Anions Activate the Oxidation of Indoleacetic Acid by Peroxidases from Tomato and Other Sources

Pressey, Russell

doi:10.1104/pp.93.2.798

Cited by 29 publications

(8 citation statements)

References 29 publications

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“…This indicates that ethylene is not involved in the development of the increased IAA-decarboxylation capacity that occurs after excision of green tomato pericarp discs. The differential effects of the AOA/CoC12 and AVG treatments on decarboxylation of IAA are in keeping with observation of Pressey (1990) that AOA, unlike AVG, is a strong inhibitor of peroxidase-mediated IAA oxidation.…”

Section: Resultssupporting

confidence: 76%

Decarboxylative metabolism of [1′-14C]indole-3-acetic acid by tomato pericarp discs during ripening

Catalá

Crozier

Chamarro

1994

Planta

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Abstract. The rate of decarboxylation of [1'-14C]indole-3-acetic acid (IAA) infiltrated into tomato (Lycopersicon esculentum Mill.) pericarp discs was much more rapid in green than in breaker and pink tissues. Studies were carried out in order to determine whether the decarboxylative catabolism occurring in the green pericarp discs was associated with ripening or was a consequence of woundinduced peroxidase activity and/or ethylene production. After a 2-h lag, the decarboxylative capacity of the green pericarp discs increased exponentially during a 24-h incubation period. This increase was accompanied by increases in IAA-oxidase activity in cell-free preparations from the intercellular space and cut surface of the discs. Although higher IAA-oxidase activity was detected in extracts from the tissue residue, which comprises mainly intracellular peroxidases, this activity did not increase during the 24-h incubation period. Analysis of the cellfree preparations by isoelectric focusing revealed the major component in all samples was a highly anionic peroxidase (pI = 3.5) the levels of which did not increase during incubation. However, the intercellular and cut-surface preparations contained additional anionic and cationic peroxidases which increased in parallel with the increases in both the IAA-oxidase activity of the preparations and the decarboxylative capacity of the green pericarp discs from which they were derived. Treatment of green discs with the ethylene-biosynthesis inhibitors aminooxyacetic acid and COC12, inhibited the development of an enhanced capacity to decarboxylate [l'-14C]IAA but the inhibition was not counteracted by exogenous ethylene. Another ethylene-biosynthesis inhibitor, aminoethoxyvinyl glycine, also reduced ethylene levels but did not affect IAA decarboxylation, indicating that the decarboxylation was not a consequence of wound-induced ethylene production. The data obtained thus demonstrate that the enhanced capacity to decarAbbreviations: AOA = aminooxyacetic acid; ACC = 1-aminocyclopropane-l-carboxylic acid; AVG = aminoethoxyvinyl glycine; IAA = indole-3-acetic acid Correspondence to: J. Chamarro; FAX: 34 (6) 3 93 00 01 boxylate [l'-14C]IAA that develops in green tomato pericarp discs following excision is not associated with ripening but instead is attributable to a wound-induced increase in anionic and cationic peroxidase activity in the intercellular fluid and at the cut surface of the excised tissues.

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Section: Resultssupporting

confidence: 76%

Decarboxylative metabolism of [1′-14C]indole-3-acetic acid by tomato pericarp discs during ripening

Catalá

Crozier

Chamarro

1994

Planta

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“…Enzymatic activity was determined by the change in A 515 due to the oxidation of aminoantipyrine and 3,5-dicloro-2-idroxibenzensulphonic acid. IAA oxidase activity was determined as described in Pressey, 1990. The presence of UV-fluorescent compounds was visualized by photographing detached leaves under UV light (l 5 320 nm) using the ''ImageMaster'' VDS (Pharmacia Biotech).…”

Section: Pathogen Growth and Infectionmentioning

confidence: 99%

Transgenic Expression of a Fungal endo-Polygalacturonase Increases Plant Resistance to Pathogens and Reduces Auxin Sensitivity

et al. 2007

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Polygalacturonases (PGs), enzymes that hydrolyze the homogalacturonan of the plant cell wall, are virulence factors of several phytopathogenic fungi and bacteria. On the other hand, PGs may activate defense responses by releasing oligogalacturonides (OGs) perceived by the plant cell as host-associated molecular patterns. Tobacco (Nicotiana tabacum) and Arabidopsis (Arabidopsis thaliana) plants expressing a fungal PG (PG plants) have a reduced content of homogalacturonan. Here, we show that PG plants are more resistant to microbial pathogens and have constitutively activated defense responses. Interestingly, either in tobacco PG or wild-type plants treated with OGs, resistance to fungal infection is suppressed by exogenous auxin, whereas sensitivity to auxin of PG plants is reduced in different bioassays. The altered plant defense responses and auxin sensitivity in PG plants may reflect an increased accumulation of OGs and subsequent antagonism of auxin action. Alternatively, it may be a consequence of perturbations of cellular physiology and elevated defense status as a result of altered cell wall architecture.

