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‣ Pectin methylesterase activity and ascorbic acid content from guava fruit, cv. Predilecta, in different phases of development

Carvalho, Adelino B.; De Assis, Sandra A.; Cerqueira Leite, Katia M. S.; Bach, Erna E.; de Faria Oliveira, Olga M. M.
Fonte: Taylor & Francis Ltd Publicador: Taylor & Francis Ltd
Tipo: Artigo de Revista Científica Formato: 255-265
Português
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); The guava pectin methylesterase (PME) specific activity and vitamin C were assayed in samples from different phases of guava fruit development. The PME enzyme from guava was extracted with borate-acetate buffer, 50 mol/l, pH 8.0, in the presence of NaCl 0.3 mol/l. The results showed PME optimum activity at pH 9 and 95C, and it is a thermostable enzyme. Guava PME retained 96.8% of activity after 300 min in 90C. Electrophoresis showed that guava PME contained two isoforms, one with 57 kDa molecular mass. The analyses of the different phases of guava maturation showed that ascorbic acid decreases during the maturation process, but PME activity increases with maturation.

‣ Partial purification and characterization of pectin methylesterase from acerola (Malpighia glabra L.)

De Assis, S. A.; Martins, ABG; Guaglianoni, D. G.; Oliveira, OMMD
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica Formato: 4103-4107
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The enzyme pectin methylesterase (PME) is present in acerola fruit and was partially purified by gel filtration on Sephadex G-100. The results of gel filtration showed different PME isoforms. The total PME (precipitated by 70% salt saturation) and one of these isoforms (fraction from Sephadex G-100 elution) that showed a molecular mass of 15.5 +/- 1.0 kDa were studied. The optimum pH values of both forms were 9.0. The total and the partially purified PME showed that PME specific activity increases with temperature, the total acerola PME retained 13.5% of its specific activity after 90 min of incubation at 98 degreesC. The partially purified acerola (PME isoform) showed 125.5% of its specific activity after 90 min of incubation at 98 degreesC. The K-m values of the total PME and the partially purified PME isoform were 0.081 and 0.12 mg/mL, respectively. The V-max values of the total PME and the partially purified PME were 2.92 and 6.21 mumol/min/mL/mg of protein, respectively.

‣ Activity and Process Stability of Purified Green Pepper (Capsicum annuum) Pectin Methylesterase

Castro, Sónia Marília; Van Loey, Ann; Saraiva, Jorge Alexandre; Smout, Chantal; Hendrickx, Marc
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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Pectin methylesterase (PME) from green bell peppers (Capsicum annuum) was extracted and purified by affinity chromatography on a CNBr-Sepharose-PMEI column. A single protein peak with pectin methylesterase activity was observed. For the pepper PME, a biochemical characterization in terms of molar mass (MM), isoelectric points (pI), and kinetic parameters for activity and thermostability was performed. The optimum pH for PME activity at 22 °C was 7.5, and its optimum temperature at neutral pH was between 52.5 and 55.0 °C. The purified pepper PME required the presence of 0.13 M NaCl for optimum activity. Isothermal inactivation of purified pepper PME in 20 mM Tris buffer (pH 7.5) could be described by a fractional conversion model for lower temperatures (55?57 °C) and a biphasic model for higher temperatures (58?70 °C). The enzyme showed a stable behavior toward high-pressure/temperature treatments. Keywords: Capsicum annuum; pepper; pectin methylesterase; purification; characterization; thermal and high-pressure stability

‣ Process stability of Capsicum annuum pectin methylesterase in model systems, pepper puree and intact pepper tissue

