Berry shrivel in grapevine: a review considering multiple approaches.

Grapevine berry shrivel, a ripening disorder, causes significant economic losses in the worldwide wine and table grape industries. An early interruption in ripening leads to this disorder, resulting in shriveling and reduced sugar accumulation affecting yield and fruit quality. Loss of sink strength associated with berry mesocarp cell death is an early symptom of this disorder; however, potential internal or external triggers are yet to be explored. No pathogens have been identified that might cause the ripening syndrome. Understanding the underlying causes and mechanisms contributing to berry shrivel is crucial for developing effective mitigation strategies and finding solutions for other ripening disorders associated with climacteric and non-climacteric fruits. This review discusses alterations in the fruit ripening mechanism induced by berry shrivel disorder, focusing primarily on sugar transport and metabolism, cell wall modification and cell death, and changes in the phytohormone profile. The essential open questions are highlighted and analyzed, thus identifying the critical knowledge gaps and key challenges for future research.

Identification and Analysis of MADS-Box Genes Expressed in the Mesocarp of Oil Palm Fruit (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis) is the most important tropical oil-bearing crop species worldwide. MADS-box proteins, which play crucial roles in plant growth and development and are involved in various physiological and biochemical processes, compose one of the largest families of plant transcription factors. In this study, 42 MADS-box genes were screened from the mesocarp transcriptome database of oil palm fruit, and their phylogenetic relationships with Arabidopsis thaliana MADS-box genes were analyzed. Based on the results, MADS-box genes from oil palm mesocarp were classified into four groups: MIKCc-type, MIKC*-type, Mα-type, and Mγ-type MADS-box genes. Members of the subfamilies were classified according to the presence of three specific protein motifs. To explore the differential expression of the MADS-box genes, the dynamic expression of all selected MADS-box genes in oil palm was measured by RNA-seq. The high expression of specific MADS-box genes in the mesocarp of oil palm during different developmental stages indicates that those genes may play important roles in the cell division of and metabolite accumulation in the fruit and could become important targets for fruit development and oil accumulation research in oil palm.

EgMYB108 regulates very long-chain fatty acid (VLCFA) anabolism in the mesocarp of oil palm.

KEY MESSAGE: EgMYB108 regulates VLCFA anabolism in oil palm. Very long-chain fatty acids (VLCFAs), which are fatty acids with more than 18 C, can not only be used as a form of triglyceride (TAG) but also provide precursors for the biosynthesis of cuticle wax, and they exist in plant epidermal cells in the form of wax in higher plants. However, which and how transcriptional factors (TFs) regulate this process is largely unknown in oil palm. In this study, a MYB transcription factor (EgMYB108) with high expression in the mesocarp of oil palm fruit was characterized. Overexpression of EgMYB108 promoted not only total lipid content but also VLCFA accumulation in oil palm embryoids. Subsequently, transient transformation in protoplasts and qRT-PCR analysis indicated that the EgKCS5 and EgLACS4 genes were significantly increased with the overexpression of EgMYB108. Furthermore, yeast one­hybrid assays, dual-luciferase assays and EMSAs demonstrated that EgMYB108 binds to the promoters of EgKCS5 and EgLACS4 and regulates their transcription. Finally, EgMYB108 interacts with the promoters of EgLACS and EgKCS simultaneously and finally improves the VLCFA and total lipid contents; a pathway summarizing this interaction was depicted.. The results provide new insight into the mechanism by which EgMYB108 regulates lipid and VLCFA accumulation in oil palm.

Evaluation of Two Water Deficit Models on Phenolic Profiles and Antioxidant Activities of Different Peach Fruits Parts.

The present work was designed to evaluate the effects of two water shortage strategies on the phenolic profile and antioxidants activities of four Prunus persica L. cultivars (Flordastar, Early May crest, Rubirich and O'Henry). Over the course of two successive seasons (2016 and 2017), three different irrigation strategies were tested: full irrigation (FI: 100 % crop evapotranspiration (Etc)), sustained deficit irrigation (SDI: 50 % ETc), and cyclic deficit irrigation (CDI: irrigation at 100 % field capacity with a soil moisture of 50 % field capacity). HPLC-UV/VIS profile of phenolic compounds, enzymatic and non-enzymatic antioxidant activities were assessed in exocarp and mesocarp. The results showed that deficit irrigation improved the content of phenolic compounds and the antioxidant activities. In O'Henry, ascorbate peroxidase activity increased significantly under CDI in exocarp (249 %). In conclusion, most cultivars showed an improvement of the fruit quality under SDI, whereas O'Henry fruits gathered the highest phenolic amounts and displayed the best antioxidant activity under CDI.

