Assay methods for pectic enzymes

Collmer, Alan; Ried, Jeffrey L.; Mount, Mark S.

doi:10.1016/0076-6879(88)61037-8

Cited by 272 publications

(181 citation statements)

References 32 publications

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“…At the same time, another study reported that PL activity in banana could also be measured at 540 nm (Marin-Rodriguez et al 2003). The PL enzyme reaction product combined with TBA generates colored compounds which have an absorption peak at 545-550 nm and we could detect the PL activity within this wavelength range (Collmer et al 1988). However, in this study it is reported for the first time that the absorption diagram of PL in strawberry fruit showed an absorption peak at 500 nm.…”

Section: Discussionmentioning

confidence: 39%

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Comparative analysis of pectate lyase in relation to softening in strawberry fruits

Zhou¹,

Li²,

Zhao³

2016

Can. J. Plant Sci.

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Strawberry fruits are perishable due to fruit softening occurring during storage and marketing, but the mechanism by which this occurs is not clear. In this study, the possible mechanism of softening is explored by comparative studies on the changes of fruit firmness, pectate lyase (PL) activities, and relative expression levels of PL genes between two strawberry cultivars. The results indicate that a method for the determination of PL activity in the strawberry fruit was established. The activity of PL was at a low level in the small green fruit to white fruit stage, and maintained at a high level in the ripening and softening stage. The PL gene was specifically expressed in fruit and mainly in the ripening stage. PL expressions were closely correlated with PL activities, and negatively related with the changes in flesh firmness. The full-length cDNA of PL genes from the two cultivars was cloned using the RACE method. Amino acid residues of C terminal sequences of the PL proteins from different species showed significant variations. Those results suggested that the differences in PL activity, gene sequence, and gene expression patterns may lead to the different roles of PL in different fruit textures of strawberries during ripening and softening.Key words: fruit ripening and softening, pectate lyase, strawberry.Résumé : La fraise est un fruit périssable parce que la baie ramollit pendant l'entreposage et la vente, mais on ne sait pas exactement quel mécanisme est à l'origine de ce phénomène. Les auteurs se sont efforcés de le préciser en comparant les changements qui surviennent au niveau de la fermeté du fruit, de l'activité de la pectate lyase (PL) et de l'expression relative des gènes PL chez deux cultivars de fraisier. Les résultats ont permis d'établir une méthode pour jauger l'activité de la PL chez la fraise. La PL est peu active dans les petites baies vertes, jusqu'au stade du fruit blanc, après quoi elle reste très active pendant le mûrissement et le ramollissement. Le gène PL s'exprime spécifiquement chez le fruit et surtout pendant le mûrissement. L'expression du gène PL est étroitement corrélée à l'activité de la PL et négativement reliée aux changements de fermeté de la chair. Les auteurs ont cloné l'ADNc complet des gènes PL des deux cultivars par la technique RACE. Les résidus des acides aminés de la séquence C finale des protéines PL varient significativement entre les deux variétés. Ces résultats donnent à penser que les écarts au niveau de l'activité de la PL, de la séquence génétique et de l'expression des gènes pourraient expliquer le rôle variable de la PL dans les diverses textures observées chez la fraise pendant le mûrissement et le ramollissement. [Traduit par la Rédaction] Mots-clés : fraise, pectate lyase, mûrissement, ramollissement du fruit.

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Section: Discussionmentioning

confidence: 39%

“…Sequence (5′-3′) cysteine-HCl + 1% Triton X-100 0.399 0.240 0.075 (Collmer et al 1988;Burns 1991). On account of determining the influence of calcium ions on strawberry PL activity, we supplemented different concentration of CaCl 2 into the reaction solution.…”

Section: Symbolmentioning

confidence: 99%

Comparative analysis of pectate lyase in relation to softening in strawberry fruits

Zhou¹,

Li²,

Zhao³

2016

Can. J. Plant Sci.

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“…The isolates were grown on different indicator media including cellulase activity indicator medium (LB medium with 0.5% (w/v) carboxylmethylcellulose and 1.5% agar (w/v) (Farkas et al 1985), xylanase activity indicator medium (LB medium containing 0.5% (w/v) oat spelt xylan and 1.5% agar (w/v) (Farkas et al 1985), amylase activity indicator medium (LB medium containing 1.0% (w/v) starch and 1.5% agar (w/v) (Claus 1988), protease activity indicator medium (LB medium containing 1.0% (w/v) skim milk and 1.5% agar (w/v) Claus (1988), lipase activity indicator medium (LB medium containing 1.0% tricaprylin (v/v) and 1.5% agar (w/v) (Lusty and Doudoroff 1966), esterase activity indicator medium (LB medium containing 1.0% tributyrin (v/v) and 1.5% agar (w/v) (Lusty and Doudoroff 1966), pectinase activity indicator medium (LB medium containing 0.5% polygalaturonate (v/v) and 1.5% agar (w/v) (Collmer et al 1988). Bacterial cultures were incubated at 308C for 48 h. A clearing zones in the medium indicated positive enzyme activity were recorded.…”