Castro, Sónia Marília; Loey, Ann; Saraiva, Jorge Alexandre; Smout, Chantal; Hendrickx, Marc
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
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Process stability studies towards temperature and/or pressure on pepper pectin methylesterase (PME) were carried out in different systems (purified form, crude extract, pepper pieces and puree) at pH 5.6. Within the temperature range studied (22–80 °C, 5 min), pepper PME in pure form and crude extract was gradually inactivated showing a biphasic inactivation behaviour, indicating the presence of isoenzymes of different thermostability. Pepper samples heated for 15 min showed a maximum of residual PME activity around 55 °C. Isothermal inactivation of pepper PME in purified form and crude extract at pH 5.6 could be described by a biphasic inactivation model for the temperature range studied (62–76 °C). A stable behaviour towards high-pressure/temperature treatments (400–800 MPa/25–60 °C) was observed for crude extract and purified pepper PME. PME in pepper puree samples revealed to be very pressure stable. Mild temperatures combined with pressure treatments seem to increase the extractability from PME in pepper tissue, probably due to the effect on the cell structure.

‣ Identification of pressure/temperature combinations for optimal pepper (Capsicum annuum) pectin methylesterase activity

Castro, Sónia Marília; Loey, Ann Van; Saraiva, Jorge Alexandre; Smout, Chantal; Hendrickx, Marc
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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Pectin methylesterase (PME) was extracted from green bell peppers and purified by affinity chromatography. The optimal pectin and salt concentrations for the PME catalysed reaction were investigated. Purified pepper PME activity was studied during combined high-pressure/temperature treatments (18–65 °C, 0.1–600 MPa) in a model system of pectin at pH 5.6. The activity of purified pepper PME showed a maximum at 200 MPa and 55 °C. A third-degree polynomial model (derived from a thermodynamic model) was successfully used to describe the heat–pressure dependence of the initial rates of purified pepper PME-catalyzed methanol formation.

‣ Inactivation of pepper (Capsicum annuum) pectin methylesterase by combined high-pressure and temperature treatments

Castro, Sónia Marília; Loey, Ann Van; Saraiva, Jorge Alexandre; Smout, Chantal; Hendrickx, Marc
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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Pressure and/or temperature inactivation (at mild temperature, 10–64 °C, in combination with high-pressure, 0.1–800 MPa) of the labile fraction of purified pepper pectin methylesterase (PME) was studied in a model system at pH 5.6. Inactivation of the labile fraction under mild-heat and high-pressure conditions could be accurately described by a fractional conversion model, while a biphasic model was used to estimate the inactivation rate constant of both fractions at more drastic conditions of temperature/pressure. At lower pressures (P ⩽ 300 MPa) and high temperatures (>54 °C), an antagonistic effect of pressure and temperature was observed. Pressure and temperature dependence of the inactivation rate constants of the labile fraction was quantified using the Eyring and Arrhenius relations, respectively. A third-degree polynomial model (derived from the thermodynamic model) was successfully applied to describe the temperature/pressure dependence of the inactivation rate constants of the labile pepper PME fraction.

‣ Thermal and high-pressure stability of purified pectin methylesterase from plums (Prunus domestica)

Nunes, Claudia S.; Castro, Sonia M.; Saraiva, Jorge A.; Coimbra, Manuel A.; Hendrickx, MarcE; Loey, AnnMVan
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica
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Pectin methylesterase (PME) from greengage plums (Prunus domestica) has been extracted and purified using affinity chromatography. Only one band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was obtained, with an estimated molecular weight of 31 kDa. On isoelectric focusing electrophoresis, two bands with neutral isoelectric points (6.8 and 7.0) were detected. The optimal pH and temperature for plum PME activity were 7.5 and 65C, respectively. A study of purified plum PME thermostability was performed at pH 7.5 and 4.0, indicating a higher thermostability at pH 7.5 than at pH 4.0. A biphasic inactivation behavior was observed for thermal treatments (54-70C), whereas its pressure inactivation could be described by a first-order kinetic model in a pressure range of 650-800 MPa at 25C. Purified plum PME was found to be relatively stable to thermal and pressure (

‣ Thermal inactivation of pectin methylesterase from peppers (Capsicum annum)

Castro, S. M.; Van Loey, A.; Saraiva, J.; Smout, C.; Hendrickx, M.
Fonte: Universiteit Gent Publicador: Universiteit Gent
Tipo: Conferência ou Objeto de Conferência
Português
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Pectin methylesterase (PME) from green bell peppers (Capsicum annuum) was extracted and purified. Isothermal inactivation of purified pepper PME at pH 7.5 could be described by a fractional conversion model for lower temperatures (55-57°C) and a biphasic model for higher temperatures (58-70°C).

