes. Increased petioles in CS were not correlated with floral aromas, but increased leaves increased floral, vegetal, and herbaceous attributes. Overall, petioles contributed more to floral taint than leaves through increased terpenes and salicylates (floral notes), while leaves predominantly contributed norisoprenoids and C6 alcohols (green notes).

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Abstract Background The biochemical makeup of grape berries at harvest is essential for wine quality and depends on a fine transcriptional regulation occurring during berry development. In this study, we conducted a comprehensive survey of transcriptomic and metabolomic changes occurring in different berry tissues and developmental stages of the ancient grapes Aglianico and Falanghina to establish the patterns of the secondary metabolites contributing to their wine aroma and investigate the underlying transcriptional regulation. Results Over two hundred genes related to aroma were found, of which 107 were differentially expressed in Aglianico and 99 in Falanghina. Similarly, 68 volatiles and 34 precursors were profiled in the same samples. Our results showed a large extent of transcriptomic and metabolomic changes at the level of isoprenoids (terpenes, norisoprenoids), green leaf volatiles (GLVs), and amino acid pathways, although the terpenoid metabolism was the most distinctive for Aglianico, and GLVs for Falanghina. Co-expression analysis that integrated metabolome and transcriptome data pinpointed 25 hub genes as points of biological interest in defining the metabolic patterns observed. Among them, three hub genes encoding for terpenes synthases (VvTPS26, VvTPS54, VvTPS68) in Aglianico and one for a GDP-L-galactose phosphorylase (VvGFP) in Falanghina were selected as potential active player underlying the aroma typicity of the two grapes. Conclusion Our data improve the understanding of the regulation of aroma-related biosynthetic pathways of Aglianico and Falanghina and provide valuable metabolomic and transcriptomic resources for future studies in these varieties.

BACKGROUND: The present study aimed to assess the chemical and sensory variability existing across sparkling white wines of a single appellation in relation to production technique and aging, identifying the existence of specific aroma chemical and sensory (odor) signatures. For this purpose, we selected Durello, an emerging sparkling white wine from the Veneto region produced using either Charmat or Classico methods. RESULTS: Comparison of Durello varietal volatiles profile with other Italian sparkling and still wines highlighted specific features of Durello, such as high content of 1,4‐cineole and non‐megastigmane norisoprenoids. The production technique (Charmat or Champenoise) impacted both the volatile chemical profile, influencing the content of esters, fatty acids, cyclic terpenoids, C6 alcohols, β‐damascenone and methanethiol. With regard to wine age and vintage, an influence on esters, p‐menthane‐1,8‐diol, cineoles and methyl salicylate was observed. CONCLUSION: Sensory evaluation by means of a sorting task approach indicated the existence of two main types of odor profile, one clearly associated with Classico method. The main drivers of such aroma diversity were esters, 1,4‐cineole and methanethiol. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Qingke (highland barley) Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau. Since the pine board is used as the bottom of the fermentation pit, we deduced that the terpenoids and norisoprenoids in pine board might be introduced into Qingke Baijiu. Thus, the terpenoids and norisoprenoids in Qingke Baijiu were investigated by headspace solid phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS). The results showed that γ-terpinene (0.70–530.72 μg/L), α-phellandrene (0.34–256.66 μg/L), longicyclene (0–38.55 μg/L), α-pinene (1.21–35.54 μg/L) and limonene (0.93–23.69 μg/L) were the top 5 terpenoids/norisoprenoids in Qingke Baijiu. Pulegone was detected and reported for the first time in Baijiu, and the concentrations in Qingke Baijiu were 0.78 μg/L (fresh) and 3.90 μg/L (7 years old). According to the principal component analysis (PCA) plot, young, aged, and retail Qingke Baijiu could be differentiated clearly. Fold change (FC) and t-tests analysis indicated that β-pinene, γ-terpinene, and α-selinene were the most different terpenoids/norisoprenoids between young and aged Qingke Baijiu, and longifolene was the most different terpenoids/norisoprenoids between base and retail Qingke Baijiu. The terpenoids and norisoprenoids, such as (E)-β-ionone, isoborneol and β-cyclocitral, could be potential markers indicating the ageing process of Qingke Baijiu.

Mango juice (MJ) was co-inoculated with Lactobacillus plantarum + Rhodotorula glutinis or Metschnikowia pulcherrima (LP + RG or LP + MP, respectively) and Lactobacillus casei + Rhodotorula glutinis or Metschnikowia pulcherrima (LC + RG or LC + MP, respectively) to evaluate their effect on the physicochemical characteristics, antioxidant capacity, and aroma compounds of MJ after 72 h of fermentation at 28 °C. Results indicated that among the fermented MJ, that which was fermented with LC + RG yielded the highest content of total acid (15.05 g/L). The pH values of MJ fermented with LC + MP, LC + RG, LP + RG, and LP + MP were 3.36, 3.33, 3.26, and 3.19, respectively, and were lower than that of CK (4.79). The juice fermented with LP + MP culture had the lowest sugar content (73.52 g/L), and those fermented with LP + RG and LP + MP had higher total phenol contents and stronger DPPH radical scavenging activity, ABTS radical scavenging activity, iron-reducing antioxidant capacity, and copper reducing antioxidant capacity than the others. Carotenoids in MJ had varying degrees of degradation after mixed fermentation by using all four combinations. Volatile compounds revealed that the co-fermentation of LP + RG produced increased norisoprenoid aroma compounds. The mixed co-inoculation method is a strategy to contemplate for MJ fermentation, but the modalities of inoculation need further investigation. Success depends on the suitable combination of non-Saccharomyces and lactic acid bacteria and consideration of strain variation. [ABSTRACT FROM AUTHOR]

Background: The biochemical makeup of grape berries at harvest is essential for wine quality and depends on a fine transcriptional regulation occurring during berry development. In this study, we conducted a comprehensive survey of transcriptomic and metabolomic changes occurring in different berry tissues and developmental stages of the ancient grapes Aglianico and Falanghina to establish the patterns of the secondary metabolites contributing to their wine aroma and investigate the underlying transcriptional regulation. Results: Over two hundred genes related to aroma were found, of which 107 were differentially expressed in Aglianico and 99 in Falanghina. Similarly, 68 volatiles and 34 precursors were profiled in the same samples. Our results showed a large extent of transcriptomic and metabolomic changes at the level of isoprenoids (terpenes, norisoprenoids), green leaf volatiles (GLVs), and amino acid pathways, although the terpenoid metabolism was the most distinctive for Aglianico, and GLVs for Falanghina. Co-expression analysis that integrated metabolome and transcriptome data pinpointed 25 hub genes as points of biological interest in defining the metabolic patterns observed. Among them, three hub genes encoding for terpenes synthases (VvTPS26, VvTPS54, VvTPS68) in Aglianico and one for a GDP-L-galactose phosphorylase (VvGFP) in Falanghina were selected as potential active player underlying the aroma typicity of the two grapes. Conclusion: Our data improve the understanding of the regulation of aroma-related biosynthetic pathways of Aglianico and Falanghina and provide valuable metabolomic and transcriptomic resources for future studies in these varieties. [ABSTRACT FROM AUTHOR]