Section: Exoenzyme Activity Testsmentioning

confidence: 99%

Isolation and characterization of endophytic bacteria fromPlectranthus tenuiflorusmedicinal plant in Saudi Arabia desert and their antimicrobial activities

El-Deeb

Fayez

Gherbawy

2013

Journal of Plant Interactions

119

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The diversity and beneficial characteristics of endophytic microorganisms have been studied in Plectranthus tenuiflorus medicinal plant. However, information regarding naturally occurring P. tenuiflorus plant associated endophytes among different organs of host is limited. Endophytic bacteria were isolated from root, stem, and leaves of P. tenuiflorus plant. Among 28 endophytic bacterial isolates from different organs of P. tenuiflorus plant, 8 isolates were identified by partial sequencing of their 16S rRNA gene. The isolated endophytic bacteria were Bacillus sp., Bacillus megaterium, Bacillus pumilus, Bacillus licheniformis, Micrococcus luteus, Paenibacillus sp., Pseudomonas sp., and Acinetobacter calcoaceticus. The most isolates that exhibited extracellular enzymatic activity were belonged to the genus Bacillus. Furthermore, Bacillus sp. (HE613660) exhibited the stronger activities in extracellular enzymes such as amylase, esterase, lipase, protease, pectinase, xylanase, and cellulase than other strains. Considerable antimicrobial activities against a panel of human pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Proteus mirabilis, and Candida albicans) were recorded using crude extracts of the collected endophytic strains.

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“…Cellulase activity (EC 3.2.1.21) was determined by measuring the amount of glucose formed from carboxy methyl cellulose [15]. Reactions were conducted for 30 min at 55°C [16]. Specific activity of chitinase, β-1, 3 glucanase and cellulase were expressed as 1 µmol of reducing sugars released.h -1…”

Section: Enzyme and Total Phenol Assaysmentioning

confidence: 99%

Antagonism of Trichoderma spp. against Macrophomina phaseolina: Evaluation of Coiling and Cell Wall Degrading Enzymatic Activities

HP¹

2012

J Plant Pathol Microb

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Materials and Methods Sources of Trichoderma sppSlants of six species of Trichoderma (T. harzianum NBAII Th 1; T. viride NBAII Tv 23; T. virens NBAII Tvs 12; T. koningi MTCC 796; T. pseudokoningi MTCC 2048; T. hamatum NBAII Tha-1.) were obtained either from IARI, New delhi or from MTCC, Chandigarh. One local isolate of T. harzianum was also collected from culture collection of Department of Plant Pathology, Junagadh Agricultural University, Junagadh. Isolation of phytopathogenic fungiMacrophomina phaseolina (Tassi) Goid was used as pathogen. The castor plants showing typical symptoms of root rot were collected AbstractIn vitro potentialities of seven species of Trichoderma were evaluated against phytopathogen Macrophomina phaseolina by dual culture techniques. The maximum growth inhibition of test pathogen was observed by antagonist T. koningi MTCC 796 (T4) (74.3%) followed by T. harzianum NABII Th 1 (T1) (61.4%) at 7 days after inoculation (DAI). Further, mycoparasitism of antagonists were observed upto 14 DAI. Pattern of growth inhibition of test fungus was continued with maximum 14.7% increases in T4 (85.2%) followed by 6.8% elevation in T1 (65.6%) antagonists during 7 to 14 DAI. Microscopic study showed that these two antagonists were capable of overgrowing and degrading M. phaseolina mycelia, coiling around the hyphae with apressoria and hook-like structures. At 14 DAI, T. koningi MTCC 796 completely destroyed the host and sporulated. The specific activities of cell wall degrading enzymes-chitinase, β-1, 3 glucanase, protease and cellulase were tested during different incubation period (24, 48, 72 and 96 h) when Trichoderma spp. grew in presence of pathogen cell wall in synthetic media. The antagonist T. koningi MTCC 796 induced higher chitinase and protease activity at 24 h incubation while β-1, 3 glucanase activities was elevated 1.18 fold during 72 to 96 h. Total phenol was produced significantly higher in culture supernatant of T. koningi MTCC 796 antagonist followed by T. hamatum NBAII Tha 1 and T. harzianum NBAII Th 1 at 48 h incubation. The growth inhibitions of pathogen during antagonism was positively correlated with coiling pattern of antagonists at 14 DAI, and induction of chitinase, β-1, 3 glucanase and total phenol content.

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Assay methods for pectic enzymes

Cited by 272 publications

References 32 publications

Comparative analysis of pectate lyase in relation to softening in strawberry fruits

Comparative analysis of pectate lyase in relation to softening in strawberry fruits

Isolation and characterization of endophytic bacteria fromPlectranthus tenuiflorusmedicinal plant in Saudi Arabia desert and their antimicrobial activities

Antagonism of Trichoderma spp. against Macrophomina phaseolina: Evaluation of Coiling and Cell Wall Degrading Enzymatic Activities

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