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1.
Plants (Basel) ; 10(12)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34961114

RESUMO

The use of plant growth regulators (PGRs) is widespread in commercial table grape vineyards. The synthetic cytokinin CPPU is a PGR that is extensively used to obtain higher quality grapes. However, the effect of CPPU on berry firmness is not clear. The current study investigated the effects of pre-anthesis applications (BBCH15 and BBCH55 stages) of CPPU on 'Thompson Seedless' berry firmness at harvest through a combination of cytological, morphological, and biochemical analyses. Ovaries in CPPU-treated plants presented morphological changes related to cell division and cell wall modification at the anthesis stage (BBCH65). Moreover, immunofluorescence analysis with monoclonal antibodies 2F4 and LM15 against pectin and xyloglucan demonstrated that CPPU treatment resulted in cell wall modifications at anthesis. These early changes have major repercussions regarding the hemicellulose and pectin cell wall composition of mature fruits, and are associated with increased calcium content and a higher berry firmness at harvest.

2.
Plants (Basel) ; 10(3)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809443

RESUMO

The firmness of blueberry is one of its most significant quality attributes. Modifications in the composition of the cell wall have been associated with changes in the fruit firmness. In this work, cell wall components and calcium concentration in two blueberry cultivars with contrasting firmness phenotypes were evaluated at harvest and 30 days cold storage (0 °C). High performance anion-exchange chromatography with pulse amperometric detector (HPAEC-PAD) analysis was performed using the "Emerald" (firmer) and "Jewel" (softer) blueberry cultivars, showing increased glucose in the firmer cultivar after cold storage. Moreover, the LM15 antibody, which recognizes xyloglucan domains, displayed an increased signal in the Emerald cultivar after 30 d cold storage. Additionally, the antibody 2F4, recognizing a homogalacturonan calcium-binding domain, showed a greater signal in the firmer Emerald blueberries, which correlates with a higher calcium concentration in the cell wall. These findings suggest that xyloglucan metabolism and a higher concentration of cell wall calcium influenced the firmness of the blueberry fruit. These results open new perspectives regarding the role of cell wall components as xyloglucans and calcium in blueberry firmness.

3.
Food Chem ; 319: 126360, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32151896

RESUMO

Sweet cherry is a valuable non-climacteric fruit with elevated phytonutrients, whose fruit quality attributes are prone to rapid deterioration after harvest, especially peel damage and water loss of stem. Here the metabolic and transcriptional response of exogenous melatonin was assessed in two commercial cultivars of sweet cherry (Santina and Royal Rainier) during cold storage. Gene expression profiling revealed that cuticle composition and water movement may underlie the effect of melatonin in delaying weight loss. An effect of melatonin on total soluble solids and lower respiration rate was observed in both cultivars. Melatonin induces overexpression of genes related to anthocyanin biosynthesis, which correlates with increased anthocyanin levels and changes in skin color (Chroma). Our results indicate that along with modulating antioxidant metabolism, melatonin improves fruit quality traits by triggering a range of metabolic and gene expression changes, which ultimately contribute to extend sweet cherry postharvest storability.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Melatonina/farmacologia , Prunus avium/efeitos dos fármacos , Antocianinas/metabolismo , Frutas/metabolismo , Prunus avium/metabolismo
4.
Front Plant Sci ; 10: 795, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31293606

RESUMO

Avocado (Persea americana Mill) is rich in a variety of essential nutrients and phytochemicals; thus, consumption has drastically increased in the last 10 years. Avocado unlike other fruit is characterized by oil accumulation during growth and development and presents a unique carbohydrate pattern. There are few previous and current studies related to primary metabolism. The fruit is also quite unique since it contains large amounts of C7 sugars (mannoheptulose and perseitol) acting as transportable and storage sugars and as potential regulators of fruit ripening. These C7 sugars play a central role during fruit growth and development, but still confirmation is needed regarding the biosynthetic routes and the physiological function during growth and development of avocado fruit. Relatively recent transcriptome studies on avocado mesocarp during development and ripening have revealed that most of the oil is synthesized during early stages of development and that oil synthesis is halted when the fruit is harvested (pre-climacteric stage). Most of the oil is accumulated in the form of triacylglycerol (TAG) representing 60-70% in dry basis of the mesocarp tissue. During early stages of fruit development, high expression of transcripts related to fatty acid and TAG biosynthesis has been reported and downregulation of same genes in more advanced stages but without cessation of the process until harvest. The increased expression of fatty acid key genes and regulators such as PaWRI1, PaACP4-2, and PapPK-ß-1 has also been reported to be consistent with the total fatty acid increase and fatty acid composition during avocado fruit development. During postharvest, there is minimal change in the fatty acid composition of the fruit. Almost inexistent information regarding the role of organic acid and amino acid metabolism during growth, development, and ripening of avocado is available. Cell wall metabolism understanding in avocado, even though crucial in terms of fruit quality, still presents severe gaps regarding the interactions between cell wall remodeling, fruit development, and postharvest modifications.

