Isolation and Functional Characterization of a LEAFY Gene in Mango (Mangifera indica L.).

LEAFY (LFY) plays an important role in the flowering process of plants, controlling flowering time and mediating floral meristem differentiation. Owing to its considerable importance, the mango LFY gene (MiLFY; GenBank accession no. HQ585988) was isolated, and its expression pattern and function were characterized in the present study. The cDNA sequence of MiLFY was 1152 bp, and it encoded a 383 amino acid protein. MiLFY was expressed in all tested tissues and was highly expressed in flowers and buds. Temporal expression analysis showed that MiLFY expression was correlated with floral development stage, and two relative expression peaks were detected in the early stages of floral transition and floral organ differentiation. Moreover, 35S::GFP-MiLFY fusion protein was shown to be localized to the nucleus of cells. Overexpression of MiLFY in Arabidopsis promoted early flowering and the conversion of lateral meristems into terminal flowers. In addition, transgenic plants exhibited obvious morphological changes, such as differences in cauline leaf shape, and the number of lateral branches. When driven by the MiLFY promoter, GFP was highly expressed in leaves, floral organs, stems, and roots, during the flowering period. Exogenous gibberellin (GA3) treatment downregulated MiLFY promoter expression, but paclobutrazol (PPP333) upregulated it. Bimolecular fluorescence complementation (BiFC) assays showed that the MiLFY protein can interact with zinc-finger protein 4 (ZFP4) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (MiSOC1D). Taken together, these results indicate that MiLFY plays a pivotal role in controlling mango flowering, and that it is regulated by gibberellin and paclobutrazol.

Phenolic compounds profile and antioxidant capacity of 'Ataulfo' mango pulp processed by ohmic heating at moderate electric field strength.

Heat treatment during pasteurization of mango (Mangifera indica L.) pulp reduces the phenolic content and its potential health benefits. The bioactive content, phenolics profile, and antioxidant capacity of 'Ataulfo' mango pulp after ohmic heating (OH) treatment (15.0-20.0 V/cm), and conventional heating (CT, 72 °C) were evaluated. No significant differences were observed in the gallic acid and mangiferin content and its antioxidant capacity (ABTS). Mass spectrometry analysis (LC/MS-TOF) showed that all treatments produced the same profile of phenolic compounds, including 6 phenolic acids, 2 gallotannins, 1 benzophenone, 2 xanthones, and 3 flavonoids. PCA analysis confirmed that mangiferin and gallic acid were the main contributors to the ABTS antioxidant capacity. These results demonstrate that OH treatments can preserve the compositions of phenolic compounds mango pulp, thus maintaining its potential health benefits.

Integrated Metabolome and Transcriptome Analysis of Fruit Flavor and Carotenoids Biosynthesis Differences Between Mature-Green and Tree-Ripe of cv. "Golden Phoenix" Mangoes (Mangifera indica L.).

The commodity value of fruits is directly affected by fruit flavor and color. Secondary metabolites, such as amino acids, organic acids, esters, and ß-carotene, are important synthetic products, which are of great significance in the flavor formation of mango fruits. In this study, a total of 309 different metabolites, consisting of organic acids, amino acids, phenolic acids, and saccharides, and a further 84 types of volatile organic compounds (VOCs) were identified in differential levels in TR vs. MG mango fruit stages. The major volatile compounds found were ester [2(3H)-furanone, 5-ethyldihydro; N-(2,5-ditrifluoromethylbenzoyl)-D-alanine, pentyl ester; and Octanoic acid, ethyl ester], aldehyde (benzaldehyde, 3-ethyl, and nonanal), and phenol [2-(1,1-dimethylethyl)-6-(1-methylethyl) phenol]. The analysis of carotenoid contents identified 68 carotenoids and we report for the first-time significant contents of zeaxanthin palmitate and (E/Z)-phytoene in mango fruits. α-carotene was a further major contributor to carotene contents with lesser contributions from 5,6epoxy-lutein-caprate-palmitate, ß-carotene, lutein oleate, and ß-cryptoxanthin. What is more, lutein content was significantly decreased in TR vs. MG fruit. RT-qPCR analysis revealed that relative to the MG stage, the expression of carotenogenic genes GGPS, PSY, LCYB, and ZEP was downregulated in TR mango fruit, whereas the transcript levels of PSD, CHYB, and NCED were downregulated. Additionally, the transcription level of some transcription factors (MYB, bHLH, and NAC) was highly correlated with pigment content in the pulp and may be responsible for carotenoid accumulation. The results describe major differences in metabolic pathways during the transition from MG to the TR stage of fruit ripening that are likely to contribute alterations in fruit flavor and provide several associated genes to be further studied in mango fruit.