Obtaining new grapevine varieties with unique aromas has been a long-standing goal of breeders. Norisoprenoids are of particular interest to wine producers and researchers, as these compounds are responsible for the important varietal aromas in wine, characterized by a complex floral and fruity smell, and are likely present in all grape varieties. However, the single-nucleotide polymorphism (SNP) loci and candidate genes genetically controlling the norisoprenoid content in grape berry remain unknown. To this end, in this study, we investigated 13 norisoprenoid traits across two years in an F1 population consisting of 149 individuals from a hybrid of Vitis vinifera L. cv. Muscat Alexandria and V. vinifera L. cv. Christmas Rose. Based on 568,953 SNP markers, genome-wide association analysis revealed that 27 candidate SNP loci belonging to 18 genes were significantly associated with the concentrations of norisoprenoid components in grape berry. Among them, 13 SNPs were confirmed in a grapevine germplasm population comprising 97 varieties, including two non-synonymous mutations SNPs within the VvDXS1 and VvGGPPS genes, respectively in the isoprenoid metabolic pathway. Genotype analysis showed that the grapevine individuals with the heterozygous genotype C/T at chr5:2987350 of VvGGPPS accumulated higher average levels of 6- methyl-5-hepten-2-one and b-cyclocitral than those with the homozygous genotype C/C. Furthermore, VvGGPPS was highly expressed in individuals with high norisoprenoids concentrations. Transient overexpression of VvGGPPS in the leaves of Vitis quinquangularis and tobacco resulted in an increase in norisoprenoid concentrations. These findings indicate the importance of VvGGPPS in the genetic control of norisoprenoids in grape berries, serving as a potential molecular breeding target for aroma. [ABSTRACT FROM AUTHOR]

Kirkwood Navel and Ruby Valencia red-fleshed sweet oranges accumulate high concentrations of the carotenes phytoene, phytofluene and lycopene in the pulp. In order to gain insight into the parameters that influence fruit quality in these varieties, a comparative analysis of volatile organic compounds (VOCs) in the pulp of Kirkwood Navel and Ruby Valencia red-fleshed sweet oranges and their standard blond counterparts, Navel and Valencia, was performed during fruit development and ripening. A total of 95 VOCs were identified by HS-SPME/GC–MS during the ripening process. The observed differences in VOCs between red-fleshed and blond oranges were more closely related to the fruit ripening stage than to the genotype. However, two distinctive common features were identified in both red-fleshed oranges compared to their respective standard varieties. These were lower levels of sesquiterpenes and higher levels of the norisoprenoids 6-methyl-5-hepten-2-one and geranylacetone. These findings indicate that altered carotenoid metabolism in red-fleshed oranges not only affects flesh pigmentation but also leads to changes in specific VOCs that may influence flavor perception. • Red-fleshed oranges accumulate large amounts of carotenes in the pulp. • Ninety-five volatiles were identified in the pulp of red-fleshed and standard oranges. • Red and standard orange volatiles were affected more by fruit ripening stage than genotype. • Red oranges showed higher levels of specific norisoprenoids and reduced of sesquiterpenes. • Alteration of carotenes in red oranges may affect specific volatiles and fruit aroma. [ABSTRACT FROM AUTHOR]

Backgroundβ-Ionone is a fragrant terpenoid that generates a pleasant floral scent and is used in diverse applications as a cosmetic and flavoring ingredient. A growing consumer desire for natural products has increased the market demand for natural β-ionone. To date, chemical extraction from plants remains the main approach for commercial natural β-ionone production. Unfortunately, changing climate and geopolitical issues can cause instability in the β-ionone supply chain. Microbial fermentation using generally recognized as safe (GRAS) yeast offers an alternative method for producing natural β-ionone. Yarrowia lipolytica is an attractive host due to its oleaginous nature, established genetic tools, and large intercellular pool size of acetyl-CoA (the terpenoid backbone precursor).ResultsA push-pull strategy via genome engineering was applied to a Y. lipolytica PO1f derived strain. Heterologous and native genes in the mevalonate pathway were overexpressed to push production to the terpenoid backbone geranylgeranyl pyrophosphate, while the carB and biofunction carRP genes from Mucor circinelloides were introduced to pull flux towards β-carotene (i.e., ionone precursor). Medium tests combined with machine learning based data analysis and 13C metabolite labeling investigated influential nutrients for the β-carotene strain that achieved > 2.5 g/L β-carotene in a rich medium. Further introduction of the carotenoid cleavage dioxygenase 1 (CCD1) from Osmanthus fragrans resulted in the β-ionone production. Utilization of in situ dodecane trapping avoided ionone loss from vaporization (with recovery efficiencies of ~ 76%) during fermentation operations, which resulted in titers of 68 mg/L β-ionone in shaking flasks and 380 mg/L in a 2 L fermenter. Both β-carotene medium tests and β-ionone fermentation outcomes indicated the last enzymatic step CCD1 (rather than acetyl-CoA supply) as the key bottleneck.ConclusionsWe engineered a GRAS Y. lipolytica platform for sustainable and economical production of the natural aroma β-ionone. Although β-carotene could be produced at high titers by Y. lipolytica, the synthesis of β-ionone was relatively poor, possibly due to low CCD1 activity and non-specific CCD1 cleavage of β-carotene. In addition, both β-carotene and β-ionone strains showed decreased performances after successive sub-cultures. For industrial application, β-ionone fermentation efforts should focus on both CCD enzyme engineering and strain stability improvement.

