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Abstract Prohexadione-Calcium (Pro-Ca) plays key roles in improving fruit quality and yield by regulating various aspects of plant growth. However, the effects of how Pro-Ca regulates the regulation of sugar and acid balance and its impact on the production of volatile aroma substances during fruit growth and development are poorly understood. In this study, the Pro-Ca solutions developed at concentrations of 200, 400, 600 and 800 mg·L-1 were sprayed on the entire “Chardonnay” grape tree 22, 42, 62 and 82 days after initial flowering. The values of endogenous hormones, sugar and acid content, enzyme activities and flavor content were then measured in grapes 45, 65, 85 and 105 days (ripeness stage) after the initial flowering. The results showed that Pro-Ca had significant effects on fruits during development, including reducing ABA content, increasing ZT, GA3 and IAA levels, promoting fruit ripening and enhancing enzymes, which are involved in sugar and acid synthesis. Consequently, these effects led to an increase in sugar and acid content in the berries. Particularly during the ripening phase, the application of 600 mg L-1 Pro-Ca resulted in an increase in soluble sugar content of 11.28% and a significant increase in citric acid and malic acid content of 97.80% and 68.86%, respectively. Additionally, Pro-Ca treatment enhanced both the variety and quantity of aroma compounds present in the berries, with the 600 mg·L-1 Pro-Ca treatment showcasing the most favorable impact on volatile aroma compounds in ‘Chardonnay’ grapes. The levels of aldehydes, esters, alcohols, phenols, acids, ketones, and terpenes were significantly higher under the 600 mg·L-1 Pro-Ca treatment compared to those of control with 51.46 − 423.85% increase. In conclusion, Pro-Ca can regulate the content of endogenous hormones and the activities of enzymes related to sugar and acid metabolism in fruit, thereby increasing the content of soluble sugar and organic acid in fruit and the diversity and concentration of fruit aroma substances. Among them, foliar spraying 600 mg · L-1 Pro-Ca has the best effect. In the future, we need to further understand the molecular mechanism of Pro-Ca in grape fruit to lay a solid foundation for quality improvement breeding.

Vitamin D is a lipid soluble steroid hormone, which plays a critical role in the calcium homeostasis, neuronal development, cellular differentiation, and growth by binding to vitamin D receptor (VDR). Associations between VDR gene polymorphism and Alzheimer’s disease (AD), Parkinson’s disease (PD), and mild cognitive impairment (MCI) risk has been investigated extensively, but the results remain ambiguous. The aim of this study was to comprehensively assess the correlations between four VDR polymorphisms (FokI, BsmI, TaqI, and ApaI) and susceptibility to AD, PD, and MCI. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to determine the relationship of interest. Pooled analyses suggested that the ApaI polymorphism decreased the overall AD risk, and the TaqI increased the overall PD susceptibility. In addition, the BsmI and ApaI polymorphisms were significantly correlated with the overall MCI risk. Stratified analysis by ethnicity further showed that the TaqI and ApaI genotypes reduced the AD predisposition among Caucasians, while the TaqI polymorphism enhanced the PD risk among Asians. Intriguingly, carriers with the BB genotype significantly decreased the MCI risk in Asian descents, and the ApaI variant elevated the predisposition to MCI in Caucasians and Asians. Further studies are need to identify the role of VDR polymorphisms in AD, PD, and MCI susceptibility.

Abstract Background Low temperature (LT) is one of the main limiting factors that affect growth and development in grape. Increasing soluble sugar and scavenging reactive oxygen species (ROS) play critical roles in grapevine resistance to cold stress. However, the mechanism of β-amylase (BAM) involved in the regulation of sugar levels and antioxidant enzyme activities in response to cold stress is unclear. Results In this study, six BAM genes were identified and clustered into four groups. Multiple sequence alignment and gene structure analysis showed that VvBAM6 lacked the Glu380 residue and contained only an exon. The transcript abundance of VvBAM1 and VvBAM3 significantly increased as temperature decreased. After LT stress, VvBAM1 was highly expressed in the leaves, petioles, stems, and roots of overexpressing tomato lines. The total amylase and BAM activities increased by 6.5- and 6.01-fold in transgenic plants compared with those in wild-type tomato plants (WT) subjected to LT, respectively. The glucose and sucrose contents in transgenic plants were significantly higher than those in WT plants, whereas the starch contents in the former decreased by 1.5-fold compared with those in the latter under LT stress. The analysis of transcriptome sequencing data revealed that 541 genes were upregulated, and 663 genes were downregulated in transgenic plants. One sugar transporter protein gene (SlSTP10), two peroxidase (POD)-related genes (SlPER7 and SlPER5), and one catalase (CAT)-related gene (SlCAT1) were upregulated by 8.6-, 3.6-, 3.0-, and 2.3-fold in transgenic plants after LT stress, respectively. Conclusions Our results suggest that VvBAM1 overexpression promotes ROS scavenging and improves cold tolerance ability by modulating starch hydrolysis to affect soluble sugar levels in tomato plants.

