Developmental variation of cell wall degrading enzymes from cucumber (Cucumis sativus) fruit tissues

1989 ◽  
Vol 67 (3) ◽  
pp. 817-821 ◽  
Author(s):  
A. Raymond Miller ◽  
Joseph P. Dalmasso ◽  
Dale W. Kretchman
Keyword(s):  
Cell Wall ◽  
Cucumis Sativus ◽  
Pectin Methylesterase ◽  
Lag Phase ◽  
Cell Wall Degrading Enzymes ◽  
Cucumis Sativus L ◽  
Developmental Variation ◽  
Phase 0 ◽  
Sigmoidal Growth ◽  
Increased Activity

Variation of cell wall degrading enzyme activities and tissue firmness from the petal senescence to overripe stages of fruit development was studied in greenhouse-grown cucumbers (Cucumis sativus L. cv. Heinz 3534). Cucumbers exhibited a typical sigmoidal growth curve with a short lag phase (0–8 days after pollination) and extended log phase (8–28 days) followed by a stationary phase. Mesocarp firmness decreased between 10 and 20 days after pollination, then increased until 32 days after pollination. This decrease of mesocarp firmness was accompanied by increased activity of cellulase (3.5-fold), polygalacturonase (20-fold), pectin methylesterase (4-fold), and xylanase (9-fold). By contrast, carpel tissue firmness declined from 8–20 days after pollination, and remained low until 32 days after pollination. Only polygalacturonase and xylanase activities exhibited significant increases (5- and 6-fold, respectively) during softening of this tissue. Further, these peaks of enzyme activity in the carpel occurred 10 days before the corresponding peaks in the mesocarp. These data suggest that mesocarp and carpel tissues of cucumber soften by similar, but not identical mechanisms.

scholarly journals High-CO2 Treatment Prolongs the Postharvest Shelf Life of Strawberry Fruits by Reducing Decay and Cell Wall Degradation

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1649
Author(s):  
Hyang-Lan Eum ◽  
Seung-Hyun Han ◽  
Eun-Jin Lee
Keyword(s):  
Cell Wall ◽  
Shelf Life ◽  
Physiological Mechanism ◽  
Pectate Lyase ◽  
Pectin Methylesterase ◽  
Cell Wall Degradation ◽  
Cell Wall Degrading Enzymes ◽  
High Co2 ◽  
Genes Encoding ◽  
Co2 Treatment

Improved methods are needed to extend the shelf life of strawberry fruits. The objective of this study was to determine the postharvest physiological mechanism of high-CO2 treatment in strawberries. Harvested strawberries were stored at 10 °C after 3 h of exposure to a treatment with 30% CO2 or air. Pectin and gene expression levels related to cell wall degradation were measured to assess the high-CO2 effects on the cell wall and lipid metabolism. Strawberries subjected to high-CO2 treatment presented higher pectin content and firmness and lower decay than those of control fruits. Genes encoding cell wall-degrading enzymes (pectin methylesterase, polygalacturonase, and pectate lyase) were downregulated after high-CO2 treatment. High-CO2 induced the expression of oligogalacturonides, thereby conferring defense against Botrytis cinerea in strawberry fruits, and lowering the decay incidence at seven days after its inoculation. Our findings suggest that high-CO2 treatment can maintain strawberry quality by reducing decay and cell wall degradation.

scholarly journals Inhibitory Effects of CaCl2 and Pectin Methylesterase on Fruit Softening of Raspberry during Cold Storage

Horticulturae ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Ran Yan ◽  
Cong Han ◽  
Maorun Fu ◽  
Wenxiao Jiao ◽  
Weihao Wang
Keyword(s):  
Cell Wall ◽  
Cold Storage ◽  
Middle Lamella ◽  
Free Water ◽  
Pectin Methylesterase ◽  
Wall Structure ◽  
Rapid Decline ◽  
Fruit Softening ◽  
Cell Wall Degrading Enzymes