The deterioration of aroma quality in tea beverages during the shelf life is a significant issue. In this study, sensomics techniques were employed to identify the characteristic factor contributing to aroma degradation in green tea infusion. Samples A (no/faint retort odor) and B (high intensity retort odor) were selected based on their retort-like odor intensity after heat treatment simulating shelf-life conditions. The key odorants were identified through a combination of chemometrics analysis, comparative aromatic extract dilution analysis (cAEDA), detection frequency analysis (DFA), and odor-specific magnitude estimation (OSME). Subsequently, eight odorants, including linalool (892.451 μg/L), (E)-β-damascenone (5.105 μg/L), phenylacetaldehyde (27.720 μg/L), nonanal (2201.439 μg/L), α-terpineol (7.166 μg/L), geraniol (0.499 μg/L), theaspirane (0.044 μg/L), and 2-hydroxy-5-methylacetophenone (2.973 μg/L), were identified as the key substances contributing to the retort-like odor in sample B. Aroma recombination and omission test further demonstrated that elevated concentrations of nonanal, geraniol, phenylacetaldehyde, and theaspirane might be the primary reasons for the retort odor observed in samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Although grapes accumulate diverse groups of volatile compounds, their genetic regulation in different cultivars remains unelucidated. Therefore, this study investigated the volatile composition in the berries of an interspecific hybrid population from a Vitis labruscana 'Campbell Early' (CE) × Vitis vinifera 'Muscat of Alexandria' (MA) cross to understand the relationship among volatile compounds and their genetic regulation. Then, a quantitative trait locus (QTL) analysis of its volatile compounds was conducted. Results: While MA contained higher concentrations of monoterpenes and norisoprenoids, CE contained higher concentrations of C6 compounds, lactones and shikimic acid derivatives, including volatiles characteristic to American hybrids, i.e., methyl anthranilate, o-aminoacetophenone and mesifurane. Furthermore, a cluster analysis of volatile profiles in the hybrid population discovered ten coordinately modulated free and bound volatile clusters. QTL analysis identified a major QTL on linkage group (LG) 5 in the MA map for 14 monoterpene concentrations, consistent with a previously reported locus. Additionally, several QTLs detected in the CE map affected the concentrations of specific monoterpenes, such as linalool, citronellol and 1,8-cineol, modifying the monoterpene composition in the berries. As for the concentrations of five norisoprenoids, a major common QTL on LG2 was discovered first in this study. Several QTLs with minor effects were also discovered in various volatile groups, such as lactones, alcohols and shikimic acid derivatives. Conclusions: An overview of the profiles of aroma compounds and their underlying QTLs in a population of interspecific hybrid grapes in which muscat flavor compounds and many other aroma compounds were mixed variously were elucidated. Coordinate modulation of the volatile clusters in the hybrid population suggested an independent mechanism for controlling the volatiles of each group. Accordingly, specific QTLs with significant effects were observed for terpenoids, norisoprenoids and some volatiles highly contained in CE berries. [ABSTRACT FROM AUTHOR]

This work aimed to investigate the occurrence of different monoterpenoids and norisoprenoids in 10 monovarietal Italian red wines (Aglianico, Cannonau, Corvina, Montepulciano, Nebbiolo, Nerello, Primitivo, Raboso, Sangiovese and Teroldego) from 12 regions across Italy. The wines were produced in their terroirs following the oenological practices and legislation of the respective appellation. Data showed that different wine varietals were characterised by peculiar profiles of monoterpenoids and norisoprenoids. Montepulciano and Cannonau wines showed highest levels of nerol, terpinolene, α-terpineol, limonene and of the norisoprenoids β-damascenone, α-ionone, TPB, TDN and vitispirane. Aglianico, Corvina, Nebbiolo and Primitivo were characterised by relatively high levels of linear monoterpene alcohols such as linalool and geraniol. Sangiovese samples from Tuscany could be differentiated from those of Romagna, with the former characterised by a higher content of α-terpinene and the latter of γ-terpinene. The monoterpene 1,4-cineole was present in Montepulciano, Raboso and Sangiovese at potentially relevant olfactory levels, its occurrence associated with higher content of terpinen-1-ol acting as a potential precursor under wine acid conditions.

Mango juice (MJ) was co-inoculated with Lactobacillus plantarum + Rhodotorula glutinis or Metschnikowia pulcherrima (LP + RG or LP + MP, respectively) and Lactobacillus casei + Rhodotorula glutinis or Metschnikowia pulcherrima (LC + RG or LC + MP, respectively) to evaluate their effect on the physicochemical characteristics, antioxidant capacity, and aroma compounds of MJ after 72 h of fermentation at 28 °C. Results indicated that among the fermented MJ, that which was fermented with LC + RG yielded the highest content of total acid (15.05 g/L). The pH values of MJ fermented with LC + MP, LC + RG, LP + RG, and LP + MP were 3.36, 3.33, 3.26, and 3.19, respectively, and were lower than that of CK (4.79). The juice fermented with LP + MP culture had the lowest sugar content (73.52 g/L), and those fermented with LP + RG and LP + MP had higher total phenol contents and stronger DPPH radical scavenging activity, ABTS radical scavenging activity, iron-reducing antioxidant capacity, and copper reducing antioxidant capacity than the others. Carotenoids in MJ had varying degrees of degradation after mixed fermentation by using all four combinations. Volatile compounds revealed that the co-fermentation of LP + RG produced increased norisoprenoid aroma compounds. The mixed co-inoculation method is a strategy to contemplate for MJ fermentation, but the modalities of inoculation need further investigation. Success depends on the suitable combination of non-Saccharomyces and lactic acid bacteria and consideration of strain variation.

[Display omitted] • Bacillus subtilis -HNU-B3 increased the antioxidant activity of fermented mango-juice. • Norioprenoids and acetoin affected the favor of fermented mango juice. • Bacillus subtilis -HNU-B3 is a promising alternative for mango-juice fermentation. Mango juice (MJ) has high nutritional value and decent flavor. However, its aroma could be easily changed by heat treatment during processing, which affects its acceptability and quality. In this study, Bacillus subtilis -HNU-B3 that could transfer carotenoid, was obtained from orchard soil to improve the aroma of fermented mango juice (FMJ). Compared with MJ, the organic acid content of FMJ by B. subtilis -HNU-B3 was significantly changed, and the contents of succinic acid and malic acid were increased to 3.68 mg/mL and 2.04 mg/mL, respectively. Moreover, volatile compounds identified by headspace solid-phase micro-extraction gas-phase mass spectrometry in FMJ were norisoprenoid and acetoin, accounting for 51.52 % of the total volatile substances. In addition, B. subtilis -HNU-B3 fermentation significantly increased the antioxidant capacity and total phenol contents of MJ, and the activity of carotenoid cleavage dioxygenase was 188 U/L. In conclusion, the aroma of FMJ could be improved by B. subtilis -HNU-B3 through increasing the content of norisoprenoid and acetoin. Our results provide theatrical support for Bacillus subtilis to improve the aroma quality of FMJ. [ABSTRACT FROM AUTHOR]