Kinetic, Thermodynamic, Physicochemical, and Economical Characterization of Pectin from Mangifera indica L. cv. Haden Residues.

The effect of temperature (60, 70, 80, and 90 °C) and time (30, 45, 60, 75, and 90 min) on citric acid extraction of Haden mango (Mangifera indica L. cv. Haden) peel pectin was evaluated in the present study. In order to obtain a better understanding of both the extraction process and the characteristics of the pectin (obtained from an agro-industrial waste) for a future scaling process, the following characterizations were performed: (1) Kinetic, with the maximum extraction times and yields at all evaluated temperatures; (2) thermodynamic, obtaining activation energies, enthalpies, entropies, and Gibbs free energies for each stage of the process; (3) physicochemical (chemical analysis, monosaccharide composition, degree of esterification, galacturonic acid content, free acidity, Fourier-transform infrared spectroscopy, thermogravimetric and derivative thermogravimetric analyses); and (4) economical, of the pectin with the highest yield. The Haden mango peel pectin was found to be characterized by a high-esterified degree (81.81 ± 0.00%), regular galacturonic acid content (71.57 ± 1.26%), low protein (0.83 ± 0.05%) and high ash (3.53 ± 0.02%) content, low mean viscometric molecular weight (55.91 kDa), and high equivalent weight (3657.55 ± 8.41), which makes it potentially useful for food applications.

Influence of extrusion process on the release of phenolic compounds from mango (Mangifera indica L.) bagasse-added confections and evaluation of their bioaccessibility, intestinal permeability, and antioxidant capacity.

Extruded polyphenol-rich by-products like mango bagasse (MB) could be used to manufacture functional confections. However, few reports have assessed the extrusion impact on MB polyphenols within a food matrix. This research aimed to evaluate the impact of extrusion on the bioaccessibility, intestinal permeability, and antioxidant capacity of phenolic compounds (PC) from non-extruded and extruded MB-added confections (EMBC and MBC, respectively). The inhibition of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radicals and in silico approaches were used to evaluate the antioxidant capacity. MBC displayed the highest gastric bioaccessibility (%) of xanthones and flavonoids, whereas selective release of gallic acid, mangiferin, and quercetin glucoside was shown for EMBC. Lower PC' apparent permeability coefficients were found in EMBC compared to MB (0.11 to 0.44-fold change, p < 0.05). EMBC displayed the highest antioxidant capacity by the DPPH method for the non-digestible fraction, being mangiferin the highest in silico contributor (-4 kcal/mol). Our results showed that the extrusion process helps release selective phenolics from MBC, which increases their bioaccessibility and intestinal permeability.

Gastrointestinal metabolism of monomeric and polymeric polyphenols from mango (Mangifera indica L.) bagasse under simulated conditions.

Mango bagasse (MB) is an agro-industrial by-product rich in bioactive polyphenols with potential application as a functional ingredient. This study aimed to delineate the metabolic fate of monomeric/polymeric MB polyphenols subjected to simulated gastrointestinal digestion. The main identified compounds by LC/MS-TOF-ESI were phenolic acids [gallic acid (GA) and derivates, and chlorogenic acid], gallotannins and derivatives [di-GA (DA) and 3GG-to-8GG], benzophenones [galloylated maclurins (MGH, MDH)], flavonoids [Quercetin (Quer) and (QuerH)] and xanthones [mangiferin isomers]. The bioaccessibility depended on the polyphenols' structure, being Quer, 5G to 8G the main drivers. The results suggested that the gastrointestinal fate of MB polyphenols is mainly governed by benzophenones and gallotannins degalloylation and spontaneous xanthone isomerization in vitro to sustain GA bioaccessibility.