The Prophylactic Activity of Punica granatum L. mesocarp Protects Preadipocytes against Ribosylated BSA-Induced Toxicity.

OBJECTIVE: It was aimed at comparing the glycating capacities of glucose and ribose in bovine serum albumin (BSA) and anti-glycation activity of pomegranate mesocarp extract (PME). The protective mechanism of PME against ribosylated BSA (BSARIB)-induced toxicity was also investigated. METHODS: BSA was incubated with glucose or ribose in the presence or absence of PME for 15 days. In preadipocytes pretreated with PME, cell viability, ROS production, lipid peroxidation and mitochondrial membrane potential were investigated following 1, 6, 12, 18 and 24 h exposure to BSARIB. Nuclear translocation of NFκB was assessed at 1 h and 24 h of BSARIB insult. Accumulation of oxidized proteins, activities of intrinsic antioxidant enzymes and IL-6 secretion were also determined after 24 h exposure to BSARIB. RESULTS: Ribose was a harsher glycating agent as compared to glucose and PME showed strong anti-glycation activity by suppressing (P < 0.05) the increase in levels of fluorescent AGEs, Amadori products, protein carbonyl and advanced oxidation protein products (AOPP). In preadipocytes, BSARIB potentiated pro-apoptotic activity by inhibiting the nuclear translocation of NFκB. BSARIB induced a time dependent decrease in cell viability, which was significantly suppressed (P < 0.05) by PME. The extract also significantly reduced (P < 0.05) the time dependent increase in ROS level and associated lipid peroxidation as well as loss in mitochondrial membrane potential caused by BSARIB. PME also counteracted the BSARIB-induced accumulation of oxidized proteins, decrease in intrinsic antioxidant activity and IL-6 over-secretion. CONCLUSIONS: PME showed anti-glycation activity and afforded protection against BSARIB-induced toxicity, oxidative stress and inflammation in preadipocytes.

Characterization of Oil Palm Acyl-CoA-Binding Proteins and Correlation of Their Gene Expression with Oil Synthesis.

Acyl-CoA-binding proteins (ACBPs) are involved in binding and trafficking acyl-CoA esters in eukaryotic cells. ACBPs contain a well-conserved acyl-CoA-binding domain. Their various functions have been characterized in the model plant Arabidopsis and, to a lesser extent, in rice. In this study, genome-wide detection and expression analysis of ACBPs were performed on Elaeis guineensis (oil palm), the most important oil crop in the world. Seven E. guineensis ACBPs were identified and classified into four groups according to their deduced amino acid domain organization. Phylogenetic analysis showed conservation of this family with other higher plants. All seven EgACBPs were expressed in most tissues while their differential expression suggests various functions in specific tissues. For example, EgACBP3 had high expression in inflorescences and stalks while EgACBP1 showed strong expression in leaves. Because of the importance of E. guineensis as an oil crop, expression of EgACBPs was specifically examined during fruit development. EgACBP3 showed high expression throughout mesocarp development, while EgACBP1 had enhanced expression during rapid oil synthesis. In endosperm, both EgACBP1 and EgACBP3 exhibited increased expression during seed development. These results provide important information for further investigations on the biological functions of EgACBPs in various tissues and, in particular, their roles in oil synthesis.

Palm seed and fruit lipid composition: phylogenetic and ecological perspectives.