Alcohol has been demonstrated to disrupt intestinal barrier integrity. Some flavonoid compounds that exert antioxidant activity have a protective effect on intestinal barrier function. As an important medicinal and edible plant, sea buckthorn (Hippophae) seeds are rich in flavonoids, but their protective effect on the intestinal barrier has not been reported. In our research, 76 kinds of flavonoids were identified in Hippophae rhamnoides ssp. sinensis seed residue flavonoids (HRSF) by ultra-performance liquid chromatography–tandem mass spectrometry. Kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, kaempferol-3-O-robinoside-7-O-rhamnoside, isorhamnetin-3-O-2G-rhamnosylrutinoside, quercetin-3-O-rutinoside, (−)-epigallocatechin, and B type of procyanidin were the most abundant substances, accounting for 15.276%, 15.128%, 18.328%, 10.904%, 4.596%, 5.082%, and 10.079% of all identified flavonoids, respectively. Meanwhile, pre-treatment with HRSF was able to prevent alcohol-induced disruption of intestinal barrier integrity through elevating the transepithelial monolayer resistance value, inhibiting the flux of fluorescein isothiocyanate-dextran, and upregulating the mRNA and protein level of TJs (occludin and ZO-1). Furthermore, it was also able to reverse alcohol-induced oxidative stress through suppressing the accumulation of reactive oxygen species and malondialdehyde, improving the glutathione level and superoxide dismutase activity. Finally, the results showed that HRSF pre-treatment effectively elevated the erythroid-related factor 2 mRNA and protein level compared with the alcohol-alone treatment group. Our research was the first to demonstrate that HRSF could prevent alcohol-induced intestinal barrier dysfunction through regulating the Nrf2-mediated pathway in order to attenuate oxidative stress and enhance TJ expression.

Fusarium solani is the most significant pathogen that causes root rot in wolfberry, which has led to serious economic losses in terms of production. As an important enzyme in organisms, NADPH oxidase produces ROS. However, the mechanism of ROS mediated by NADPH oxidase in the growth of F. solani has not been studied. In this study, F. solani colonies were treated with 40 µmol/L DPI and 0.0012% H2O2. The growth rate in terms of colonies, number of spores, key gene expression levels, activity of key enzymes and the content of key products of ROS metabolic pathways were determined. The results showed that the growth rate of colonies treated by DPI decreased by 19.43%, the number of macroconidia increased by 231.03%, the IOD/area values of O2− and H2O2 decreased by 34.88% and 16.97%, respectively, the expression levels in terms of NCF2, SOD1, CTA1 and PXMP4 significantly decreased and the activities of SOD, CAT and POD decreased significantly, while the MDA content increased significantly. Additionally, in the case of the colonies treated with exogenous H2O2, the MDA content decreased significantly while the other indicators increased. Taken together, the NCF2 gene is involved in regulating the activity of NADPH oxidase and regulates the products of O2− and ROS metabolism enzyme genes and their activities to affect colony growth in the F. solani growth process.

The application of elicitors enhances grape quality, especially the volatile compounds. There are few studies on the influence of elicitors on the aroma compositions of grapes. Additionally, studies on the amino acids and aroma profiles of ‘Cabernet Gernischt’ grapes are scant. The objective of this work was to evaluate the effect of benzothiadiazole (BTH) treatments on the amino acids and aroma profiles of ‘Cabernet Gernischt’ grapes during berry development. BTH was sprayed on berries at three different stages during grape development; the fruit set period, swelling, and veraison stages. Physicochemical parameters, amino acids, and aroma compounds of the grapes were evaluated. The results showed increased an weight and color quality of treated grapes, while the content of primary metabolites such as sugar and amino acids in treated grapes declined relative to control grapes. However, total concentrations of the various aroma classes were higher in treated grapes, except for carbonyls and terpenoids, which presented higher levels in control grapes than in BTH-treated grapes. The correlation analysis between amino acids and aroma compounds revealed positive correlations in both samples with few negative correlations in BTH samples. The odor activity values (OAVs) affirmed the floral, fruity, and fresh-green nature of ‘Cabernet Gernischt’ grapes. BTH application to ‘Cabernet Gernischt’ berries significantly influenced the compositional qualities of the grapes.

The enzymatic hydrolysis of compositionally well-fractionated bacterial poly-(3-hydroxybutyrate-co-3-mercaptopropionate)s [P(3HB-co-3MP)s] was investigated by extracellular poly(hydroxyalkanoate) (PHA) depolymerase isolated from Ralstonia pikettii T1. As the crystallinity of P(3HB-co-3MP)s varies with the 3MP unit content, their enzymatic hydrolysis rates show strong dependence on the 3MP unit content. Being different from the enzymatic hydrolysis behavior of poly(3-hydroxybutyrate-co-3-hydroxypropionate)s, that of P(3HB-co-3MP)s is also quite related to the poor biodegradability of thioester linkages. It is of interest to note that it is 3HB-3MP thioester linkages but not 3MP-3MP ones that can be hydrolyzed by PHB depolymerase. [ABSTRACT FROM AUTHOR]

Arginine in grape juice can be metabolized by wine yeasts and malolactic bacteria to precursors of ethyl carbamate, a known carcinogen. The aim of this study was to develop a simple, fast and accurate method for determining arginine in grape juice with Sakaguchi reaction following the separation of arginine with Amberlite 1R120 strong cation-exchange resin. Measurement was done under optimized conditions as follows: sample (mg) to cation-exchange resin (g) ratio of 0.683, sample pH 2.0, sample flow rate 0.5 mL/min, use of distilled water rinsing to avoid interference of other compounds adsorbed on the resin, and elution with 1 mol/L of NaOH solution. This method can be applied in a quick and accurate quantification of arginine in grape juice for controlling the ethyl carbamate level in wine. [ABSTRACT FROM AUTHOR]