Ten different Saccharomyces cerevisiae strains fermented semi-synthetic musts containing a Polyphenolic and Aroma Precursor Fraction (PAF) extracted from Tempranillo grapes. Aroma compounds were studied by Gas Chromatography (GC), GC-Olfactometry and GC-Mass Spectrometry (MS), during fermentation by trapping volatilized aroma, immediately after fermentation and after accelerated aging. Volatiles lost by evaporation during fermentation are mostly fermentative compounds and not grape-related odorants. Isobutanal and some esters are mostly lost during fermentation. In many cases the impact of yeast strain is evident only after aging. Strains could be classified into 3 major clusters with marked differences in fermentative and varietal profiles. Linalool and geraniol were found to have fermentative origin. S. cerevisiae yeast strains can effectively modulate varietal aroma, likely through specific enzymatic activities acting on grape phenolic acids and norisoprenoid aroma precursors and may be specifically used to mitigate some aging-related off odours, such as massoia lactone, guaiacol or TDN.

Mutations in odorant receptor genes predict olfactory perception of common compounds in foods and flowers. Through recombination they can generate extensive combinatorial variation in sensory ability among individuals.

The present study aimed to explore the key volatile compounds (VCs) that lead to the formation of characteristic flavors in ripe Pu-erh tea (RIPT) fermented by Monascus purpureus (M. purpureus). Headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC-MS), orthogonal partial least square-discriminant analysis (OPLS-DA) were employed for a comprehensive analysis of the VCs present in RIPT fermented via different methods and were further identified by odor activity value (OAV). The VCs 1,2-dimethoxybenzene, 1,2,3-trimethoxybenzene, (E)-linalool oxide (pyranoid), methyl salicylate, linalool, β-ionone, β-damascenone were the key characteristic VCs of RIPT fermented by M. purpureus. OAV and Gas chromatography-olfactometry (GC-O) further indicated that β-damascenone was the highest contribution VCs to the characteristic flavor of RIPT fermented by M. purpureus. This study reveals the specificities and contributions of VCs present in RIPT under different fermentation methods, thus providing new insights into the influence of microorganisms on RIPT flavor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Fungal control strategies based on the use of Bacillus have emerged in agriculture as eco-friendly alternatives to replace/reduce the use of synthetic pesticides. Bacillus sp. P1 was reported as a new promising strain for control of Aspergillus carbonarius, a known producer of ochratoxin A, categorized as possible human carcinogen with high nephrotoxic potential. Grape quality can be influenced by vineyard management practices, including the use of fungal control agents. The aim of this study was to evaluate, for the first time, the quality parameters of Chardonnay grapes exposed to an antifungal Bacillus-based strategy for control of A. carbonarius, supporting findings by genomic investigations. Furthermore, genomic tools were used to confirm that the strain P1 belongs to the non-pathogenic species Bacillus velezensis and also to certify its biosafety. The genome of B. velezensis P1 harbors genes that are putatively involved in the production of volatiles and hydrolytic enzymes, which are responsible for releasing the free form of aroma compounds. In addition to promote biocontrol of phytopathogenic fungi and ochratoxins, the treatment with B. velezensis P1 did not change the texture (hardness and firmness), color and pH of the grapes. Heat map and hierarchical clustering analysis (HCA) of volatiles evaluated by GC/MS revealed that Bacillus-treated grapes showed higher levels of compounds with a pleasant odor descriptions such as 3-hydroxy-2-butanone, 2,3-butanediol, 3-methyl-1-butanol, 3,4-dihydro-β-ionone, β-ionone, dihydroactinidiolide, linalool oxide, and β-terpineol. The results of this study indicate that B. velezensis P1 presents desirable properties to be used as a biocontrol agent., Competing Interests: Declaration of competing interest The authors declare no competing interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Norisoprenoids are important aromatic volatiles contributing to the pleasant floral/fruity odor in grapes and wine. They are produced from carotenoids through the cleavage of carotenoid cleavage dioxygenases (CCDs). However, the underlying mechanisms regulating VvCCD expression remain poorly understood. In this study, we showed that VvCCD4b expression was positively correlated with the accumulation of β-damascenone, β-ionone, 6-methyl-5-hepten-2-one, geranylacetone, dihydroedulan I, and total norisoprenoids in developing grapes in two vintages from two regions. VvCCD4b was found to be principally expressed in flowers, mature leaves, and berries. Abscisic acid strongly induced the expression of this gene. Additionally, the present study preliminarily indicated that the activity of the VvCCD4b promoter was dropped under 37°C treatment and also responded to the illumination change. VvCCD4b was expressed in parallel with VvMADS4 in developing grape berries. The latter is a MADS family transcription factor and nucleus-localized protein that was captured by yeast one-hybrid. A dual-luciferase reporter assay in tobacco leaves revealed that VvMADS4 downregulated the activity of the VvCCD4b promoter. VvMADS4 overexpression in grape calli and Vitis quinquangularis Rehd. leaves repressed the VvCCD4b expression. In summary, this work demonstrates that VvCCD4b expression is positively correlated with the accumulation of norisoprenoids, and VvMADS4 is a potential negative regulator of VvCCD4b. Our results provide a new perspective for understanding the regulation of VvCCD4b expression and norisoprenoid accumulation in grapes.

Knowing in detail how the white and red wine aroma compounds behave under various storage conditions and especially at high temperature is important in order to understand the changes occurring to their sensorial character during the shelf life. The initial aim of this work was to develop and validate a fast, modern, robust, and comprehensive protocol for the quantification of 64 primary, secondary, and tertiary volatile compounds by using solid-phase extraction (SPE) cartridges in sample preparation and fast GC-MS/MS (gas chromatography-tandem mass spectrometry assay) in analysis. The protocol was applied to a study of the behavior of seven Gewürztraminer and seven Teroldego wines stored in anoxia at 50 °C for 2.5 and 5 weeks. The results demonstrated a sharp decrease of the main linear terpenes linalool, geraniol, and nerol and the consequent increase of the cyclic ones, such as α-terpineol and 1,8-cineole; the increase of the C13-norisoprenoids 1,1,6,-trimethyl-1,2-dihydronapthalene (TDN), and β-damascenone and the C10 norisoprenoid safranal; the hydrolysis of acetates and linear esters; and the increase of some branched-chain esters. In red wines, a moderate increase was observed for some lactones. Some unwanted compounds, such as 2-aminoacetophenone (2-AAP), showed a notable increase in some Gewürztraminer wines, exceeding the olfactory threshold.