BACKGROUND AND AIMS: Palms are vital to worldwide human nutrition, in particular as major sources of vegetable oils. However, our knowledge of seed and fruit lipid diversity in the family Arecaceae is limited. We therefore aimed to explore relationships between seed and fruit lipid content, fatty acid composition in the respective tissues, phylogenetic factors and biogeographical parameters. METHODS: Oil content and fatty acid composition were characterized in seeds and fruits of 174 and 144 palm species respectively. Distribution, linear regression and multivariate analyses allowed an evaluation of the chemotaxonomic value of these traits and their potential relationship with ecological factors. KEY RESULTS: A considerable intra-family diversity for lipid traits was revealed. Species with the most lipid-rich seeds belonged to the tribe Cocoseae, while species accumulating oil in the mesocarp occurred in all subfamilies and two-thirds of the tribes studied. Seed and fruit lipid contents were not correlated. Fatty acid composition of mesocarp oil was highly variable within tribes. By contrast, within-tribe diversity for seed lipid traits was low, whereas between-tribe variability was high. Consequently, multivariate analyses of seed lipid traits produced groupings of species belonging to the same tribe. Medium-chain fatty acids predominated in seeds of most palm species, but they were also accumulated in the mesocarp in some cases. Seed unsaturated fatty acid content correlated with temperature at the coldest latitude of natural occurrence. CONCLUSION: Several previously uncharacterized palms were identified as potential new sources of vegetable oils for comestible or non-food use. Seed lipid traits reflect genetic drift that occurred during the radiation of the family and therefore are highly relevant to palm chemotaxonomy. Our data also suggest that seed unsaturated fatty acids may provide an adaptive advantage in the coldest environments colonized by palms by maintaining storage lipids in liquid form for efficient mobilization during germination.

Characterization and validation of olive FAD and SAD gene families: expression analysis in different tissues and during fruit development.

Stearoyl-ACP desaturases (SADs) and fatty acid desaturases (FADs) play a critical role in plant lipid metabolism and also affect oil fatty acid composition introducing double bonds into the hydrocarbon chains to produce unsaturated fatty acids. In the present study, the genomic sequences of three SAD and three FAD candidate genes were characterized in olive and their expression was evaluated in different plant tissues. OeSAD genes corresponded to olive SAD1 and SAD2 and to a newly identified OeSAD4, sharing the conserved protein structure with other plant species. On the other hand, the full-length genomic sequences of two microsomal OeFAD genes (FAD2-1 and FAD2-2) and the plastidial FAD6, were released. When the level of expression was tested on different tissues of cv. Leccino, OeSAD1 and OeSAD2 were mainly expressed in the fruits, while OeFAD genes showed the lowest expression in this tissue. The mRNA profiling of all genes was directly studied in fruits of Leccino and Coratina cultivars during fruit development. In both genotypes, the expression level of OeSAD1 and OeSAD2 had the highest value during and after the pit-hardening period, when oil accumulation in fruit mesocarp is intensively increasing. Furthermore, the expression level of both OeFAD2 genes, which were the main candidates for oleic acid desaturation, were almost negligible during fruit ripening. These results have made possible to define candidate genes of the machinery regulation of fatty acid composition in olive oil, providing information on their sequence, gene structure and chromosomal location.

Development of a low-cost electrochemical sensor based on babassu mesocarp (Orbignya phalerata) immobilized on a flexible gold electrode for applications in sensors for 5-fluorouracil chemotherapeutics.

There are increasing concerns regarding the risks arising from the contamination of manipulators of antineoplastic drugs promoted by occupational exposure or even in the dosage of drugs. The present work proposes the use of an electrochemical sensor based on a biopolymer extracted from the babassu coconut (Orbignya phalerata) for the determination of an antineoplastic 5-fluorouracil (5-FU) drug as an alternative for the monitoring of these drugs. In order to reduce the cost of this sensor, a flexible gold electrode (FEAu) is proposed. The surface modification of FEAu was performed with the deposition of a casting film of the biopolymer extracted from the babassu mesocarp (BM) and modified with phthalic anhydride (BMPA). The electrochemical activity of the modified electrode was characterized by cyclic voltammetry (CV), and its morphology was observed by atomic force microscopy (AFM). The FEAu/BMPA showed a high sensitivity (8.8 µA/µmol/L) and low limit of detection (0.34 µmol/L) for the 5-FU drug in an acid medium. Electrochemical sensors developed from the babassu mesocarp may be a viable alternative for the monitoring of the 5-FU antineoplastic in pharmaceutical formulations, because in addition to being sensitive to this drug, they are constructed of a natural polymer, renewable, and abundant in nature. Graphical abstract ᅟ.