‣ The effect of combined temperature-pressure treatments on pepper (Capsicum annuum) pectin methylesterase in model systems

Castro, S.; Van Loey, A.; Saraiva, J.; Hendrickx, M.
Fonte: SPQ, ESAV Publicador: SPQ, ESAV
Tipo: Conferência ou Objeto de Conferência
Português
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At atmospheric pressure, purified pepper PME starts to inactivate at temperatures higher than 54°C. But when mild temperaturelhigh-pressure treatments are applied (T254"C, P<300MPa), an antagonistic effect of pressure and temperature is observed. Pressure seems to wield a protective effect on heat inactivation. Within the thermallhigh-pressure domain investigated, maximal pepper PME activity in the presence of pectin was observed at 200MPaI55"C. At temperatures lower than 50°C, PME activity decreased with pressure; while at temperatures higher than 50°C, there was an enhancement of the pressure effect from 0.1-200MPa, followed by a decrease for higher pressures.

‣ Determination of pectin methylesterase activity in commercial pectinases and study of the inactivation kinetics through two potentiometric procedures

Gonzalez,Samantha Lemke; Rosso,Neiva Deliberali
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
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Pectinases are enzymes that degrade pectic substances and are widely used in juice and fruit beverages to improve the quality of the process. The objective of this study was to determine the optimum pH and temperature of two samples of commercial pectinases and propose an alternative procedure to determine the residual activity comparing the data with those of the traditional procedure. The pectin methylesterase (PME) activity in Pectinex 100 L Plus and Panzyn Clears was determined by potentiometry. The reaction consisted of 5.00 mg.mL-1 apple pectin, 0.100 mol.L-1 NaCl, and 50 µL enzyme to a total volume of 30 mL. The pectin reaction in the presence of PME in all experiments revealed a first order kinetics. The PME in the two enzyme preparations showed higher activity at pH 4.0 to 4.5 and temperature of 45 ºC. From the results of both procedures ΔV NaOH/Δt and ΔpH/Δt, it was concluded that the inactivation of PME occurred at 75 ºC. The results obtained from the ratio ΔpH/Δt showed good correlation with those obtained from the ratio ΔV NaOH/Δt. In the reaction accompanied by the ratio ΔpH/Δt, the release of H3O+ occurred in the real time reaction.

‣ Pectin methylesterase activity determined by different methods and thermal inactivation of exogenous pme in mango juice

Gonzalez,Samantha Lemke; Lima,Regina Cristina Aparecida; Carneiro,Eliana Beleski Borba; Almeida,Mareci Mendes de; Rosso,Neiva Deliberali
Fonte: Editora da Universidade Federal de Lavras Publicador: Editora da Universidade Federal de Lavras
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2011 Português
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Pectin methylesterase (PME) hydrolyzes methyl ester groups in pectin chains to form carboxylic groups, releasing methanol and H3O+. The aim of this study was to determine PME activity in samples of pectinases by UV-VIS spectroscopy, to measure the acid and methanol produced in the reaction of pectin with pectinase and to verify the thermal inactivation of exogenous PME in mango juice. The activity of PME in samples of pectinase was determined by potentiometry, UV-VIS spectroscopy, and by the action of alcohol oxidase. The reaction showed greater activity at pH 4.0 to 4.5 and at a temperature of 45° C. PME activity determined by UV-VIS spectroscopy with bromophenol blue indicator showed a good correlation with the activity determined by potentiometry and with alcohol oxidase. The results showed that bromophenol blue indicators can be used to determine PME activity in samples of pectinases where the optimum pH is located in the acidic range. The thermal inactivation of exogenous PME in mango juice occurred at 75° C for 20 min of exposure.