Norisoprenoids are important aromatic volatiles contributing to the pleasant floral/fruity odor in grapes and wine. They are produced from carotenoids through the cleavage of carotenoid cleavage dioxygenases (CCDs). However, the underlying mechanisms regulating VvCCD expression remain poorly understood. In this study, we showed that VvCCD4b expression was positively correlated with the accumulation of β-damascenone, β-ionone, 6-methyl-5-hepten-2-one, geranylacetone, dihydroedulan I, and total norisoprenoids in developing grapes in two vintages from two regions. VvCCD4b was found to be principally expressed in flowers, mature leaves, and berries. Abscisic acid strongly induced the expression of this gene. Additionally, the present study preliminarily indicated that the activity of the VvCCD4b promoter was dropped under 37°C treatment and also responded to the illumination change. VvCCD4b was expressed in parallel with VvMADS4 in developing grape berries. The latter is a MADS family transcription factor and nucleus-localized protein that was captured by yeast one-hybrid. A dual-luciferase reporter assay in tobacco leaves revealed that VvMADS4 downregulated the activity of the VvCCD4b promoter. VvMADS4 overexpression in grape calli and Vitis quinquangularis Rehd. leaves repressed the VvCCD4b expression. In summary, this work demonstrates that VvCCD4b expression is positively correlated with the accumulation of norisoprenoids, and VvMADS4 is a potential negative regulator of VvCCD4b. Our results provide a new perspective for understanding the regulation of VvCCD4b expression and norisoprenoid accumulation in grapes. [ABSTRACT FROM AUTHOR]

Climate change with rising temperatures and the unpredictability of rainy events during ripening leads to tough challenges for the winemakers in preserving the quality of white grape varieties. Grape quality is a complex concept that mainly refers to berry chemical composition, including secondary metabolites such as aroma compounds that in white berries play a key role in the identity of the wine. Terpenes, thiols, C13-norisoprenoids, methoxypyrazines, and nonterpenic alcohols are the most important aroma compounds in white grapes and several of them can be found as free volatiles or bound as glycoconjugate molecules. Agronomic practices in vineyards, such as biostimulant application, irrigation, defoliation, training systems, foliar fertilization, and bunch thinning, can have a positive effect on their concentration. This review aims to highlight the aromatic characteristics of the most utilized white grape cultivars and focus on agronomic techniques in the vineyard to enhance, implement, and intensify their aromatic characteristics. The purpose of this review paper is therefore to investigate the state of the art regarding the exaltation of aroma in white grapes in the scientific literature through sustainable agronomic techniques, but further future investigations are considered necessary given the uncertainty concerning some mechanisms of biosynthesis and their correlation with such agronomic practices.

To elucidate the significant influence of microorganisms on geographically dependent flavor formation by analyzing microbial communities and volatile flavor compounds (VFCs) in cigar tobacco leaves (CTLs) obtained from China, Dominica, and Indonesia. Microbiome analysis revealed that the predominant bacteria in CTLs were Staphylococcus, Aerococcus, Pseudomonas, and Lactobacillus, while the predominant fungi were Aspergillus, Wallemia, and Sampaiozyma. The microbial communities of CTLs from different origins differed to some extent, and the diversity and abundance of bacteria were greater than fungi. Metabolomic analysis revealed that 64 VFCs were identified, mainly ketones, of which 23 VFCs could be utilized to identify the geographical origins of CTLs. Sixteen VFCs with OAV greater than 1, including cedrol, phenylacetaldehyde, damascone, beta-damascone, and beta-ionone, play important roles in shaping the flavor profile of CTLs from different origins. Combined with the correlation analysis, bacterial microorganisms were more closely related to key VFCs and favored a positive correlation. Bacillus, Vibrio, and Sphingomonas were the main flavor-related bacteria. The study demonstrated that the predominant microorganisms were essential for the formation of key flavor qualities in CTLs, which provided a theoretical reference for flavor control of CTLs by microbial technology. KEY POINTS: • It is the high OAV VFCs that determine the flavor profile of CTLs. • The methylerythritol phosphate (MEP) pathway and the carotenoid synthesis pathway are key metabolic pathways for the formation of VFCs in CTLs. • Microbial interactions influence tobacco flavor, with bacterial microorganisms contributing more to the flavor formation of CTLs., (© 2024. The Author(s).)

Photoaging is widely regarded as the most significant contributor to skin aging damage. It is triggered by prolonged exposure to ultraviolet (UV) light and typically manifests as dryness and the formation of wrinkles. Nutritional intervention is a viable strategy for preventing and treating skin photoaging. In previous studies, we demonstrated that α-ionone had ameliorating effects on photoaging in both epidermal keratinocytes and dermal fibroblasts. Here, we investigated the potential anti-photoaging effects of dietary α-ionone using a UVB-irradiated male C57BL/6N mouse model. Our findings provided compelling evidence that dietary α-ionone alleviates wrinkle formation, skin dryness, and epidermal thickening in chronic UVB-exposed mice. α-Ionone accumulated in mouse skin after 14 weeks of dietary intake of α-ionone. α-Ionone increased collagen density and boosted the expression of collagen genes, while attenuating the UVB-induced increase of matrix metalloproteinase genes in the skin tissues. Furthermore, α-ionone suppressed the expression of senescence-associated secretory phenotypes and reduced the expression of the senescence marker p21 and DNA damage marker p53 in the skin of UVB-irradiated mice. Transcriptome sequencing results showed that α-ionone modifies gene expression profiles of skin. Multiple pathway enrichment analyses on both the differential genes and the entire genes revealed that α-ionone significantly affects multiple physiological processes and signaling pathways associated with skin health and diseases, of which the p53 signaling pathway may be the key signaling pathway. Taken together, our findings reveal that dietary α-ionone intervention holds promise in reducing the risks of skin photoaging, offering a potential strategy to address skin aging concerns.