Transcriptome Profiling Provides Insight into the Genes in Carotenoid Biosynthesis during the Mesocarp and Seed Developmental Stages of Avocado (Persea americana).

Avocado (Persea americana Mill.) is an economically important crop because of its high nutritional value. However, the absence of a sequenced avocado reference genome has hindered investigations of secondary metabolism. For next-generation high-throughput transcriptome sequencing, we obtained 365,615,152 and 348,623,402 clean reads as well as 109.13 and 104.10 Gb of sequencing data for avocado mesocarp and seed, respectively, during five developmental stages. High-quality reads were assembled into 100,837 unigenes with an average length of 847.40 bp (N50 = 1725 bp). Additionally, 16,903 differentially expressed genes (DEGs) were detected, 17 of which were related to carotenoid biosynthesis. The expression levels of most of these 17 DEGs were higher in the mesocarp than in the seed during five developmental stages. In this study, the avocado mesocarp and seed transcriptome were also sequenced using single-molecule long-read sequencing to acquired 25.79 and 17.67 Gb clean data, respectively. We identified 233,014 and 238,219 consensus isoforms in avocado mesocarp and seed, respectively. Furthermore, 104 and 59 isoforms were found to correspond to the putative 11 carotenoid biosynthetic-related genes in the avocado mesocarp and seed, respectively. The isoform numbers of 10 out of the putative 11 genes involved in the carotenoid biosynthetic pathway were higher in the mesocarp than those in the seed. Besides, alpha- and beta-carotene contents in the avocado mesocarp and seed during five developmental stages were also measured, and they were higher in the mesocarp than in the seed, which validated the results of transcriptome profiling. Gene expression changes and the associated variations in gene dosage could influence carotenoid biosynthesis. These results will help to further elucidate carotenoid biosynthesis in avocado.

WRI1-1, ABI5, NF-YA3 and NF-YC2 increase oil biosynthesis in coordination with hormonal signaling during fruit development in oil palm.

The oil biosynthesis pathway must be tightly controlled to maximize oil yield. Oil palm accumulates exceptionally high oil content in its mesocarp, suggesting the existence of a unique fruit-specific fatty acid metabolism transcriptional network. We report the complex fruit-specific network of transcription factors responsible for modulation of oil biosynthesis genes in oil palm mesocarp. Transcriptional activation of EgWRI1-1 encoding a key master regulator that activates expression of oil biosynthesis genes, is activated by three ABA-responsive transcription factors, EgNF-YA3, EgNF-YC2 and EgABI5. Overexpression of EgWRI1-1 and its activators in Arabidopsis accelerated flowering, increased seed size and oil content, and altered expression levels of oil biosynthesis genes. Protein-protein interaction experiments demonstrated that EgNF-YA3 interacts directly with EgWRI1-1, forming a transcription complex with EgNF-YC2 and EgABI5 to modulate transcription of oil biosynthesis pathway genes. Furthermore, EgABI5 acts downstream of EgWRKY40, a repressor that interacts with EgWRKY2 to inhibit the transcription of oil biosynthesis genes. We showed that expression of these activators and repressors in oil biosynthesis can be induced by phytohormones coordinating fruit development in oil palm. We propose a model highlighting a hormone signaling network coordinating fruit development and fatty acid biosynthesis.

Phytosterol Composition of Arachis hypogaea Seeds from Different Maturity Classes.

The seeds of cultivated peanut, Arachis hypogaea, are an agronomically important crop produced for human nutrition, oilseed and feed stock. Peanut seed is the single most expensive variable input cost and thus producers require seed with excellent performance in terms of germination efficiency. During the maturation process, triglycerides are stored in oil bodies as an energy resource during germination and seedling development. The stability of oil body membranes is essential for nutrient mobilization during germination. This study focused on evaluating the phytosterol composition in seed components including the kernel, embryo (heart), and seed coat or skin. Samples of different maturity classes were analyzed for macronutrient and phytosterol content. The three biosynthetic end products in the phytosterol pathway, ß-sitosterol, campesterol and stigmasterol, comprised 82.29%, 86.39% and 94.25% of seed hearts, kernels and seed coats, respectively. Stigmasterol concentration was highest in the seed kernel, providing an excellent source of this sterol known to have beneficial effects on human health. Peanut hearts contained the highest concentration of sterols by mass, potentially providing protection and resources for the developing seedling. The amount of α-tocopherol increases in peanut hearts during the maturation process, providing protection from temperature stress, as well as stability required for seedling vigor. These results suggest that phytosterols may play a significant role in the performance of seeds, and provide a possible explanation for the poor germination efficiency of immature seeds.

