Grape is one of the oldest fruit crops domesticated by humans. The numerous uses of grape in making wine, beverages, jelly, and other products, has made it one of the most economically important ...plants worldwide. The complex phytochemistry of the berry is characterized by a wide variety of compounds, most of which have been demonstrated to have therapeutic or health promoting properties. Among them, flavonoids are the most abundant and widely studied, and have enjoyed greater attention among grape researchers in the last century. Recent studies have shown that the beneficial health effects promoted by consumption of grape and grape products are attributed to the unique mix of polyphenolic compounds. As the largest group of grape polyphenols, flavonoids are the main candidates considered to have biological properties, including but not limited to antioxidant, anti-inflammatory, anti-cancer, antimicrobial, antiviral, cardioprotective, neuroprotective, and hepatoprotective activities. Here, we discuss the recent scientific advances supporting the beneficial health qualities of grape and grape-derived products, mechanisms of their biological activity, bioavailability, and their uses as nutraceuticals. The advantages of modern plant cell based biotechnology as an alternative method for production of grape nutraceuticals and improvement of their health qualities are also discussed.
Essential oils and hydrosols of two cultivars of muscadine grapes (
(Michx.) Small.) were obtained by hydro-distillation of flowers and berry skins. Twenty-three volatile compounds were identified in ...essential oils from the muscadine flowers, and twenty volatiles in their corresponding hydrosols. The composition of volatiles in berry skins differed significantly from that of the vine flowers. The antioxidant potential of investigated essential oils and hydrosols was evaluated using five in vitro assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) method, TEAC (Trolox equivalent antioxidant capacity), FRAP (Ferric reducing antioxidant power), CUPRAC (cupric ion reducing antioxidant capacity), and NO (nitric oxide radical scavenging assay). The essential oils from the flowers of both cultivars showed the strongest antioxidant power, whereas the hydrosols were the significantly less active. All investigated essential oils showed very weak antibacterial activities against
,
,
, and
. However, the essential oils from the flowers of both cultivars showed moderate antifungal activities against
, which were stronger for the oil from "Carlos" (white muscadine cultivar). To the best of our knowledge, this is the first report on obtaining and characterizing essential oils and hydrosols from muscadine grapes. This study demonstrated the variations in aromatic compounds accumulated in flowers and mature berry skins of muscadine grapes, and evaluated their possible antioxidant and antimicrobial activities. The presented results will be the base for future research, focused on a better understanding of the molecular and regulatory mechanisms involved in aromatic compound biosynthesis and accumulation in muscadine grapes.
Polyphenols are bioactive natural molecules biogenerated through secondary metabolic pathways. They are involved in different functions in the ecology, physiology, and biochemistry of plants such as ...chemical defense against predators and in plant-plant interferences. These compounds are known to have important biological activities related to human health such as antioxidant action, antiinflammatory and antimicrobial effects. The immense health benefits as well as use of many polyphenolic compounds as anti-infective agents against human pathogens have heightened the need for continuous supply of rare and expensive secondary metabolites. It has been demonstrated that the chemical structure of dietary polyphenols, such as the number and position of hydroxyl groups, can change their biological properties and bioavailability. This review focuses on prospects for, and success in metabolic engineering, including manipulation of structural regulatory genes to develop plants with tailor-made, optimized levels and composition of polyphenols.