5.
BMC Genomics ; 20(1): 108, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30727956

RESUMO

BACKGROUND: Avocado (Persea americana Mill.) is a basal angiosperm from the Lauraceae family. This species has a diploid genome with an approximated size of ~ 920 Mbp and produces a climacteric, fleshy and oily fruit. The flowering and fruit set are particularly prolonged processes, lasting between one to three months, generating important differences in physiological ages of the fruit within the same tree. So far there is no detailed genomic information regarding this species, being the cultivar 'Hass' especially important for avocado growers worldwide. With the aim to explore the fruit avocado transcriptome and to identify candidate biomarkers to monitore fruit development, we carried out an RNA-Seq approach during 4 stages of 'Hass' fruit development: 150 days after fruit set (DAFS), 240 DAFS, 300 DAFS (harvest) and 390 DAFS (late-harvest). RESULTS: The 'Hass' de novo transcriptome contains 62,203 contigs (x̅=988 bp, N50 = 1050 bp). We found approximately an 85 and 99% of complete ultra-conserved genes in eukaryote and plantae database using BUSCO (Benchmarking Universal Single-Copy Orthologs) and CEGMA (Core Eukaryotic Gene Mapping Approach), respectively. Annotation was performed with BLASTx, resulting in a 58% of annotated contigs (90% of differentially expressed genes were annotated). Differentially expressed genes analysis (DEG; with False Discovery Rate ≤ 0.01) found 8672 genes considering all developmental stages. From this analysis, genes were clustered according to their expression pattern and 1209 genes show correlation with the four developmental stages. CONCLUSIONS: Candidate genes are proposed as possible biomarkers for monitoring the development of the 'Hass' avocado fruit associated with lipid metabolism, ethylene signaling pathway, auxin signaling pathway, and components of the cell wall.


Assuntos
Frutas/crescimento & desenvolvimento , Persea/genética , Proteínas de Plantas/genética , Transcriptoma , Frutas/metabolismo , Persea/crescimento & desenvolvimento , Persea/metabolismo , Análise de Sequência de RNA
6.
J Agric Food Chem ; 67(5): 1598-1607, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30632375

RESUMO

Cold storage of fruit is one of the methods most commonly employed to extend the postharvest lifespan of peaches ( Prunus persica (L.) Batsch). However, fruit quality in this species is affected negatively by mealiness, a physiological disorder triggered by chilling injury after long periods of exposure to low temperatures during storage and manifested mainly as a lack of juiciness, which ultimately modifies the organoleptic properties of peach fruit. The aim of this study was to identify molecular components and metabolic processes underlying mealiness in susceptible and nonsusceptible segregants. Transcriptome and qRT-PCR profiling were applied to individuals with contrasting juiciness phenotypes in a segregating F2 population. Our results suggest that mealiness is a multiscale phenomenon, because juicy and mealy fruit display distinctive reprogramming processes affecting translational machinery and lipid, sugar, and oxidative metabolism. The candidate genes identified may be useful tools for further crop improvement.


Assuntos
Frutas/química , Perfilação da Expressão Gênica , Prunus persica/genética , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus persica/química , Prunus persica/metabolismo
7.
Food Chem ; 268: 492-497, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30064789

RESUMO

Firm berries are highly appreciated by table grape consumers. Cell wall composition is one of the main factors influencing the firmness of table grape berries. Nevertheless, the biological factors driving changes in berry firmness remain unclear. In the present work, we evaluated the firmness of berries of Vitis vinifera cv. Thompson Seedless. We selected two orchards displaying contrasting berry firmness and evaluated polar metabolites and cell wall composition. Our results suggest that berries from the soft orchard exhibited a higher accumulation of sugars at veraison whereas berries from the hard orchard accumulated the same sugars at harvest plus a higher amount of glucose monosaccharide at the cell wall. Thus, this study opens new insights about a connection between metabolic and cell wall changes with fruit firmness in a table grape variety, suggesting that it is possible to use metabolomic tools to identify metabolic biomarkers associated with table grape berry firmness.