Quality of raspberry fruit experiences a rapid decline after harvest due to its vulnerable texture and high moisture content. Application of calcium chloride (CaCl2) combined with pectin methylesterase (PME) is efficient in delaying fruit softening. In this study, the effects of exogenous CaCl2 alone or in combination with PME on the structure of the cell wall, the molecular properties of pectin, and the amount of free water of raspberry during postharvest storage were investigated. The results showed that CaCl2 combined with PME treatment could maintain fruit firmness and inhibit weight loss. The treatment of CaCl2+PME maintained the cell wall structure via sustaining middle lamella integrity and reducing the activities of cell wall-degrading enzymes, such as polygalacturonase, pectin methylesterase, β-galactosidase, α-L-arabinofuranosidase, and β-xylosidase. In addition, CaCl2+PME treatment could effectively increase the content of chelate-soluble pectin (CSP) and develop a cross-linked structure between Ca2+ and CSP. Moreover, CaCl2+PME treatment was of benefit in maintaining free water content. CaCl2 in combination with PME treatment could be a promising method for inhibiting softening and maintaining the quality of postharvest raspberry during cold storage.

scholarly journals The Necrotrophic Fungus Macrophomina phaseolina Promotes Charcoal Rot Susceptibility in Grain Sorghum Through Induced Host Cell-Wall-Degrading Enzymes

2018 ◽  
Vol 108 (8) ◽  
pp. 948-956 ◽  
Author(s):  
Y. M. A. Y. Bandara ◽  
D. K. Weerasooriya ◽  
S. Liu ◽  
C. R. Little
Keyword(s):  
Cell Wall ◽  
Glycosyl Hydrolase ◽  
Pectin Methylesterase ◽  
Macrophomina Phaseolina ◽  
Grain Sorghum ◽  
Cell Wall Degrading Enzymes ◽  
Charcoal Rot ◽  
Degrading Enzymes ◽  
Encoding Genes ◽  
Polygalacturonase Activity

The cell-wall-degrading enzymes (CWDE) secreted by necrotrophs are important virulence factors. Although not unequivocally demonstrated, it has been suggested that necrotrophs induce hosts to cooperate in disease development through manipulation of host CWDE. The necrotrophic fungus Macrophomina phaseolina causes charcoal rot disease in Sorghum bicolor. An RNA-seq experiment was conducted to investigate the behavior of sorghum CWDE-encoding genes after M. phaseolina inoculation. Results revealed M. phaseolina’s ability to significantly upregulate pectin methylesterase-, polygalacturonase-, cellulase-, endoglucanase-, and glycosyl hydrolase-encoding genes in a charcoal rot-susceptible sorghum genotype (Tx7000) but not in a resistant genotype (SC599). For functional validation, crude enzyme mixtures were extracted from M. phaseolina- and mock-inoculated charcoal-rot-resistant (SC599 and SC35) and -susceptible (Tx7000 and BTx3042) sorghum genotype stalks. A gel diffusion assay (pectin substrate) revealed significantly increased pectin methylesterase activity in M. phaseolina-inoculated Tx7000 and BTx3042. Polygalacturonase activity was determined using a ruthenium red absorbance assay (535 nm). Significantly increased polygalacturonase activity was observed in two susceptible genotypes after M. phaseolina inoculation. The activity of cellulose-degrading enzymes was determined using a 2-cyanoacetamide fluorimetric assay (excitation and emission maxima at 331 and 383 nm, respectively). The assay revealed significantly increased cellulose-degrading enzyme activity in M. phaseolina-inoculated Tx7000 and BTx3042. These findings revealed M. phaseolina’s ability to promote charcoal rot susceptibility in grain sorghum through induced host CWDE.