‣ Ralstonia solanacearum Pectin Methylesterase Is Required for Growth on Methylated Pectin but Not for Bacterial Wilt Virulence

Tans-Kersten, Julie; Guan, Yanfen; Allen, Caitilyn
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /12/1998 Português
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Ralstonia (Pseudomonas) solanacearum causes bacterial wilt, a serious disease of many crop plants. The pathogen produces several extracellular plant cell wall-degrading enzymes, including polygalacturonases (PGs) and pectin methylesterase (Pme). Pme removes methyl groups from pectin, thereby facilitating subsequent breakdown of this cell wall component by PGs, which are known bacterial wilt virulence factors. R. solanacearum PGs could not degrade 93% methylated pectin unless the substrate was first demethylated by Pme, but as the degree of methylation of the pectin substrate decreased, PG activity increased. Primers derived from a published pme sequence generated an 800-bp DNA probe fragment, which identified Pme-encoding plasmids from a R. solanacearum genomic library. A pme chromosomal mutant had no detectable Pme activity in vitro and no longer grew on 93% methylated pectin as a carbon source. Curiously, the pme mutant, which had no detectable PG activity on highly methylated pectin, was just as virulent as the wild-type strain on tomato, eggplant (aubergine), and tobacco. Since PG activity is required for full virulence, this result suggests that the pectin in these particular hosts may not be highly methylated, or that the breakdown of highly methylated pectin is not a significant factor in the disease process in general. A positive response regulator of PG production called PehR was not required for wild-type Pme production. However...

‣ Correlation of Pectin Methylesterase Activity in Root Caps of Pea with Root Border Cell Separation.

Stephenson, M. B.; Hawes, M. C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1994 Português
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We tested predictions of the hypothesis that pectin methylesterase in the root cap plays a role in cell wall solubilization leading to separation of root border cells from the root tip. Root cap pectin methylesterase activity was detected only in species that release large numbers of border cells daily. In pea (Pisum sativum) root caps, enzyme activity is correlated with border cell separation during development: 6-fold more activity occurs during border cell separation than after cell separation is complete. Higher levels of enzyme activity are restored by experimental induction of border cell separation. A corresponding increase in transcription of a gene encoding root cap pectin methylesterase precedes the increase in enzyme activity. A dramatic increase in the level of soluble, de-esterified pectin in the root tip also is correlated with pectin methylesterase activity during border cell development. This increase in acidic, de-esterified pectin during development occurs in parallel with a decrease in cell wall/apoplastic pH of cells in the periphery of the root cap.

‣ Isolation and characterization of an extracellular glycosylated protein complex from Clostridium thermosaccharolyticum with pectin methylesterase and polygalacturonate hydrolase activity.

Van Rijssel, M; Gerwig, G J; Hansen, T A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1993 Português
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An extracellular protein complex was isolated from the supernatant of a pectin-limited continuous culture of Clostridium thermosaccharolyticum Haren. The complex possessed both pectin methylesterase (EC 3.1.1.11) and exo-poly-alpha-galacturonate hydrolase (EC 3.2.1.82) activity and produced digalacturonate from the nonreducing end of the pectin chain. The protein consisted of 230- and 25-kDa subunits. The large subunit contained 10% (wt/wt) sugars (N-acetylgalactosamine and galactose). Under physiological conditions both activities acted in a coordinated manner: the ratio between methanol and digalacturonate released during degradation was constant and equal to the degree of esterification of the pectin used. Prolonged incubation of the enzyme with pectin led to a nondialyzable fraction that was enriched in neutral sugars, such as arabinose, rhamnose, and galactose; the high rhamnose/galacturonic acid ratio was indicative of hairy region-like structures. The smallest substrate utilized by the hydrolase was a tetragalacturonate. Vmax with oligogalacturonates increased with increasing chain length. The Km and Vmax for the polygalacturonate hydrolase with citrus pectate as a substrate were 0.8 g liter-1 and 180 mumol min-1 mg of protein-1...