Assuntos
Parede Celular/química , Vitis/química , Frutas , Metabolômica
8.
Plant Physiol Biochem ; 128: 142-151, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29778838

RESUMO

The avocado is a climacteric fruit and begins a softening process after harvest. During ripening, the mesocarp changes in texture, and this affects fruit quality and cold storage capacity. Softening is commonly associated with cell wall disassembly in climacteric fruits. However, changes in the cell wall structure and composition during avocado softening are poorly understood. To understand this process, cell wall pectins in "Hass" avocado fruit were studied during ripening at 20 °C after harvest and after cold storage. Additionally, avocados were treated with 1-MCP to evaluate the delay in softening. Biochemical analysis showed a decrease in galacturonic acid (GalA) in alcohol-insoluble residues (AIR) and water-soluble pectin concomitant to softening, paralleled by an increase in polygalacturonase (PG) activity. In the same way, the ß-galactosidase activity increased in soft avocado fruit, along with a reduction in galactose in cell wall material and the Na2CO3-soluble fraction. The arabinose content in the cell wall material did not change during softening. However, there was a change in arabinose ratios between the different fractions of pectin, mainly in the fractions soluble in water and in Na2CO3. The cold storage of avocado fruit did not induce softening of the fruit, but the content of GalA showed a substantial decrease, accompanied by an increase in PG activity. Thus, our work supports the hypothesis that the solubilization of neutral sugars such as arabinose and rhamnose, as well as the loss of galactose content mediated by the enzyme ß-galactosidase, were the main factors that began the coordinated action of cell wall remodeling enzymes that resulted in the loss of firmness of avocado fruit.


Assuntos
Parede Celular/metabolismo , Frutas/metabolismo , Pectinas/metabolismo , Persea/metabolismo , Proteínas de Plantas/metabolismo , Poligalacturonase/metabolismo , beta-Galactosidase/metabolismo
9.
PLoS One ; 13(1): e0190087, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29320527

RESUMO

Ripening is one of the key processes associated with the development of major organoleptic characteristics of the fruit. This process has been extensively characterized in climacteric fruit, in contrast with non-climacteric fruit such as grape, where the process is less understood. With the aim of studying changes in gene expression during ripening of non-climacteric fruit, an Illumina based RNA-Seq transcriptome analysis was performed on four developmental stages, between veraison and harvest, on table grapes berries cv Thompson Seedless. Functional analysis showed a transcriptional increase in genes related with degradation processes of chlorophyll, lipids, macromolecules recycling and nucleosomes organization; accompanied by a decrease in genes related with chloroplasts integrity and amino acid synthesis pathways. It was possible to identify several processes described during leaf senescence, particularly close to harvest. Before this point, the results suggest a high transcriptional activity associated with the regulation of gene expression, cytoskeletal organization and cell wall metabolism, which can be related to growth of berries and firmness loss characteristic to this stage of development. This high metabolic activity could be associated with an increase in the transcription of genes related with glycolysis and respiration, unexpected for a non-climacteric fruit ripening.


Assuntos
Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Transcriptoma , Vitis/genética , Frutas/metabolismo , Perfilação da Expressão Gênica , Ontologia Genética , Redes e Vias Metabólicas/genética , Fenótipo , Proteínas de Plantas/genética , RNA de Plantas/biossíntese , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Vitis/crescimento & desenvolvimento , Vitis/metabolismo
10.
J Agric Food Chem ; 65(29): 6049-6057, 2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28669186

RESUMO

Lipoxygenase (LOX) is an important contributor to aroma compounds in most fresh produce; however, little is known about the LOX pathway in pepino (Solanum muricatum Aiton) fruit. We explored the LOX aroma compounds produced by the flesh and the peel and identified eight putative LOX genes expressed in both tissues during fruit growth and development during two consecutive seasons. This study shows that pepino produces C5, C6, and C9 LOX-derived compounds. Odorant C9 volatiles were produced during immature stages with a concomitant decrease when the fruit ripens, whereas C5 and C6 compounds were formed throughout ripening. trans-2-Hexenal and its alcohol were produced in the peel, but not detected in the flesh. The expression of three genes, SmLOXD (putative 13-LOX), SmLOXB, and SmLOX5-like1 (putative 9-LOXs), increased during fruit ripening. These genes may account for aroma volatiles in pepino. Here, we discuss the possible roles of individual LOX genes in pepino.