Factors That Influence the Yield and Viability of Cucumber (Cucumis sativus L) Cotyledon Protoplasts

1990 ◽  
Vol 38 (2) ◽  
pp. 169 ◽  
Author(s):  
AS Kantharajah ◽  
WA Dodd
Keyword(s):  
Cell Wall ◽  
Cucumis Sativus ◽  
Incubation Time ◽  
Considerable Change ◽  
Isolation Procedure ◽  
Size Class ◽  
Cucumis Sativus L ◽  
Isolation Technique ◽  
Cucumber Seedlings ◽  
A Cell

Protoplasts isolated from cotyledons of aseptically germinated cucumber seedlings were divided into three size classes. The relationships between tissue age, isolation procedure, yield and protoplast size were investigated. During germination and up to an age of 13 days, the percentage of protoplasts in each size class underwent considerable change with a big reduction in percentage of the largest protoplasts in older cotyledons. Protoplast size and yield could also be manipulated by varying the isolation technique. In this context, temperature, incubation time and shaker speed were significant. By selecting tissue of appropriate age and using a carefully selected isolation procedure the percentage of viable cucumber protoplasts with the ability to form a cell wall and divide can be increased considerably.

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

1998 ◽  
Vol 64 (12) ◽  
pp. 4918-4923 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Yanfen Guan ◽  
Caitilyn Allen
Keyword(s):  
Cell Wall ◽  
Bacterial Wilt ◽  
Plant Cell Wall ◽  
Genomic Library ◽  
Response Regulator ◽  
Disease Process ◽  
Pectin Methylesterase ◽  
Wild Type ◽  
Cell Wall Degrading Enzymes

ABSTRACT 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 pmechromosomal 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, a mutant strain lacking PhcA, which is a global regulator of several virulence genes, produced no detectable Pme activity. Thus,pme expression is directly or indirectly regulated by PhcA but not by PehR.

Rhizosphere-competent isolates of streptomycete and non-streptomycete actinomycetes capable of producing cell-wall-degrading enzymes to controlPythium aphanidermatumdamping-off disease of cucumber

2006 ◽  
Vol 84 (2) ◽  
pp. 211-222 ◽  
Author(s):  
Khaled A. El-Tarabily
Keyword(s):  
Cell Wall ◽  
Rhizosphere Soil ◽  
Damping Off ◽  
Cell Wall Degrading Enzymes ◽  
Cucumis Sativus L ◽  
Degrading Enzymes ◽  
Rhizosphere Competence ◽  
Volatile Inhibitors ◽  
Micromonospora Chalcea

Fifty-eight streptomycete and 35 non-streptomycete actinomycetes were isolated from cucumber rhizosphere soil. These isolates were screened for the production of cell-wall-degrading enzymes using mycelial ( Pythium aphanidermatum (Edson) Fitzp.) fragment agar. Eighteen promising isolates were screened for their competence as root colonizers. Eight isolates showing exceptional rhizosphere competence significantly inhibited, in vitro, P. aphanidermatum, the causal agent of postemergence damping-off of cucumber ( Cucumis sativus L.) seedlings. The four most inhibitory isolates ( Actinoplanes philippinensis Couch, Microbispora rosea Nonomura and Ohara, Micromonospora chalcea (Foulerton) Ørskov, and Streptomyces griseoloalbus (Kudrina) Pridham et al.) produced in vitro β-1,3-, β-1,4-, and β-1,6-glucanases and caused lysis of P. aphanidermatum hyphae. None of these produced volatile inhibitors or siderophores. Only S. griseoloalbus produced diffusible inhibitory metabolites, whilst A. philippinensis and Micromonospora chalcea parasitized the oospores of P. aphanidermatum. These four isolates were subsequently tested in the greenhouse, individually or as a mixture, for their ability to suppress damping-off of cucumber seedlings in soil with or without cellulose amendment. The treatment, which included all four isolates in soil amended with cellulose, was significantly superior to all other treatments in suppressing damping-off and was nearly as good as the metalaxyl treatment. Results show that there is a potential to use a mixture of antagonistic rhizosphere-competent actinomycetes along with cellulose amendment rather than fungicides for the field management of this disease. This is the first study that has involved the screening of rhizosphere-competent non-streptomycete actinomycetes capable of producing cell-wall-degrading enzymes, for the management of Pythium diseases.