‣ Pepper pectin methylesterase inhibitor protein CaPMEI1 is required for antifungal activity, basal disease resistance and abiotic stress tolerance

An, Soo Hyun; Sohn, Kee Hoon; Choi, Hyong Woo; Hwang, In Sun; Lee, Sung Chul; Hwang, Byung Kook
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Português
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Pectin is one of the main components of the plant cell wall that functions as the primary barrier against pathogens. Among the extracellular pectinolytic enzymes, pectin methylesterase (PME) demethylesterifies pectin, which is secreted into the cell wall in a highly methylesterified form. Here, we isolated and functionally characterized the pepper (Capsicum annuum L.) gene CaPMEI1, which encodes a pectin methylesterase inhibitor protein (PMEI), in pepper leaves infected by Xanthomonascampestris pv. vesicatoria (Xcv). CaPMEI1 transcripts are localized in the xylem of vascular bundles in leaf tissues, and pathogens and abiotic stresses can induce differential expression of this gene. Purified recombinant CaPMEI1 protein not only inhibits PME, but also exhibits antifungal activity against some plant pathogenic fungi. Virus-induced gene silencing of CaPMEI1 in pepper confers enhanced susceptibility to Xcv, accompanied by suppressed expression of some defense-related genes. Transgenic ArabidopsisCaPMEI1-overexpression lines exhibit enhanced resistance to Pseudomonas syringae pv. tomato, mannitol and methyl viologen, but not to the biotrophic pathogen Hyaloperonospora parasitica. Together, these results suggest that CaPMEI1, an antifungal protein...

‣ Pectin Methylesterase and Pectin Remodelling Differ in the Fibre Walls of Two Gossypium Species with Very Different Fibre Properties

Liu, Qinxiang; Talbot, Mark; Llewellyn, Danny J.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 05/06/2013 Português
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Pectin, a major component of the primary cell walls of dicot plants, is synthesized in Golgi, secreted into the wall as methylesters and subsequently de-esterified by pectin methylesterase (PME). Pectin remodelling by PMEs is known to be important in regulating cell expansion in plants, but has been poorly studied in cotton. In this study, genome-wide analysis showed that PMEs are a large multi-gene family (81 genes) in diploid cotton (Gossypium raimondii), an expansion over the 66 in Arabidopsis and suggests the evolution of new functions in cotton. Relatively few PME genes are expressed highly in fibres based on EST abundance and the five most abundant in fibres were cloned and sequenced from two cotton species. Their significant sequence differences and their stage-specific expression in fibres within a species suggest sub-specialisation during fibre development. We determined the transcript abundance of the five fibre PMEs, total PME enzyme activity, pectin content and extent of de-methylesterification of the pectin in fibre walls of the two cotton species over the first 25–30 days of fibre growth. There was a higher transcript abundance of fibre-PMEs and a higher total PME enzyme activity in G. barbadense (Gb) than in G. hirsutum (Gh) fibres...

‣ Pectin methylesterase activity determined by different methods and thermal inactivation of exogenous pme in mango juice

Fonte: Editora da Universidade Federal de Lavras Publicador: Editora da Universidade Federal de Lavras
Tipo: Artigo de Revista Científica Formato: text/html
Português
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59.261665%
Pectin methylesterase (PME) hydrolyzes methyl ester groups in pectin chains to form carboxylic groups, releasing methanol and H3O+. The aim of this study was to determine PME activity in samples of pectinases by UV-VIS spectroscopy, to measure the acid and methanol produced in the reaction of pectin with pectinase and to verify the thermal inactivation of exogenous PME in mango juice. The activity of PME in samples of pectinase was determined by potentiometry, UV-VIS spectroscopy, and by the action of alcohol oxidase. The reaction showed greater activity at pH 4.0 to 4.5 and at a temperature of 45° C. PME activity determined by UV-VIS spectroscopy with bromophenol blue indicator showed a good correlation with the activity determined by potentiometry and with alcohol oxidase. The results showed that bromophenol blue indicators can be used to determine PME activity in samples of pectinases where the optimum pH is located in the acidic range. The thermal inactivation of exogenous PME in mango juice occurred at 75° C for 20 min of exposure.