Assuntos
Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Lipoxigenase/metabolismo , Proteínas de Plantas/metabolismo , Solanum/enzimologia , Compostos Orgânicos Voláteis/metabolismo , Aldeídos/metabolismo , Frutas/enzimologia , Frutas/genética , Lipoxigenase/química , Lipoxigenase/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Solanum/genética , Solanum/crescimento & desenvolvimento , Especificidade por Substrato
11.
Plant Physiol Biochem ; 115: 286-297, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28412633

RESUMO

'Crimson Seedless' is one of the most important table grape varieties in Chile, but under certain environmental conditions, the fruit exhibits inadequate red color development, causing economic losses due to lower product quality. The use of plant growth regulators, such as abscisic acid (ABA) and ethylene, during development increases the anthocyanin content of the skin, improving the color of the berry. Recently, sucrose has been identified as a signaling molecule capable of regulating the expression of genes of the anthocyanin biosynthesis pathway. The aim of this study was to analyze the effect of application of ABA and/or sucrose on color development and their relationship with anthocyanin metabolism. Applications of ABA (400 ppm or 200 ppm) and/or sucrose (90 mM) were performed close to the véraison stage. During development and at harvest, quality attributes such as berry firmness, total soluble solids and titratable acidity were not affected by these treatments. Increased red color development was observed in fruits treated with ABA and/or sucrose, due to accumulation of anthocyanins. Fruits subjected to sucrose treatment showed higher levels of anthocyanins than untreated fruits but lower levels than fruits treated with ABA. Increased expression of genes involved in anthocyanin biosynthesis was observed in ABA- and sucrose-treated fruits compared to untreated fruits. Based on these findings, we demonstrated that sucrose improved fruit color development by increasing synthesis and accumulation of anthocyanins, thus allowing earlier harvests and improving table grape quality.


Assuntos
Ácido Abscísico/farmacologia , Antocianinas/metabolismo , Proteínas de Plantas/metabolismo , Sacarose/farmacologia , Vitis/efeitos dos fármacos , Vitis/metabolismo , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas , Pigmentação/efeitos dos fármacos , Proteínas de Plantas/genética
12.
Molecules ; 21(5)2016 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-27120592

RESUMO

Cherimoya (Annona cherimola Mill.) is a subtropical fruit characterized by a significant increase in organic acid levels during ripening, making it an interesting model for studying the relationship between acidity and fruit flavor. In this work, we focused on understanding the balance between the concentration of organic acids and the gene expression and activity of enzymes involved in the synthesis and degradation of these metabolites during the development and ripening of cherimoya cv. "Concha Lisa". Our results showed an early accumulation of citric acid and other changes associated with the accumulation of transcripts encoding citrate catabolism enzymes. During ripening, a 2-fold increase in malic acid and a 6-fold increase in citric acid were detected. By comparing the contents of these compounds with gene expression and enzymatic activity levels, we determined that cytoplasmic NAD-dependent malate dehydrogenase (cyNAD-MDH) and mitochondrial citrate synthase (mCS) play important regulatory roles in the malic and citric acid biosynthetic pathways.