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“…Galactaric acid activated the oxidation of IAA by tomato peroxidase in the same manner as numerous other polycarboxylic acids (13). A threshold concentration of about 0.3 mM galactaric acid was required, but higher concentrations of the acid increased the rate of oxidation sharply (Fig.…”

Section: Activation Of Iaa Oxidationmentioning

confidence: 72%

“…The reaction mixture consisted of 0.2 mL of 0.1 M sodium acetate, pH 4.0, 0.3 mL of 1 mm Mn2 , 0.2 mL of 1 mM dichlorophenol, 0.3 mL of 1 mm IAA, and 0.1 mL of appropriately diluted tomato peroxidase (13). After 15 min at 30C, 2 mL of Salkowski reagent (8) was added.…”

Section: Iaa Oxidase Assaymentioning

confidence: 99%

Oxidized Oligogalacturonides Activate the Oxidation of Indoleacetic Acid by Peroxidase

Pressey

1991

Plant Physiol.

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Partial hydrolysis of polygalacturonic acid with a purified a-1,4-endopolygalacturonase yielded oligogalacturonides and trace amounts of a series of modified oligogalacturonides. Three of the minor products were isolated and identified as oxidized oligogalacturonides possessing termini of galactaric acid. Oxidation of indole-3-acetic acid by peroxidases was activated by oxidized oligogalacturonides but not by normal analogs.Oligosaccharides composed of 1,4-linked a-D-galacturonic acid residues (oligogalacturonides) have been included in a possible new class of regulatory molecules consisting of plant cell wall fragments that have been named oligosaccharins (1).They act as elicitors for the accumulation ofproteinase inhibitors in tomato leaves (3) and of phytoalexins in several plants (6, 1 1). Evidence has been presented that oligogalacturonides of a specific Dp' regulate organ development in tobacco explants (14) and induce ethylene production in fruit tissues (5). There has not been an explanation of how these pectic fragments can induce such a variety of responses in plants. A clue to their mode of action may lie in a recent observation that certain anions are extraordinary activators of the oxidation of IAA by plant peroxidases (1 3). Mixtures of oligogalacturonides prepared by the controlled enzymic fragmentation of polygalacturonic acid also activate the oxidation of IAA, and this study deals with identification of the active components. MATERIALS AND METHODS Purification of PolygalacturonasesEndo-and exopolygalacturonases in Pectinase from Aspergillus niger (Sigma) were separated by chromatography on a column of Q-Sepharose (Pharmacia) and purified by fast protein liquid chromatography on a column of Mono Q (Pharmacia). Details of the purification and characterization of the enzymes will be published separately. A unit of exo-or endopolygalacturonase is defined as that amount liberating ,umol of reducing groups from polygalacturonic acid/min at 300C. ' Abbreviations: Dp, degree of polymerization; HPAE-PAD, high performance anion-exchange chromatography with pulsed amperometric detection; KnA, 1000 nanoamp. Preparation of Polygalacturonic Acid HydrolyzateTen grams of polygalacturonic acid (P3889, Sigma) was dissolved in 1 L water, adjusted to pH 4.5, and warmed to 30C. Endopolygalacturonase (280 units) was added to the solution and incubated at 30TC for 1 h. The enzyme was then inactivated by heating the solution at 1000C for 5 min and the small amount of precipitate was removed by centrifugation. The oligogalacturonides in the solution were precipitated by addition of 5 g CaCl2 and a volume of 95% ethanol at pH 6.0. The precipitate was collected by centrifugation, washed with 50% ethanol, and dried under vacuum. Analysis of Oligogalacturonides by High Performance Anion-Exchange ChromatographyOligogalacturonides were analyzed by HPAE-PAD on a CarboPac PAI column in a Dionex system. Elution was conducted with 0.19 M sodium acetate in 65 mm NaOH for 5 min and then with a linear gradient of 0.19 to...

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Anions Activate the Oxidation of Indoleacetic Acid by Peroxidases from Tomato and Other Sources

Cited by 29 publications

References 29 publications

Decarboxylative metabolism of [1′-14C]indole-3-acetic acid by tomato pericarp discs during ripening

Decarboxylative metabolism of [1′-14C]indole-3-acetic acid by tomato pericarp discs during ripening

Transgenic Expression of a Fungal endo-Polygalacturonase Increases Plant Resistance to Pathogens and Reduces Auxin Sensitivity

Oxidized Oligogalacturonides Activate the Oxidation of Indoleacetic Acid by Peroxidase

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