Characterization of Two Ethephon-Induced IDA-Like Genes from Mango, and Elucidation of Their Involvement in Regulating Organ Abscission.

In mango (Mangifera indica L.), fruitlet abscission limits productivity. The INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide acts as a key component controlling abscission events in Arabidopsis. IDA-like peptides may assume similar roles in fruit trees. In this study, we isolated two mango IDA-like encoding-genes, MiIDA1 and MiIDA2. We used mango fruitlet-bearing explants and fruitlet-bearing trees, in which fruitlets abscission was induced using ethephon. We monitored the expression profiles of the two MiIDA-like genes in control and treated fruitlet abscission zones (AZs). In both systems, qRT-PCR showed that, within 24 h, both MiIDA-like genes were induced by ethephon, and that changes in their expression profiles were associated with upregulation of different ethylene signaling-related and cell-wall modifying genes. Furthermore, ectopic expression of both genes in Arabidopsis promoted floral-organ abscission, and was accompanied by an early increase in the cytosolic pH of floral AZ cells-a phenomenon known to be linked with abscission, and by activation of cell separation in vestigial AZs. Finally, overexpression of both genes in an Atida mutant restored its abscission ability. Our results suggest roles for MiIDA1 and MiIDA2 in affecting mango fruitlet abscission. Based on our results, we propose new possible modes of action for IDA-like proteins in regulating organ abscission.

Bioconversion by gut microbiota of predigested mango (Mangifera indica L) 'Ataulfo' peel polyphenols assessed in a dynamic (TIM-2) in vitro model of the human colon.

Gut microbiota bioconversion of polyphenols in predigested mango 'Ataulfo' peel was studied using a validated, dynamic in vitro human colon model (TIM-2) with faecal microbial inoculum. Dried peels were predigested with enzymatic treatment, followed by TIM-2 fermentation (72 h). Samples were taken at 0, 24, 48 and 72 h and analyzed by HPLC-QToF. Derivatives of hydroxyphenylpropionic, hydroxyphenylacetic and hydroxybenzoic acids, as well as, pyrogallol were the main polyphenols identified. These metabolites might derivate from flavonoid (flavanols and flavonols), gallate and gallotannin biotransformation. Despite the high content of ellagic acid in mango peel, low amounts were detected in TIM-2 samples due to transformation into urolythins A and C, mainly. Xanthone and benzophenone derivatives, specific to mango, remained after the colonic biotransformation, contrary to flavonoids, which completely disappeared. In conclusion, microbial-derived metabolites, such as xanthone and benzophenone derivatives, among others, are partially stable after colonic fermentation, and thus have the potential to contribute to mango peel bioactivity.

The impact of ventilation during postharvest ripening on the development of flavour compounds and sensory quality of mangoes (Mangifera indica L.) cv. Kent.

The postharvest ripening behaviour of mangoes (Mangifera indica L.) and particularly the development of colour, volatiles, sensory properties and texture, were investigated. Mangoes cv. Kent from Peru were arranged in a postharvest ripening chamber in two different ways enabling different ventilation of the fruits. Fruit properties were investigated in comparison to reference fruits after postharvest ripening for 78 h. Volatile compounds were analysed by HS-SPME GC-MS; an expert panel performed sensory analysis using descriptive methods. The arrangement of the mangoes significantly impacted the ripening procedures. Dense fruit arrangement induced a degradation of terpenes, a reduced formation of reaction products from the lipoxygenase pathway and less pronounced fruitiness and mango flavour. Principal component analysis based on volatile compounds and sensory properties showed a high correlation with the position in the ripening chamber. These data demonstrate the urgent need for further investigations of the postharvest ripening processes to increase mango quality.

Molecular Cloning, Characterization, and Expression of MiSOC1: A Homolog of the Flowering Gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 from Mango (Mangifera indica L).