Assuntos
Ácidos Acíclicos/metabolismo , Annona/fisiologia , Expressão Gênica , Malato Desidrogenase/genética , Annona/genética , Ácido Cítrico/metabolismo , DNA de Plantas/análise , Regulação da Expressão Gênica de Plantas , Malatos/metabolismo , Redes e Vias Metabólicas , Proteínas de Plantas/genética , Análise de Sequência de DNA
13.
Food Chem ; 190: 403-411, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26212989

RESUMO

Pouteria lucuma is an Andean fruit from pre-Incas' times highly appreciated due to its characteristic flavor and taste in its homeland. We characterized the primary (e.g., sugars and organic acids), and secondary (e.g., phenolics and carotenoids) and in vitro antioxidant and antihyperglycemic properties of Rosalia, Montero and Leiva 1 lucuma biotypes. Significant differences were found in these metabolites and functional properties related to biotype and ripeness stage. Results showed significant amounts of sugars (119.4-344 mg total sugars g(-1)DW) and organic acids (44.4-30.0 mg g(-1)DW) and functional associated compounds such as ascorbic acid (0.35-1.07 mg g(-1)DW), total phenolics (0.7-61.6 mg GAE g(-1)DW) and total carotenoids (0.22-0.50 mg ß-carotene g(-1)DW). Important in vitro antioxidant and antihyperglycemic properties were found and provide the base for the standardization of lucuma harvest and postharvest focused not only on the enhancement of sensory but functional properties.


Assuntos
Antioxidantes/farmacologia , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , Pouteria/metabolismo , Carotenoides/análise , Frutas/química , Fenóis/análise , Pouteria/química , alfa-Amilases/antagonistas & inibidores
14.
J Proteomics ; 131: 71-81, 2016 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-26459401

RESUMO

Peaches are stored at low temperatures to delay ripening and increase postharvest life. However some varieties are susceptible to chilling injury,which leads to fruit mealiness, browning and flesh bleeding. In order to identify potentialmarkers associated with chilling injury,we performed proteomic analyses on a segregating population with contrasting susceptibility to chilling-induced mealiness. Chilling-induced mealiness was assessed by measuring juiciness in fruits that have been stored in cold and then allowed to ripen. Fruitmesocarp and leaf proteome from contrasting segregants were analyzed using 2-DE gels. Comparison of protein abundance between segregants revealed 133 spots from fruit mesocarp and 36 from leaf. Thirty four fruit mesocarp proteins were identified from these spots. Most of these proteins were related to ethylene synthesis, ABA response and stress response. Leaf protein analyses identified 22 proteins, most of which related to energy metabolism. Some of the genes that code for these proteins have been previously correlated with chilling injury through transcript analyses and co-segregation with mealiness QTLs. The results from this study, further deciphers the molecular mechanisms associated with chilling response in peach fruit, and identifies candidate proteins linked to mealiness in peach which may be used as putative markers for this trait.


Assuntos
Proteínas e Peptídeos de Choque Frio/metabolismo , Resposta ao Choque Frio/fisiologia , Análise de Alimentos/métodos , Frutas/metabolismo , Proteínas de Plantas/metabolismo , Prunus persica/metabolismo , Manipulação de Alimentos/métodos , Proteoma/metabolismo
15.
Hortic Res ; 2: 15003, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26504564

RESUMO

Lipoxygenase (LOX) is an important contributor to the formation of aroma-active C6 aldehydes in apple (Malus × domestica) fruit upon tissue disruption but little is known about its role in autonomously produced aroma volatiles from intact tissue. We explored the expression of 22 putative LOX genes in apple throughout ripening, but only six LOXs were expressed in a ripening-dependent manner. Recombinant LOX1:Md:1a, LOX1:Md:1c, LOX2:Md:2a and LOX2:Md:2b proteins showed 13/9-LOX, 9-LOX, 13/9-LOX and 13-LOX activity with linoleic acid, respectively. While products of LOX1:Md:1c and LOX2:Md:2b were S-configured, LOX1:Md:1a and LOX2:Md:2a formed 13(R)-hydroperoxides as major products. Site-directed mutagenesis of Gly567 to an alanine converted the dual positional specific LOX1:Md:1a to an enzyme with a high specificity for 9(S)-hydroperoxide formation. The high expression level of the corresponding MdLOX1a gene in stored apple fruit, the genetic association with a quantitative trait locus for fruit ester and the remarkable agreement in regio- and stereoselectivity of the LOX1:Md:1a reaction with the overall LOX activity found in mature apple fruits, suggest a major physiological function of LOX1:Md:1a during climacteric ripening of apples. While LOX1:Md:1c, LOX2:Md:2a and LOX2:Md:2b may contribute to aldehyde production in immature fruit upon cell disruption our results furnish additional evidence that LOX1:Md:1a probably regulates the availability of precursors for ester production in intact fruit tissue.