scholarly journals Pythium sulcatum and P. ultimum as causal agents of cavity spot disease of carrots in Egypt

2004 ◽  
Vol 84 (2) ◽  
pp. 607-614 ◽  
Author(s):  
K. A. El-Tarabily ◽  
M. A. Abouzeid ◽  
G. E. ST. J. Hardy ◽  
K. Sivasithamparam
Keyword(s):  
Cell Wall ◽  
Nile Delta ◽  
Pectate Lyase ◽  
Pectin Methylesterase ◽  
First Record ◽  
Cell Wall Degrading Enzymes ◽  
Spot Disease ◽  
Degrading Enzymes ◽  
Cavity Spot ◽  
Pathogenicity Tests

In a survey of carrot diseases of the Nile delta region of northern Egypt, Pythium sulcatum (Pratt and Mitchell) and P. ultimum (Trow) were isolated from 74 and 26%, respectively, of carrot roots showing cavity spot disease. In laboratory and glasshouse pathogenicity tests, P. sulcatum caused significantly (P < 0.05) more severe damage than P. ultimum. The greater level of pathogenicity of P. sulcatum was associated with its ability to produce a wider array of cell-wall-degrading enzymes with significantly (P < 0.05) higher enzymatic activities compared to P. ultimum. Polygalacturonase, pectin lyase, pectate lyase and cellulase were detected in cavity spot lesions induced by both P. sulcatum and P. ultimum. Pectin methylesterase was detected in tissues invaded by P. sulcatum and not by P. ultimum. This is the first record of cavity spot disease of carrots in Egypt and indicates P. sulcatum and P. ultimum as the causal agents of this disease in the region surveyed. Key words: Carrots, cavity spot, cell-wall-degrading enzymes, Egypt, Pythium

scholarly journals Pawpaw [Asimina triloba (L.) Dunal] Fruit Ripening. II. Activity of Selected Cell-wall Degrading Enzymes

2005 ◽  
Vol 130 (4) ◽  
pp. 643-648 ◽  
Author(s):  
Rumphan Koslanund ◽  
Douglas D. Archbold ◽  
Kirk W. Pomper
Keyword(s):  
Cell Wall ◽  
Pectin Methylesterase ◽  
Relative Increase ◽  
Fruit Firmness ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Asimina Triloba ◽  
Early Ripening ◽  
Cell Wall Disassembly ◽  
Tissue Prints

Pawpaw fruit were harvested at the advent of the ripening process and were ripened at room temperature. Based on fruit firmness and respiration and ethylene production rates at harvest and during ripening, fruit were classified into one of four categories: preripening (no to very slight loss of firmness; preclimacteric), early ripening (some softening; increasing rates of ethylene and CO2 production), mid-ripening (soft; at or just past climacteric), and late ripening (very soft; postclimacteric). The activities of the cell-wall degrading enzymes polygalacturonase (PG), endo-(1→4)ß-D-glucanase (EGase), and endo-ß-1,4-mannanase (MAN) were low in the preripening and early ripening stages, increased dramatically by mid-ripening coincident with the respiratory and ethylene climacterics, and decreased at late ripening. However, pectin methylesterase (PME) activity per milligram protein was highest at the green stage when the fruit firmness was high and decreased as ripening progressed. Tissue prints indicated both EGase and MAN increased as ripening proceeded. The EGase activity was evident near the seeds and the surface of the fruit at preripening and eventually spread throughout, while MAN activity was evident near the fruit surface at preripening and was progressively expressed throughout the flesh as fruit ripened. The greatest decline in fruit firmness occurred between pre- and early ripening, before the peak activities of PG, EGase, and MAN, although MAN exhibited the greatest relative increase of the three enzymes in this period. The data suggest that PME may act first to demethylate polygalacturonate and may be followed by the action of the other enzymes resulting in cell wall disassembly and fruit softening in pawpaw.

Sign in / Sign up

Export Citation Format

Share Document