Fruit allergens are proteins from fruits or pollen that cause allergy in humans, an increasing food safety concern worldwide. With the globalization of food trade and changing lifestyles and dietary ...habits, characterization and identification of these allergens are urgently needed to inform public awareness, diagnosis and treatment of allergies, drug design, as well as food standards and regulations. This study conducted a phylogenetic reconstruction and protein clustering among 60 fruit and pollen allergens from 19 species, and analyzed the clusters, in silico, for cross-reactivity (IgE), 3D protein structure prediction, transmembrane and signal peptides, and conserved domains and motifs. Herein, we wanted to predict the likelihood of their interaction with antibodies, as well as cross-reactivity between the many allergens derived from the same protein families, as the potential for cross-reactivity complicates the management of fruit allergies. Phylogenetic analysis classified the allergens into four clusters. The first cluster (n = 9) comprising pollen allergens showed a high risk of cross-reactivity between eight allergens, with Bet v1 conserved domain, but lacked a transmembrane helix and signal peptide. The second (n = 10) cluster similarly suggested a high risk of cross-reactivity among allergens, with Prolifin conserved domain. However, the group lacked a transmembrane helix and signal peptide. The third (n = 13) and fourth (n = 29) clusters comprised allergens with significant sequence diversity, predicted low risk of cross-reactivity, and showed both a transmembrane helix and signal peptide. These results are critical for treatment and drug design that mostly use transmembrane proteins as targets. The prediction of high risk of cross-reactivity indicates that it may be possible to design a generic drug that will be effective against the wide range of allergens. Therefore, in the past, we may have avoided the array of fruit species if one was allergic to any one member of the cluster.
Cassava plays an important role in the life and diet of several communities worldwide. It is used in various processed forms and has become the focus of research and innovation in recent years. ...Bioprocessing techniques, such as fermentation, have been utilized to create new avenues for its application in food and functional products. The fermentation of cassava can enhance its nutritional value, improve its shelf life, and increase its digestibility. However, the effect of salt-mediated fermentation on microbial diversity and potential benefits has not been widely reported. In this study, the effect of six levels of salt (NaCl), ranging from 0 to 25% after 50 days of spontaneous cassava fermentation at 25–30 °C, was investigated. A total of 30 bacterial isolates were selected for molecular characterization. A proprietary pool of universal 16S rRNA primers and species-specific primers were used to amplify a wide variety of species in clonal samples. The bacteria observed include Lactiplantibacillus, Limosilactobacillus, and Weissella. The population of Lactiplantibacillus in the cassava microflora increased with and without salt treatment, while Weissella, a new genus, was detected in 20 and 25% of salt-treated samples. Lactiplantibacillus and Weissella accounted for 32 and 68% and 60 and 40% of the bacterial populations detected at 20 and 25% salt treatment, respectively. A total of 17 strains and sequences were identified from the 30 isolates screened. Sequencing results classified the 30 isolates into four groups, of which 76.67% were Limosilactobacillus. Phylogenetic analysis showed that all 17 strains were divided into three clusters. These results show that high salt-mediated fermentation of cassava can trigger a shift in dominance in the bacterial community, changing the diversity of the microbial community.
The small hive beetle (Aethina tumida Murray) is a serious threat to beekeeping and crops that rely on honeybees for pollination. The small hive beetle not only causes significant damage to honeybees ...by feeding on pollen and honey, attacking bee brood and causing stored honey to ferment, but also might serve as a vector of diseases. In addition, the small hive beetle has developed resistance to the pyrethroid and organophosphate insecticides registered for control of honeybee pests in the United States. The development of resistance in small hive beetle populations is a great concern to the beekeeping industry; thus, there is an urgent need for strategies to manage that resistance. Therefore, we used synergist probes to determine the mechanisms of resistance in a small hive beetle population to these insecticides. Our studies on the toxicity of insecticides alone or with the synergists piperonyl butoxide (PBO) and S,S,S,-tributyl phosphorotrithionate (DEF) suggested that mixed-function oxidases and esterases were the major resistance factors to these insecticides in a studied population of the small hive beetle. In contrast, there was no synergism with diethyl maleate (DEM), triphenyl phosphate (TPP) and formamidine. Therefore, glutathione-S-transferase, carboxylesterase and target site were not involved in insecticide resistance in the small hive beetle. Rotation of classes of insecticides (with different modes of action) and metabolic synergists were suggested for the development of successful resistance management programs. To the best of our knowledge, this is the first study of the mechanisms of resistance in small hive beetle populations in Florida and suggests an urgent need for alternative control strategies for these serious pests of honeybee colonies.