16.
J Plant Physiol ; 179: 100-5, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25847526

RESUMO

Red Raspberry (Rubus idaeus) is traditionally classified as non-climacteric, and the role of ethylene in fruit ripening is not clear. The available information indicates that the receptacle, a modified stem that supports the drupelets, is involved in ethylene production of ripe fruits. In this study, we report receptacle-related ethylene biosynthesis during the ripening of fruits of cv. Heritage. In addition, the expression pattern of ethylene biosynthesis transcripts was evaluated during the ripening process. The major transcript levels of 1-aminocyclopropane-1-carboxylic acid synthase (RiACS1) and 1-aminocyclopropane-1-carboxylic acid oxidase (RiACO1) were concomitant with ethylene production, increased total soluble solids (TSS) and decreased titratable acidity (TA) and fruit firmness. Moreover, ethylene biosynthesis and transcript levels of RiACS1 and RiACO1 were higher in the receptacle, sustaining the receptacle's role as a source of ethylene in regulating the ripening of raspberry.


Assuntos
Vias Biossintéticas/genética , Etilenos/biossíntese , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Rubus/anatomia & histologia , Rubus/genética , Sequência de Aminoácidos , Respiração Celular/genética , Flores/genética , Frutas/genética , Dados de Sequência Molecular , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Rubus/enzimologia , Rubus/crescimento & desenvolvimento , Alinhamento de Sequência
17.
Molecules ; 20(3): 3667-80, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25711424

RESUMO

Postharvest softening of grape berries is one of the main problems affecting grape quality during export. Cell wall disassembly, especially of pectin polysaccharides, has been commonly related to fruit softening, but its influence has been poorly studied in grapes during postharvest life. In order to better understand this process, the Thompson seedless (TS) variety, which has significantly decreased berry texture after prolonged cold storage, was compared to NN107, a new table grape variety with higher berry firmness. Biochemical analysis revealed a greater amount of calcium in the cell wall of the NN107 variety and less reduction of uronic acids than TS during cold storage. In addition, the activity of polygalacturonase was higher in TS than NN107 berries; meanwhile pectin methylesterase activity was similar in both varieties. Polysaccharide analysis using carbohydrate gel electrophoresis (PACE) suggests a differential pectin metabolism during prolonged cold storage. Results revealed lower pectin fragments in TS after 60 days of cold storage and shelf life (SL) compared to 30 days of cold storage and 30 + SL, while NN107 maintained the same fragment profile across all time points evaluated. Our results suggest that these important differences in cell wall metabolism during cold storage could be related to the differential berry firmness observed between these contrasting table grape varieties.


Assuntos
Cálcio/metabolismo , Parede Celular/metabolismo , Frutas/química , Pectinas/metabolismo , Ácidos Urônicos/análise , Vitis/química , Hidrolases de Éster Carboxílico/metabolismo , Temperatura Baixa , Armazenamento de Alimentos , Frutas/anatomia & histologia , Frutas/classificação , Frutas/metabolismo , Fenótipo , Poligalacturonase/metabolismo , Polissacarídeos/metabolismo , Vitis/anatomia & histologia , Vitis/classificação , Vitis/metabolismo
18.
J Agric Food Chem ; 59(24): 13295-9, 2011 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-22087802

RESUMO

Cherimoyas (Annona cherimola), like other subtropical/tropical fruits, are susceptible to damage from exposure to temperatures between 0 and 5 °C (chilling injury, CI), which may affect fruit quality. To increase our understanding of the molecular mechanisms involved in the CI response, a forward suppression subtractive hybridization (SSH) cDNA library was constructed. In this work, we obtained 75 genes that could potentially be involved in the CI response. The CI induced activation of genes that are involved in a range of metabolic pathways, such as primary metabolism, transport, and endomembrane traffic, among others. We also characterized the expression of 12 selected genes in different A. cherimola tissues by polymerase chain reaction (PCR), and we confirmed the differential expression of a subset in CI fruits by real-time quantitative PCR (qPCR). The expression of six A. cherimola genes: annexin (AcAnex), UDP-glucose pyrophosphorylase (AcUGP), syntaxin of plants 71 (AcSyp71), 1-aminocyclopropane-1-carboxylic-acid synthase (AcACS), ubiquitin carrier-like protein (AcUCP), and enolase (AcEnol), was up-regulated after cold storage for 12 days at 0 °C. These results imply that selected genes could be related to the development of internal browning observed in cherimoyas after exposure to CI conditions. The information generated in this study provides new clues that may aid in understanding the cherimoya ripening process.