Subcritical Water-Carbon Dioxide Pretreatment of Oil Palm Mesocarp Fiber for Xylooligosaccharide and Glucose Production.

The present work aimed to investigate the pretreatment of oil palm mesocarp fiber (OPMF) in subcritical H2O-CO2 at a temperature range from 150⁻200 °C and 20⁻180 min with CO2 pressure from 3⁻5 MPa. The pretreated solids and liquids from this process were separated by filtration and characterized. Xylooligosaccharides (XOs), sugar monomers, acids, furans and phenols in the pretreated liquids were analyzed by using HPLC. XOs with a degree of polymerization X2⁻X4 comprising xylobiose, xylotriose, xylotetraose were analyzed by using HPAEC-PAD. Enzymatic hydrolysis was performed on cellulose-rich pretreated solids to observe xylose and glucose production. An optimal condition for XOs production was achieved at 180 °C, 60 min, 3 MPa and the highest XOs obtained was 81.60 mg/g which corresponded to 36.59% of XOs yield from total xylan of OPMF. The highest xylose and glucose yields obtained from pretreated solids were 29.96% and 84.65%, respectively at cellulase loading of 10 FPU/g-substrate.

Evaluating oil palm fresh fruit bunch processing in Nigeria.

Three routes of oil palm fresh fruit bunch (FFB) processing in Nigeria namely, industrial, small-scale and traditional were compared by means of determining fruit losses associated with each route. The fruits that are not recovered after each process were hand-picked and quantified in terms of crude palm oil (CPO), palm kernel (PK), mesocarp fibre (MF) and palm kernel shell (PKS). The energy value of empty fruit bunch (EFB), MF and PKS were used to determine the value of energy lost for each route. Additionally, the environmental implications of disposal of EFB were estimated, and socio-economics of the industrial and small-scale routes were related. The analysis showed that 29, 18, 75 and 27 kg of CPO, PK, MF and PKS were lost for every 1000 kg of FFB processed with the industrial route, whereas 5.6, 3.2, 1.4 and 5.1 g were lost with the small-scale route, respectively. Approximately 89 kWh and 31 kWh more energy were lost from MF and PKS with the industrial route than the other two routes, respectively. An equivalent of 6670 tonnes carbon dioxide equivalent of methane and nitrogen oxide was released due to the disposal of 29,000 tonnes of EFB from one palm oil mill. The monetary value of lost CPO per 1000 kg of FFB processed in the industrial route is more than the labour cost of processing 1000 kg of FFB in the small-scale route. The advantages of the industrial route are high throughput in terms of FFB processed per hour and high quality of CPO; however, high fruit loss is associated with it and therefore, the poorly threshed EFB is recommended to be fed into the small-scale route.

Irrigation and fruit canopy position modify oil quality of olive trees (cv. Frantoio).

BACKGROUND: Fruit development and oil quality in Olea europaea L. are strongly influenced by both light and water availability. In the present study, the simultaneous effects of light environment and irrigation on fruit characteristics and oil quality were studied in a high-density orchard over two consecutive years. Olive fruits were harvested from three canopy positions (intercepting approximately 64%, 42% and 30% of above canopy radiation) of fully-productive trees subjected to full, deficit or complementary irrigation. RESULTS: Fruits receiving 61-67% of above canopy radiation showed the highest fruit weight, mesocarp oil content and maturation index, whereas those intercepting only 27-33% showed the lowest values. Palmitoleic and linoleic acids increased in oils obtained from fruits exposed to high light levels, whereas oleic acid and the oleic-linoleic acid ratio decreased. Neither canopy position, nor irrigation affected K232 , K270 , ΔK and the concentration of lignan in virgin olive oils (VOOs). Total phenols, 3,4-DHPEA-EDA [2-(3,4-hydroxyphenyl)ethyl (3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate] and p-HPEA-EDA (decarboxymethyl ligstroside-aglycone) increased in VOOs produced from fruits harvested from the top of the canopy, whereas full irrigation decreased total phenols and 3,4-DHPEA-EDA concentrations with respect to the complementary irrigation treatment. CONCLUSION: Light and water availability are crucial not only for tree productivity, but also they clearly affect olive oil quality. © 2017 Society of Chemical Industry.