Salinity is one of the most destructive environmental challenges for citriculture worldwide, and all climate change scenarios are predicting an increased impact of salinity on citrus orchards. Citrus ...cultivars are grown as grafts on various rootstocks to provide specific adaptation to abiotic stress and tolerance to major diseases such as citrus tristeza virus. To understand rootstock–scion interactions with regard to salinity, transcriptome profiling of mRNA expression was analyzed for 12 candidate genes in leaves, shoots, and roots of five Hernandina clementine scions grafted on Rangpur lime (LR), Volkamer lemon (CV), Carrizo citrange (CC), sour orange (Big), and Cleopatra mandarin (MC) rootstocks in response to moderate and severe salinity. qRT-PCR analysis revealed differential gene expression that varied by rootstock, salinity level, and tissue. The majority of induced genes were those involved in ion transporter proteins (mainly NHX1 and HKT1 genes), Cl− homeostasis (CCC1 gene), biosynthesis and accumulation of compatible osmolytes, proline (P5CS gene) and glycine betaine (CMO gene), accumulation of proteins (LEA2 gene), and ROS scavenging antioxidant activity (mainly APX). We show that these expression patterns could explain the relative tolerance of the used rootstocks and report new insights on the main salt tolerance mechanisms activated by these rootstocks.
The croton scale Phalacrococcus howertoni Hodges & Hodgson gen. nov., sp. nov. (Hemiptera: Coccidae), was first found in Florida, USA. This scale has become a pest because of its high reproductive ...rate and production of sooty mold. Here, we evaluated predation potential of the predatory beetle, Thalassa montezumae Mulsant (Coleoptera: Coccinellidae), as a biological control agent. To our knowledge, this is the first study of predation by T. montezumae on P. howertoni. Results of our studies showed that the predation by 4th instar T. montezumae was higher on 2nd stage nymphs than on 3rd stage nymphs P. howertoni; predation on adults was lowest. Mean consumption by adult T. montezumae was highest on 2nd stage nymphs followed by 3rd stage nymphs, and adult P. howertoni. There were no significant differences between male and female adult T. montezumae in the prey first visited when offered a choice of 2nd or 3rd instar nymphs, or adults of P. howertoni. Thus, the levels of acceptance did not vary significantly between stages of prey visited by the males and females. Females chose prey faster than males and used less energy to search for food. Egg fecundity did not vary among female beetles fed with different stages of croton scales. Should P. howertoni become a major pest, T. montezumae could be used as a biological control agent within a biologically based integrated pest management program.
The skin color of grape berry is very important in the wine industry. The red color results from the synthesis and accumulation of anthocyanins, which is regulated by transcription factors belonging ...to the MYB family. The transcription factors that activate the anthocyanin biosynthetic genes have been isolated in model plants. However, the genetic basis of color variation is species-specific and its understanding is relevant in many crop species. This study reports the isolation of
, and
genes from muscadine grapes for the first time. They are designated as
(GenBank Accession No. KJ513437), and
(
) (GenBank Accession No. KJ513438). The findings in this study indicate that, the deduced
and
protein structures share extensive sequence similarity with previously characterized plant MYBs, while phylogenetic analysis confirms that they are members of the plant MYB super-family. The expressions of
, and
(
) gene sequences were investigated by quantitative real-time PCR using in vitro cell cultures, and berry skin samples at different developmental stages. Results showed that
, and
genes were up-regulated in the veràison and physiologically mature red berry skins during fruit development, as well as in in vitro red cell cultures. This study also found that in ripening berries, the transcription of
, and
in the berry skin was positively correlated with anthocyanin accumulation. Therefore, the upregulation of
, and
results in the accumulation and regulation of anthocyanin biosynthesis in berry development of muscadine grapes. This work greatly enhances the understanding of anthocyanin biosynthesis in muscadine grapes and will facilitate future genetic modification of the antioxidants in
.
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