Dataset Information

Fruit softening: evidence for pectate lyase action in vivo in date (Phoenix dactylifera) and rosaceous fruit cell walls.

ABSTRACT:

Background and aims

The programmed softening occurring during fruit development requires scission of cell-wall polysaccharides, especially pectin. Proposed mechanisms include the action of wall enzymes or hydroxyl radicals. Enzyme activities found in fruit extracts include pectate lyase (PL) and endo-polygalacturonase (EPG), which, in vitro, cleave de-esterified homogalacturonan in mid-chain by β-elimination and hydrolysis respectively. However, the important biological question of whether PL exhibits action in vivo had not been tested.

Methods

We developed a method for specifically and sensitively detecting in-vivo PL products, based on Driselase digestion of cell-wall polysaccharides and detection of the characteristic unsaturated product of PL action.

Key results

In model in-vitro experiments, pectic homogalacturonan that had been partially cleaved by commercial PL was digested to completion with Driselase, releasing an unsaturated disaccharide ('ΔUA-GalA'), taken as diagnostic of PL action. ΔUA-GalA was separated from saturated oligogalacturonides (EPG products) by electrophoresis, then subjected to thin-layer chromatography (TLC), resolving ΔUA-GalA from higher homologues. The ΔUA-GalA was confirmed as 4-deoxy-β-l-threo-hex-4-enopyranuronosyl-(1➝4)-d-galacturonic acid by NMR spectroscopy. Driselase digestion of cell walls from ripe fruits of date (Phoenix dactylifera), pear (Pyrus communis), rowan (Sorbus aucuparia) and apple (Malus pumila) yielded ΔUA-GalA, demonstrating that PL had been acting in vivo in these fruits prior to harvest. Date-derived ΔUA-GalA was verified by negative-mode mass spectrometry, including CID fragmentation. The ΔUA-GalA : GalA ratio from ripe dates was roughly 1:20 (mol/mol), indicating that ~5% of the bonds in endogenous homogalacturonan had been cleaved by in-vivo PL action.

Conclusions

The results provide the first demonstration that PL, previously known from studies of fruit gene expression, proteomic studies and in-vitro enzyme activity, exhibits enzyme action in the walls of soft fruits and may thus be proposed to contribute to fruit softening.

SUBMITTER: Al Hinai TZS

PROVIDER: S-EPMC8422893 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Due to its nutritional value and health benefits, the date palm (Phoenix dactylifera L.) is an essential dietary food crop throughout Middle Eastern and African countries. Consumers are concerned about the possible microbial contamination of dates, especially since most dates arriving in local markets are unprocessed. The absence of processing increases the possibility of microbial contamination, which raises the probability of microbial contamination. This study aims to analyze and evaluate the variability of fungal and bacterial microbiota identified in the most popular date palm fruits in Saudi Arabia. The study assessed ten date variety fruits from the most popular date palm varieties for consumption in Saudi Arabia and analyzed the microbial count. Morphological and molecular characterization and comparison of nuclear ribosomal DNA internal transcribed spacer (ITS) sequences identified 78 fungi, including 36 distinct species across 15 fungal genera. Alternaria, Fusarium, Curvilaria, Aspergillus, and Penicillium were the most frequent genera among the ten fruit cultivars studied, according to ITS-rDNA sequence analysis. Furthermore, 36 bacterial isolates were obtained from ten date varieties studied, each with a unique colony morphology. These isolates were identified based on sequence alignment and comparison of their 16S rDNA internal spacer regions to those available in public databases. The results showed that the bacterial isolates included 15 species from five bacterial genera. The results suggested that Bacillus, Stenotrophomonas, and Brucella were the prevailing genera among the ten tested fruit varieties. Some bacterial genera, such as Brucella, Achromobacter, and Stenotrophomonas, are well-known potential human pathogens. Chaetomium globosum was also recognized as air pollution causing adverse health effects such as allergies and as the causal agent of human fungal infections among the tested date varieties; the Rashodiah type exhibited the highest fungal contamination, whereas the Sagai variety displayed the lowest fungal contamination. Conversely, the Sukkari, Barhi, and Mejdool varieties were the most contaminated with bacteria among the ten tested varieties, while the Khalas variety showed the least bacterial contamination. To the best of the authors' knowledge, this study provides the initial comprehensive account of the molecular and morphological identification of all fungal and bacterial genera associated with date palm (P. dactylifera) fruits.

Project description:Date palm (Phoenix dactylifera) is considered to be a highly important food crop in several African and Middle Eastern countries due to its nutritional value and health-promoting properties. Microbial contamination of dates has been of concern to consumers, but very few works have analyzed in detail the microbial load of the different parts of date fruit. In the present work, we characterized the fungal communities of date fruit using a metagenomic approach, analyzing the data for differences between microbial populations residing in the pulp and peel of "Medjool" dates at the different stages of fruit development. The results revealed that Penicillium, Cladosporium, Aspergillus, and Alternaria were the most abundant genera in both parts of the fruit, however, the distribution of taxa among the time points and tissue types (peel vs. pulp) was very diverse. Penicillium was more abundant in the pulp at the green developmental stage (Kimri), while Aspergillus was more frequent in the peel at the brown developmental stage (Tamer). The highest abundance of Alternaria was detected at the earliest sampled stage of fruit development (Hababauk stage). Cladosporium had a high level of abundance in peel tissues at the Hababauk and yellow (Khalal) stages. Regarding the yeast community, the abundance of Candida remained stable up until the Khalal stage, but exhibited a dramatic increase in abundance at the Tamer stage in peel tissues, while the level of Metschnikowia, a genus containing several species with postharvest biocontrol activity, exhibited no significant differences between the two tissue types or stages of fruit development. This work constitutes a comprehensive metagenomic analysis of the fungal microbiome of date fruits, and has identified changes in the composition of the fungal microbiome in peel and pulp tissues at the different stages of fruit development. Notably, this study has also characterized the endophytic fungal microbiome present in pulp tissues of dates.

Project description:BackgroundThe rate of cesarean section is increasing in all over the world with different drafts in various countries. This growth increases unpleasant outcomes of delivery. Recent studies explained the benefits of date palm fruit on labor process improvement. Date fruit can be considered as a factor for increasing vaginal delivery and also reducing the frequency of caesarean section in order to prevent its great complications. This systematic review has been designed to review clinical studies that investigate the effects of date palm fruit on labor outcomes (duration of labor stages, bishop score, and frequency of cesarean section) compared with routine cares.MethodsThis study was performed in 2019. Required data has been collected from electronic databases and manual searches. All randomized clinical trials evaluating the effects of date palm fruit on labor and delivery that were published from January 2000 to August 2019 in English and Persian languages, were incorporated in this systematic review. The methodological quality of the included studies was evaluated according to the risk of bias assessment of Cochrane handbook of systematic reviews, and were then reported using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement.ResultsEight studies were included in the qualitative and quantitative synthesis. Meta-Analysis showed that date fruit consumption can significantly reduce active phase of labor (three trials with 380 participants; (MD = - 109.3, 95%CI (- 196.32, - 22.29; I2 = 89%), P = 0.01), and also it can significantly improve the bishop score (two trials with 320 participants; MD = 2.45, 95%CI (1.87, 3.04; I2 = 0%), P < 0.00001). Date fruit consumption had no effects on the duration of first, second, and third stages of labor, and the frequency of cesarean section.ConclusionDate can reduce the duration of active phase and improve the bishop score; however, due to from the low to mediate quality of the studies; it seems that the other studies are needed to prove these results better than this.