Carotenoids are susceptible to degrading processes initiated by oxidative cleavage reactions mediated by Carotenoid Cleavage Dioxygenases that break their backbone, leading to products called apocarotenoids. These carotenoid-derived metabolites include the phytohormones abscisic acid and strigolactones, and different signaling molecules and growth regulators, which are utilized by plants to coordinate many aspects of their life. Several apocarotenoids have been recruited for the communication between plants and arbuscular mycorrhizal (AM) fungi and as regulators of the establishment of AM symbiosis. However, our knowledge on their biosynthetic pathways and the regulation of their pattern during AM symbiosis is still limited. In this study, we generated a qualitative and quantitative profile of apocarotenoids in roots and shoots of rice plants exposed to high/low phosphate concentrations, and upon AM symbiosis in a time course experiment covering different stages of growth and AM development. To get deeper insights in the biology of apocarotenoids during this plant-fungal symbiosis, we complemented the metabolic profiles by determining the expression pattern of CCD genes, taking advantage of chemometric tools. This analysis revealed the specific profiles of CCD genes and apocarotenoids across different stages of AM symbiosis and phosphate supply conditions, identifying novel reliable markers at both local and systemic levels and indicating a promoting role of β-ionone in AM symbiosis establishment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Valentina Fiorilli reports financial support was provided by Ministry of the University and Research (MUR). Salim Al-Babili reports financial support was provided by King Abdullah University of Science and Technology. Marco Giovannetti reports financial support was provided by University of Padua. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

β-Ionone and β-cyclocitral are two typical components in cyanobacterial volatiles, which can poison aquatic plants and even cause death. To reveal the toxic mechanisms of the two compounds on aquatic plants through programmed cell death (PCD), the photosynthetic capacities, caspase-3-like activity, DNA fragmentation and ladders, as well as expression of the genes associated with PCD in Lemna turionifera were investigated in exposure to β-ionone (0.2 mM) and β-cyclocitral (0.4 mM) at lethal concentration. With prolonging the treatment time, L. turionifera fronds gradually died, and photosynthetic capacities gradually reduced and even disappeared at the 96 th h. This demonstrated that the death process might be a PCD rather than a necrosis, due to the gradual loss of physiological activities. When L. turionifera underwent the death, caspase-3-like was activated after 3 h, and reached to the strongest activity at the 24 th h. TUNEL-positive nuclei were detected after 12 h, and appeared in large numbers at the 48 th h. The DNA was cleaved by Ca 2+ -dependent endonucleases and showed obviously ladders. In addition, the expression of 5 genes (TSPO, ERN1, CTSB, CYC, and ATR) positively related with PCD initiation was up-regulated, while the expression of 2 genes (RRM2 and TUBA) negatively related with PCD initiation was down-regulated. Therefore, β-ionone and β-cyclocitral can poison L. turionifera by adjusting related gene expression to trigger PCD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Compared with traditional tedious organic solvent-assisted separation process in natural medicinal chemistry, cytomembrane (CM) fishing technique became a more appealing and greener choice for screening bioactive components from natural products. However, its large-scale practical value was greatly weakened by the easy fall-off of CMs from magnetic supports, rooted in the instability of common Fe 3 O 4 particles and their insufficient interaction with CMs. In this research, a new green biostable platform was developed for drug screening through the integration of hyperbranched quaternized hydrothermal magnetic carbon spheres (HQ-HMCSs) and CMs. The positive-charged HQ-HMCSs were constructed by chitosan-based hydrothermal carbonization onto Fe 3 O 4 nanospheres and subsequent aqueous hyperbranching quaternization with 1,4-butanediol diglycidyl ether and methylamine. The strong interaction between HQ-HMCSs and CMs was formed via electrostatic attraction of HQ-HMCSs to negative-charged CMs and covalent linkage derived from the epoxy-amine addition reactions. The chemically stable HMCSs and its integration with CMs contributed to dramatically higher stability and recyclability of bionic nanocomposites. With the fishing of osteoblast CMs integrated HQ-HMCSs, two novel potential anti-osteoporosis compounds, narcissoside and beta-ionone, were discovered from Hippophae rhamnoides L. Enhanced osteoblast proliferation, alkaline phosphatase, and mineralization levels proved their positive osteogenesis effects. Preliminary pharmacological investigation demonstrated their potential action on membrane proteins of estrogen receptor alpha and insulin-like growth factor 1. Furthermore, beta-ionone showed apparent therapeutic effects on osteogenic lesions in zebrafish. These results provide a green, stable, cost-efficient, and reliable access to rapid discovery of drug leads, which verifiably benefits the design of nanocarbon-based biocomposites with increasingly advanced functionality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financialinterestsor personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Proteorhodopsins are widely distributed photoreceptors from marine bacteria. Their discovery revealed a high degree of evolutionary adaptation to ambient light, resulting in blue- and green-absorbing variants that correlate with a conserved glutamine/leucine at position 105. On the basis of an integrated approach combining sensitivity-enhanced solid-state nuclear magnetic resonance (ssNMR) spectroscopy and linear-scaling quantum mechanics/molecular mechanics (QM/MM) methods, this single residue is shown to be responsible for a variety of synergistically coupled structural and electrostatic changes along the retinal polyene chain, ionone ring, and within the binding pocket. They collectively explain the observed color shift. Furthermore, analysis of the differences in chemical shift between nuclei within the same residues in green and blue proteorhodopsins also reveals a correlation with the respective degree of conservation. Our data show that the highly conserved color change mainly affects other highly conserved residues, illustrating a high degree of robustness of the color phenotype to sequence variation.

Sweet potato provides rich nutrients and bioactive substances for the human diet. In this study, the volatile organic compounds of five pigmented-fleshed sweet potato cultivars were determined, the characteristic aroma compounds were screened, and a correlation analysis was carried out with the aroma precursors. In total, 66 volatile organic compounds were identified. Terpenoids and aldehydes were the main volatile compounds, accounting for 59% and 17%, respectively. Fifteen compounds, including seven aldehydes, six terpenes, one furan, and phenol, were identified as key aromatic compounds for sweet potato using relative odor activity values (ROAVs) and contributed to flower, sweet, and fat flavors. The OR sample exhibited a significant presence of trans -β-Ionone, while the Y sample showed high levels of benzaldehyde. Starch, soluble sugars, 20 amino acids, and 25 fatty acids were detected as volatile compounds precursors. Among them, total starch (57.2%), phenylalanine (126.82 ± 0.02 g/g), and fatty acids (6.45 μg/mg) were all most abundant in Y, and LY contained the most soluble sugar (14.65%). The results of the correlation analysis revealed the significant correlations were identified between seven carotenoids and trans -β-Ionone, soluble sugar and nerol, two fatty acids and hexanal, phenylalanine and 10 fatty acids with benzaldehyde, respectively. In general, terpenoids and aldehydes were identified as the main key aromatic compounds in sweet potatoes, and carotenoids had more influence on the aroma of OR than other cultivars. Soluble sugars, amino acids, and fatty acids probably serve as important precursors for some key aroma compounds in sweet potatoes. These findings provide valuable insights for the formation of sweet potato aroma.