Proteomic analysis of pear (Pyrus pyrifolia) ripening process provides new evidence for the sugar/acid metabolism difference between core and mesocarp.

Pears are one of the most popular nutrient-rich fruits in the world. The pear core and mesocarp have significantly different metabolism, although they display similar profiles. Most strikingly, the core is more acidic in taste. Our results showed that there is more titrated acid but lower total soluble solids in the core compared to the mesocarp, and the content of citric acid was more than 17-fold higher in the core compared to the mesocarp at the ripening stage. Proteomics was used to investigate the difference between core and mesocarp tissues during "Cuiguan" pear ripening. Fifty-four different protein expression patterns were identified in the core and mesocarp. In general, common variably expressed proteins between the core and mesocarp were associated with important physiological processes, such as glycolysis, pyruvate metabolic processes, and oxidative stress. Further, protein level associated qRT-PCR verification revealed a higher abundance of fructose-bisphosphate aldolase and NADP-dependent malic enzymes, which may play a role in the low acid content in the mesocarp, whereas a higher abundance of disulfide isomerase-like 2-2 and calcium-dependent lipid-binding in the core may explain why it is less prone to accumulate sugar. The different levels of a few typical ROS scavenger enzymes suggested that oxidative stress is higher in the core than in the mesocarp. This study provides the first characterization of the pear core proteome and a description of its variation compared to the mesocarp during ripening.

The peach HECATE3-like gene FLESHY plays a double role during fruit development.

Tight control of cell/tissue identity is essential for a correct and functional organ patterning, an important component of overall fruit development and eventual maturation and ripening. Despite many investigations regarding the molecular determinants of cell identity in fruits of different species, a useful model able to depict the regulatory networks governing this relevant part of fruit development is still missing. Here we described the peach fruit as a system to link the phenotype of a slow ripening (SR) selection to an altered transcriptional regulation of genes involved in determination of mesocarp cell identity providing insight toward molecular regulation of fruit tissue formation. Morpho-anatomical observations and metabolomics analyses performed during fruit development on the reference cultivar Fantasia, compared to SR, revealed that the mesocarp of SR maintained typical immaturity traits (e.g. small cell size, high amino acid contents and reduced sucrose) throughout development, along with a strong alteration of phenylpropanoid contents, resulting in accumulation of phenylalanine and lignin. These findings suggest that the SR mesocarp is phenotypically similar to a lignifying endocarp. To test this hypothesis, the expression of genes putatively involved in determination of drupe tissues identity was assessed. Among these, the peach HEC3-like gene FLESHY showed a strongly altered expression profile consistent with pit hardening and fruit ripening, generated at a post-transcriptional level. A double function for FLESHY in channelling the phenylpropanoid pathway to either lignin or flavour/aroma is suggested, along with its possible role in triggering auxin-ethylene cross talk at the start of ripening.

PpAmy1 Plays a Role in Fruit-Cracking by Regulating Mesocarp Starch Hydrolysis of Nectarines.

Nectarine [Prunus persica (L.) Batsch var.] fruits are highly susceptible to cracking during the ripening process, which significantly decreases their commercial value. In this study, we investigated the underlying mechanism of nectarine fruit-cracking using two nectarine varieties, namely, "Qiannianhong" (cracking-susceptible) and "CR1012" (cracking-resistant). Our findings indicate that nectarine fruit-cracking occurs during the second stage of fruit expansion. Despite no differences in epicarp cell size between "Qiannianhong" and "CR1012", the mesocarp cells of "Qiannianhong" were larger than those of "CR1012". Moreover, a comparison of starch hydrolysis between the two varieties revealed that "CR1012" had higher starch content in the mesocarp but lower soluble sugar content compared to "Qiannianhong". Additionally, by testing the α-amylase and ß-amylase activity of the mesocarp, our results showed a difference only in α-amylase activity between the two varieties. Furthermore, qRT-PCR detection indicated a higher expression level of the PpAmy1 (α-amylase synthesis gene) in "Qiannianhong" compared to "CR1012". To further investigate the role of PpAmy1, we employed RNAi technology to suppress its expression in "Qiannianhong" fruits. The results showed a significant reduction in α-amylase activity, starch hydrolysis, soluble sugar content, cell size of the mesocarp, and fruit-cracking. These findings underscore the pivotal role of PpAmy1 in the occurrence of nectarine fruit cracking.