Assuntos
Annona/genética , Temperatura Baixa , Frutas/genética , Expressão Gênica , Proteínas de Plantas/genética , DNA de Plantas/análise , Regulação da Expressão Gênica de Plantas , Reação de Maillard
19.
Plant Physiol Biochem ; 47(5): 435-40, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19233665

RESUMO

Fruit aroma is a complex trait, particularly in terms of the number of different biosynthetic pathways involved, the complexity of the final metabolites, and their regulation. In order to understand the underlying biochemical processes involved in apricot aroma, four cDNAs (Pa-aat, EU784138; Pa-adhEU395433; Pa-pdcEU395434; and Pa-loxEU439430) encoding an alcohol acyl transferase (AAT), alcohol dehydrogenase (ADH), pyruvate decarboxylase (PDC), and lipoxygenase (LOX), respectively, were isolated and characterized at four stages of maturity in Prunus armeniaca L. cv. Modesto. We observed a reduction in aldehyde and alcohol production between early-harvested fruit and late-harvest fruit, concomitant with an increase in ester production. qPCR analyses showed that the expression levels of the adh gene and the lox gene stayed constant at all stages. Interestingly, aat levels showed a sharp increase in the late-harvest stages concurrent with the changes observed in ester levels. The significance of these changes in relation to aroma production in apricot is discussed.


Assuntos
Perfilação da Expressão Gênica , Odorantes/análise , Proteínas de Plantas/genética , Prunus/genética , Aciltransferases/genética , Aciltransferases/metabolismo , Álcool Desidrogenase/genética , Álcool Desidrogenase/metabolismo , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Lipoxigenase/genética , Lipoxigenase/metabolismo , Dados de Sequência Molecular , Proteínas de Plantas/metabolismo , Prunus/metabolismo , Prunus/fisiologia , Piruvato Descarboxilase/genética , Piruvato Descarboxilase/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Volatilização
20.
J Agric Food Chem ; 55(22): 9208-18, 2007 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-17907770

RESUMO

Cherimoya (Annona cherimola Mill.) fruit is an attractive candidate for food processing applications as fresh cut. However, along with its desirable delicate taste, cherimoya shows a marked susceptibility to browning. This condition is mainly attributed to polyphenol oxidase activity (PPO). A general lack of knowledge regarding PPO and its role in the oxidative loss of quality in processed cherimoya fruit requires a better understanding of the mechanisms involved. The work carried out included the cloning of a full-length cDNA, an analysis of its properties in the deduced amino sequence, and linkage of its mRNA levels with enzyme activity in mature and ripe fruits after wounding. The results showed one gene different at the nucleotide level when compared with previously reported genes, but a well-conserved protein, either in functional and in structural terms. Cherimoya PPO gene (Ac-ppo, GenBank DQ990911) showed to be present apparently in one copy of the genome, and its transcripts could be significantly detected in leaves and less abundantly in flowers and fruits. Analysis of wounded matured and ripened fruits revealed an inductive behavior for mRNA levels in the flesh of mature cherimoya after 16 h. Although the highest enzymatic activity was observed on rind, a consistent PPO activity was detected on flesh samples. A lack of correlation between PPO mRNA level and PPO activity was observed, especially in flesh tissue. This is probably due to the presence of monophenolic substrates inducing a lag period, enzyme inhibitors and/or diphenolic substrates causing suicide inactivation, and proenzyme or latent isoforms of PPO. To our knowledge this is the first report of a complete PPO sequence in cherimoya. Furthermore, the gene is highly divergent from known nucleotide sequences but shows a well conserved protein in terms of its function, deduced structure, and physiological role.


Assuntos
Annona/enzimologia , Catecol Oxidase/genética , Catecol Oxidase/metabolismo , DNA de Plantas/química , Frutas/enzimologia , Reação de Maillard , Sequência de Aminoácidos , Sequência de Bases , Catecol Oxidase/química , Clonagem Molecular , Expressão Gênica , Dados de Sequência Molecular , RNA Mensageiro/análise
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