Endophytic fungi in flowers influence plant health and reproduction. However, whether floral volatile organic compounds (VOCs) affect the composition and function of the endophytic fungal community remains unclear. Here, gas chromatography-mass spectrometry (GC-MS) and high-throughput sequencing were used to explore the relationship between floral VOCs and the endophytic fungal community during different flower development stages in Osmanthus fragrans 'Rixiang Gui'. The results showed that the composition of the endophytic fungal community and floral VOCs shifted along with flowering development. The highest and lowest α diversity of the endophytic fungal community occurred in the flower fading stage and full blooming stage, respectively. The dominant fungi, including Dothideomycetes (class), Pleosporales (order), and Neocladophialophora , Alternaria , and Setophoma (genera), were enriched in the flower fading stage and decreased in the full blooming stage, demonstrating the enrichment of the Pathotroph, Saprotroph, and Pathotroph-Saprotroph functions in the flower fading stage and their depletion in the full blooming stage. However, the total VOC and terpene contents were highest in the full blooming stage and lowest in the flower fading stage, which was opposite to the α diversity of the endophytic fungal community and the dominant fungi during flowering development. Linalool, dihydro-β-ionone, and trans -linalool oxide(furan) were key factors affecting the endophytic fungal community composition. Furthermore, dihydro-β-ionone played an extremely important role in inhibiting endophytic fungi in the full blooming stage. Based on the above results, it is believed that VOCs, especially terpenes, changed the endophytic fungal community composition in the flowers of O. fragrans 'Rixiang Gui'. These findings improve the understanding of the interaction between endophytic fungi and VOCs in flowers and provide new insight into the mechanism of flower development.

Carotenoids are isoprenoid pigments indispensable for photosynthesis. Moreover, they are the precursor of apocarotenoids, which include the phytohormones abscisic acid (ABA) and strigolactones (SLs) as well as retrograde signaling molecules and growth regulators, such as β-cyclocitral and zaxinone. Here, we show that the application of the volatile apocarotenoid β-ionone (β-I) to Arabidopsis plants at micromolar concentrations caused a global reprogramming of gene expression, affecting thousands of transcripts involved in stress tolerance, growth, hormone metabolism, pathogen defense, and photosynthesis. This transcriptional reprogramming changes, along with induced changes in the level of the phytohormones ABA, jasmonic acid, and salicylic acid, led to enhanced Arabidopsis resistance to the widespread necrotrophic fungus Botrytis cinerea (B.c.) that causes the gray mold disease in many crop species and spoilage of harvested fruits. Pre-treatment of tobacco and tomato plants with β-I followed by inoculation with B.c. confirmed the effect of β-I in increasing the resistance to this pathogen in crop plants. Moreover, we observed reduced susceptibility to B.c. in fruits of transgenic tomato plants overexpressing LYCOPENE β-CYCLASE, which contains elevated levels of endogenous β-I, providing a further evidence for its effect on B.c. infestation. Our work unraveled β-I as a further carotenoid-derived regulatory metabolite and indicates the possibility of establishing this natural volatile as an environmentally friendly bio-fungicide to control B.c., (© 2023 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.)

Four rare compounds (1-4), including one 1,4-epoxy-benzoxepane derivative and one ringed prenylated naphthoquinoid skeleton, as well as one isopimarane-type diterpenoid and one megastigmane-type glycoside, along with three known megastigmane-type glycosides (5-7) were isolated from the ethanol extracts of C. chinense. Their structures were determined on the basis of 1D, 2D NMR, HR-ESI-MS and DP4+ analysis. Meanwhile, the in vitro evaluation indicated that compound 2 and 6 exhibited excellent procoagulant activities, which can significantly shorten prothrombin time (PT) and activated partial thromboplastin time (APTT), respectively., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Norisoprenoids are produced from carotenoids under oxidative degradation mediated by carotenoid cleavage dioxygenases (CCDs) and contribute to floral and fruity notes in grape berries and wine. The diversity of CCD substrates and products has been demonstrated by in vitro recombinant proteins extracted from Escherichia coli expressing CCD genes and of in vivo proteins in an E. coli system co-expressing genes for carotenoid synthesis and cleavage. In the current study, VvCCD1 and VvCCD4b were isolated from the cDNA library of Vitis vinifera L. cv. Cabernet Sauvignon and then transformed into carotenoid-accumulating recombinant Saccharomyces cerevisiae strains. The expression of the target genes was monitored during the yeast growth period, and the accumulation of carotenoids and norisoprenoids in the recombinant strains was measured. The results indicated that both of the VvCCDs cleaved β-carotene at the 7, 8 (7′, 8′) position into β-cyclocitral for the first time. Additionally, the two enzymes also degraded β-carotene at the 9, 10 (9′, 10′) position to generate β-ionone and cleaved lycopene at the 5, 6 (5′, 6′) position into 6-methyl-5-hepten-2-one. These findings suggested that the VvCCDs may possess more cleavage characteristics under the eukaryotic expression system in S. cerevisiae than the prokaryotic system in E. coli, which could better explain the biochemical functions of VvCCDs in grape berries. [ABSTRACT FROM AUTHOR]

Highlights • Glycosidically bound and free form volatiles identified within off-vine Vidal. • Cluster analysis and volcano plot were jointly used for holistic analysis of volatiles. • Off-vine grapes accumulated more 2-phenylalanol than on-vine grapes. • Off-vine treatment can induce upregulation effects on some higher alcohols. Abstract We investigated the dynamic changes in norisoprenoids and phenylalanine derivatives in off-vine Vidal blanc. Glycosidically bound as well as free-form volatile compounds were identified by GC–MS in two vintages. Thus, off-vine grape exhibited the development of four higher alcohols (viz. linalool oxide, 2-octanol, 1-pentanol, and 1-heptanol), C13-norisoprenoids (α-ionone), phenylalanine-derivates (2-phenylethanol), whereas β-ionone and geranial showed high correlation in on-vine grape. Freeze-thaw cycles and desiccation, two exterior stress affect volatile compound development, resulted in content fluctuations during late harvest. Interestingly, the total content of higher alcohols was higher in on-vine grapes than off-vine grapes in two vintages respectively. Interestingly, the content of higher alcohols was higher in off-vine samples in the 2016 and 2017 vintages. In terms of physicochemical parameters, off-vine Vidal showed results similar to those of on-vine sample. Nevertheless, sensorial impression of the grape juice was influenced by interaction of vintages and vine treatments. [ABSTRACT FROM AUTHOR]