Insulin Sensitivity of Adipocytes is Improved by Pomegranate Mesocarp Through Reduced Oxidative Stress and Inflammation.

OBJECTIVE: Inflammatory phenomena and increase in oxidative stress in cell physiopathology progression render therapeutic strategies based on nutritional antioxidants necessary. It was thus aimed at assessing the effectiveness of the pomegranate mesocarp extract (PME) on differentiation of preadipocytes to adipocytes in the presence/absence of hydrogen peroxide (H2O2), a model mimicking insulin resistance. METHOD: The effect of PME on lipid accumulation, protein expression of antioxidant, inflammatory and adipogenic biomarkers, reactive oxygen species production, activity of antioxidant enzymes and secretion of IL-6 has been evaluated during the differentiation of preadipocytes to adipocytes, in the presence or absence of H2O2. RESULTS: H2O2 reduced the expression of the regulator of insulin sensitivity PPARγ and suppressed adipocyte differentiation. PME counteracted the effect of H2O2. The latter induced a higher level of fat accumulation by promoting the expressions of the adipogenic markers PPARγ, C/EBPα, FABP4 and CD36 as compared to the control and the H2O2-treated differentiating cells. During the progression of adipogenesis, highest increase (p < 0.05) in IL-6 secretion, by 3.16 and 3.85 folds, was observed on day 2 of differentiation in control and H2O2-treated cells, respectively, compared to day 0. PME significantly decreased (p < 0.01) the secretion of the cytokine in addition to suppressing the expression of NFκB. PME also prevented the reduction of superoxide dismutase, catalase and glutathione peroxidase activities that occurred during adipogenesis, by at most 33%, 119% and 42%, respectively. CONCLUSION: These findings indicate that PME efficiently improves insulin sensitivity and can significantly counteract oxidative stress and inflammation.

Unusual vitamin E profile in the oil of a wild African oil palm tree (Elaeis guineensis Jacq.) enhances oxidative stability of provitamin A.

Introduction: The African oil palm (Elaeis guineensis Jacq.) is the predominant oil crop in the world. In addition to triacylglycerols, crude palm oil (CPO) extracted from the mesocarp of the fruits, contains high amounts of provitamin A (carotenes) and vitamin E (tocochromanols). Because of their unsaturated nature, the carotenes are prone to oxidation and therefore are in part limiting for the shelf life of CPO. Methods: A tree with unusual toochromanol composition was identified by HPLC screening of the mesocarp of wild trees. Polymorphisms in a candidate gene were identified by DNA sequencing. The candidate protein was heterologously expressed in Escherichia coli coli and Arabidopsis thaliana to test for enzyme activity. Oxidative stability of the CPO was studied by following carotene degradation over time. Results: In the present study, a wild Oil Palm tree (C59) from Cameroon was identified that lacks α-tocopherol and α-tocotrienol and instead accumulates the respective γ forms, suggesting that the activity of γ-tocopherol methyltransferase (VTE4) was affected. Sequencing of the VTE4 locus in the genome of plant C59 identified a G/C polymorphism that causes the exchange of a highly conserved tryptophan at position 290 with serine. The W290S exchange renders the VTE4 enzyme inactive, as shown after expression in Escherichia coli and Arabidopsis thaliana. The oxidative stability of carotenes in the mesocarp of the wild palm C59 was enhanced compared with control accessions. Furthermore, supplementation of commercial palm oil with different tocochromanols showed that γ-tocotrienol exerts a stronger effect during the protection of carotenes against oxidation than α-tocotrienol. Discussion: Therefore, the introduction of the high γ-tocotrienol trait into elite breeding lines represents a potent strategy to protect carotenes against oxidation and extend the shelf life of CPO, hence allowing the development of a value added high-carotene CPO to be used to fight against vitamin A deficiency.