MADS-box transcription factor plays a crucial role in plant development, especially controlling the formation and development of floral organs. Mango (Mangifera indica L) is an economically important fruit crop, but its molecular control of flowering is largely unknown. To better understand the molecular basis of flowering regulation in mango, we isolated and characterized the MiSOC1, a putative mango orthologs for the Arabidopsis SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1/AGAMOUS-LIKE 20 (SOC1/AGL20) with homology-based cloning and RACE. The full-length cDNA (GenBank accession No.: KP404094) is 945 bp in length including a 74 bp long 5' UTR and a 189 bp long 3' UTR and the open reading frame was 733 bps, encoding 223 amino acids with molecular weight 25.6 kD. Both sequence alignment and phylogenetic analysis all indicated that deduced protein contained a conservative MADS-box and semi-conservative K domain and belonged to the SOC1/TM3 subfamily of the MADS-box family. Quantitative real-time PCR was performed to investigate the expression profiles of MiSOC1 gene in different tissues/organs including root, stem, leaves, flower bud, and flower. The result indicated MiSOC1 was widely expressed at different levels in both vegetative and reproductive tissues/organs with the highest expression level in the stems' leaves and inflorescences, low expression in roots and flowers. The expression of MiSOC1 in different flower developmental stages was different while same tissue -specific pattern among different varieties. In addition, MiSOC1 gene expression was affect by ethephon while high concentration ethephon inhibit the expression of MiSOC1. Overexpression of MiSOC1 resulted in early flowering in Arabidopsis. In conclusion, these results suggest that MiSOC1 may act as induce flower function in mango.

Avaliação da estabilidade da capacidade antioxidante e de parâmetros físico-químicos de néctares de frutas caseiros / Assessment of the antioxidant capacity and of the physicalchemicalsparameters stability in homemade fruit nectars

Este estudo avaliou a capacidade antioxidante e os indicadores físico-químicos de néctares caseirosde laranja, manga e maracujá, mantidos sob refrigeração (5 ± 2 oC) por 24 horas. Os néctaresforam preparados em laboratório e mantidos sob refrigeração, simulando as condições domésticas.As análises foram realizadas após o preparo (T0) e durante o acondicionamento sob refrigeração(1 h, 4 h e 24 h). Os sólidos solúveis, pH e cor foram determinados respectivamente por refratometria,potenciometria e colorimetria. Carotenoides e ácido ascórbico foram analisados por cromatografialíquida de alta eficiência; a concentração de compostos fenólicos foi determinada utilizando-seo reagente de Folin Ciocalteau e a atividade antioxidante pelo teste do DPPH. Ácido ascórbico,β-caroteno e compostos fenólicos foram identificados em todos os néctares. Foram encontradosα-caroteno e β-criptoxantina no néctar de laranja e licopeno no néctar de manga. Durante 24 horasde refrigeração, os compostos analisados e a atividade antioxidante mantiveram-se estáveis. De formageral, os parâmetros físico-químicos também se mantiveram estáveis durante o período avaliado.Em conclusão, sob as condições utilizadas no presente estudo, os néctares não apresentaramalteração da capacidade antioxidante, podendo ser considerados fontes de carotenoides e vitamina C,mesmo se consumidos após 24 horas de preparo.

The objective of the study was to evaluate the antioxidant capacity and the physical-chemicalindicators of homemade nectars of orange, mango and passion fruit, kept under refrigeration(5 ± 2 °C) for 24 hours. The nectars were prepared in laboratory and kept under refrigerationsimulating the domestic conditions. The samples analyses were performed after their preparations(T0) and during the refrigerated storage (1 h, 4 h and 24 h). Soluble solids, pH and color weredetermined by refractometry, colorimetry and potentiometry, respectively. Carotenoids andascorbic acid were analyzed by high performance liquid chromatography, the concentrationof phenolic compounds were determined by using Folin Ciocalteau reagent, and the antioxidantactivity by the DPPH test. Ascorbic acid, β-carotene and phenolic compounds were identified inall of the analyzed nectars samples. The α-carotene and β-cryptoxanthin were found in orangenectar and the lycopene in mango nectar samples. During the refrigeration for 24 hours,the analyzed compounds and the antioxidant activity remained stable. In general, thephysical-chemicals parameters also remained stable during the storage for 24 hours. In conclusion,under the conditions used in this study, the nectars might be considered as antioxidant sources,even if consumed after being prepared 24 hours before.