Cluster thinning (CT) is a common practice to prevent overcropping in viticulture. CT affects vine balance between vegetative and productive growth and further modifies grape composition. This study investigated the effects of cluster thinning treatments applied at pea-size stage (CT-AF) and the onset of veraison (CT-V), respectively, on volatile compounds of Cabernet Sauvignon in two seasons (2013–2014). The experimental vineyard was located in the north-west of China with semi-arid and monsoon climate. CT exhibited limited effects on the evolutions of volatile compounds. CT-AF exhibited an inhibition on 6-methyl-5-heptene-2-one accumulation. There were no differences in terpene concentrations between CT-treated and control grapes regardless of CT time. Regarding C 6 /C 9 compounds and their derivatives, CT-AF decreased nonanal concentration whilst CT-V increased (Z)-3-hexen-1-ol concentration. Additionally, there were increases in nonanal, (E)-2-hexen-1-ol, (Z)-2-hexen-1-ol and (Z)-3-hexen-1-ol concentrations in grapes with delayed CT. Among benzene derivatives, earlier CT resulted in lower phenol concentrations. Unlabelled Image • Effects of cluster thinning (CT) on volatiles compounds in grapes were evaluated. • CT had limited effects on the evolution of volatile compounds. • CT applied at pea-size stage inhibited 6-methyl-5-heptene-2-one accumulation. • CT modified the concentrations of C 6 /C 9 compounds and their derivatives. • Phenol was negatively responsive to CT applied at pea-size stage. [ABSTRACT FROM AUTHOR]

One new norisoprenoid 3,9-dihydroxy dihydro actinidiolide (1), together with eleven known compounds (2–12), were isolated from ethanol extract of the leaves of Ficus pumila collected in Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1, 2, 4, 5, 8 and 10–12 were isolated from the F. pumila for the first time. All compounds were evaluated for their cytotoxic activity. Compounds 3 and 9 showed weak cytotoxic activity against Hela, MCF-7 and A549 cell lines. [ABSTRACT FROM AUTHOR]

Summary: One of the major challenges in chemical synthesis is the selective oxyfunctionalization of non‐activated C‐H bonds, which can be enabled by biocatalysis using cytochrome P450 monooxygenases. In this study, we report on the characterization of the versatile CYP109Q5 from Chondromyces apiculatus DSM436, which is able to functionalize a wide range of substrates (terpenes, steroids and drugs), including the ring of β‐ionone in non‐allylic positions. The crystal structure of CYP109Q5 revealed flexibility within the active site pocket that permitted the accommodation of bulky substrates, and enabled a structure‐guided approach to engineering the enzyme. Some variants of CYP109Q5 displayed a switch in selectivity towards the non‐allylic positions of β‐ionone, allowing the simultaneous production of 2‐ and 3‐hydroxy‐β‐ionone, which are chemically challenging to synthesize and are important precursors for carotenoid synthesis. An efficient whole‐cell system finally enabled the production of up to 0.5 g l−1 hydroxylated products of β‐ionone; this system can be applied to product identification in further biotransformations. Overall, CYP109Q5 proved to be highly evolvable and active. The studies in this work demonstrate that, using rational mutagenesis, the highly versatile CYP109Q5 generalist can be progressively evolved to be an industrially valuable specialist for the synthesis of specific products. Here, we report on the identification, expression, biochemical and structural characterization as well as enzyme engineering of CYP109Q5 from the myxobacterium Chondromyces apiculatus DSM436. Overall, CYP109Q5 exhibits a versatile substrate spectra, high activities as E. coli whole‐cell biocatalyst and has shown to be highly evolvable. In addition, even non‐allylic positions of the norisoprenoid β‐ionone could be oxyfunctionalized. Thus, CYP109Q5 is highly interesting for future industrial applications. [ABSTRACT FROM AUTHOR]

Abstract Merlot and Traminer (Vitis vinifera L.) grapes were subjected to gamma irradiation at the panoramic 60Co source at four doses (670, 1300, 2000, 2700 Gy) and wines were produced from the irradiated grapes. HPLC analysis of musts have shown a negative impact of irradiation on the amino acids content. However, Merlot wines produced from irradiated grapes demonstrated better extraction of the coloring matter. The concentrations of anthocyanins increased with the increasing absorbed irradiation dose, while flavonols and flavanols were not affected by irradiation. Irradiation with doses up to 2000 Gy increased concentrations of fruity-floral aroma compounds, especially monoterpens and C13 norisoprenoids in wines, while a maximal dose of 2700 Gy expressed more the toasty and caramel notes due to higher concentrations of furfural and furfuryl alcohols. Results obtained suggest that ionizing irradiation might be a suitable method for grape treatment since better chemical properties in wine could be achieved. Highlights • Gamma irradiation had negative impact on amino acids content in grapes. • Better extraction of coloring matter was obtained from irradiated grapes. • Flavonols and flavan-3-ols were not affected by irradiation. • Aroma profile of wines from irradiated grapes was enhanced. • The irradiation dose up to 2000 Gy increased fruity-floral aroma in wine. [ABSTRACT FROM AUTHOR]

Highlights • The effect of elicitation on grape volatile composition had been little studied. • 3 elicitors were assayed: methyl jasmonate-MeJ, chitosan-CHT, a yeast extract-YE. • Sum of terpenes, C 13- norisoprenoids, benzenoids and esters was the lowest in MeJ and CHT. • Total C6 compounds content in grapes treated with MeJ and CHT was the highest. • YE application scarcely affected volatile compounds respect to control samples. Abstract Elicitors play a key role against pathogen infestation, becoming as an alternative to chemical pesticides by the improving secondary metabolites synthesis. Their effect on grape volatile compounds has been little investigated. This field trial aimed to study the foliar application of methyl jasmonate (MeJ), chitosan (CHT), and a yeast extract (YE) on grape volatile compounds by HS-SPME-GC–MS. The results showed that, in general, foliar elicitor application decreased the synthesis of grape volatile compounds. Depending of the treatment, MeJ and CHT showed the lowest total amounts of terpenoids, C 13 norisoprenoids, benzenoids, and esters, together with the highest levels of C6 compounds. YE treatment applied to the grapevines barely affected the synthesis of volatile compounds in grapes. The importance of this work is to add information about the effects of elicitors on grape volatile composition in Tempranillo grapevines. [ABSTRACT FROM AUTHOR]