‣ Pectin methylesterase, metal ions and plant cell-wall extension. Hydrolysis of pectin by plant cell-wall pectin methylesterase.

Nari, J; Noat, G; Ricard, J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/10/1991 Português
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The hydrolysis of p-nitrophenyl acetate catalysed by pectin methylesterase is competitively inhibited by pectin and does not require metal ions to occur. The results suggest that the activastion by metal ions may be explained by assuming that they interact with the substrate rather than with the enzyme. With pectin used as substrate, metal ions are required in order to allow the hydrolysis to occur in the presence of pectin methylesterase. This is explained by the existence of 'blocks' of carboxy groups on pectin that may trap enzyme molecules and thus prevent the enzyme reaction occurring. Metal ions may interact with these negatively charged groups, thus allowing the enzyme to interact with the ester bonds to be cleaved. At high concentrations, however, metal ions inhibit the enzyme reaction. This is again understandable on the basis of the view that some carboxy groups must be adjacent to the ester bond to be cleaved in order to allow the reaction to proceed. Indeed, if these groups are blocked by metal ions, the enzyme reaction cannot occur, and this is the reason for the apparent inhibition of the reaction by high concentrations of metal ions. Methylene Blue, which may be bound to pectin, may replace metal ions in the 'activation' and 'inhibition' of the enzyme reaction. A kinetic model based on these results has been proposed and fits the kinetic data very well. All the available results favour the view that metal ions do not affect the reaction through a direct interaction with enzyme...

‣ Pectin methylesterase, metal ions and plant cell-wall extension. The role of metal ions in plant cell-wall extension.

Moustacas, A M; Nari, J; Borel, M; Noat, G; Ricard, J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/10/1991 Português
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The study of pectin methylesterase and wall-loosening enzyme activities in situ, as well as the estimation of the electrostatic potential of the cell wall, suggest a coherent picture of the role played by metal ions and pH in cell-wall extension. Cell-wall growth brings about a decrease of local proton concentration because the electrostatic potential difference (delta psi) of the wall decreases. This in turn activates pectin methylesterase, which restores the initial delta psi value. This process is amplified by the attraction of metal ions in the polyanionic cell-wall matrix. The amplification process is basically due to the release of enzyme molecules that were initially bound to 'blocks' of carboxy groups. This increase of metal-ion concentration also results in the activation of wall-loosening enzymes. Moreover, the apparent 'inhibition' of pectin methylesterase by high salt concentrations may be considered as a device which prevents the electrostatic potential from becoming too high.

‣ The Pectin Methylesterase Gene Complement of Phytophthora sojae: Structural and Functional Analyses, and the Evolutionary Relationships with Its Oomycete Homologs

Horowitz, Brent B.; Ospina-Giraldo, Manuel D.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 06/11/2015 Português
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Phytophthora sojae is an oomycete pathogen that causes the disease known as root and stem rot in soybean plants, frequently leading to massive economic damage. Additionally, P. sojae is increasingly being utilized as a model for phytopathogenic oomycete research. Despite the economic and scientific importance of P. sojae, the mechanism by which it penetrates the host roots is not yet fully understood. It has been found that oomycetes are not capable of penetrating the cell wall solely through mechanical force, suggesting that alternative factors facilitate breakdown of the host cell wall. Pectin methylesterases have been suggested to be important for Phytophthora pathogenicity, but no data exist on their role in the P. sojae infection process. We have scanned the newly revised version of the annotated P. sojae genome for the presence of putative pectin methylesterases genes and conducted a sequence analysis of all gene models found. We also searched for potential regulatory motifs in the promoter region of the proposed P. sojae models, and investigated the gene expression levels throughout the early course of infection on soybean plants. We found that P. sojae contains a large repertoire of pectin methylesterase-coding genes and that most of these genes display similar motifs in the promoter region...