Oxidoreductase enzymes liberated by plant roots and their effects on soil humic material

Gramss, G.; Voigt, Kerstin; Kirsche, Brigitta

doi:10.1016/s0045-6535(98)00369-5

Cited by 103 publications

(39 citation statements)

References 37 publications

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“…Accordingly, Mn(II) starvation in the treatments 1a, 1b, and 4b led to the lowest outcome in azodication production (Table 1) but possibly, too, in a drop of enzyme release that is stimulated by mineral fertilizing [37]. Contributions of root-exuded laccase (E 0 = 0.4 V) and MMO (E 0 = 0.26 V) traces as active oxygen independent enzymes may solely depend on proper redox mediator systems to overcome their deficit in redox potential.…”

Section: Interaction Of Catalystsmentioning

confidence: 94%

“…The green solutions bleached within 7-30 h to gradually express red color tones after 24-60 h in all treatments of white mustard (1a-4b) and in oilseed rape. Alfalfa plants known to surpass root exuded PO activities of white mustard up to 167-182 times both in axenic and natural soil cultures [15,37] formed red derivatives peaking at A 543 in a superior quantity without a notable phase of preceding A 420 intermediates (Figure 2). The position of absorbance peaks in red culture fluids point to the presence of ABTS 2+ in the A 515 to A 520 range [56].…”

Section: Oxidation Of Abts By Gnotobiotic Plant Culturesmentioning

confidence: 99%

“…Class (iii) peroxidases could thus be leached from roots of cotton, wheat, cress, tomato, water hyacinth, French bean, rice [33,35] and other plants [15,30,36]. Taken with the chromogen guaiacol at pH 7.0, alfalfa plants but not oilseed rape surpassed the root exuded PO activities of white mustard 167-182 times both in axenic and natural soil cultures [15,37]. Contemporarily, sterile root effluents of herbs contained little, if any, H 2 O 2 , or its precursor O 2…”

Section: Introductionmentioning

confidence: 99%

“…Relative to unplanted controls and without H 2 O 2 amendments, the water solubility of HS rose to 115-156%. The concentrations of their phenolic OH groups dropped by 53-79% (r = 0.815, p ≥ 0.67) in PO releasing plants, and by 28-34% in plants with no extractable PO exudates, to copy the reactions obtained in fungal cultures [37].…”

Section: Introductionmentioning

confidence: 99%

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Formation of the Azodication (ABTS2+) from ABTS [2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulphonate)] in Sterile Plant Cultures: Root–Exuded Oxidoreductases Contribute to Rhizosphere Priming

Gramss

2018

Soil Systems

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Abstract:Rhizosphere priming by terrestrial plants comprises increased or repressed efflux of CO 2 and N from soil organic matter (SOM), decaying under the impact of temperature, moisture, and the composition of rhizodeposits. Contemporarily, increases in water solubility vs. losses in molecular size, aromaticity, and the content in phenolic OH groups denote the degradation of SOM in planted soil. Root peroxidases (POs) and 'polyphenoloxidases' are surmised to contribute to these effects, however, final evidence for this is lacking. Therefore, seedlings of white mustard, alfalfa, and oilseed rape with wide spans in PO release were grown in hydroponic cultures at variable levels of Cu/Fe/Mn as Fenton metals, but also under P and Fe starvation to stimulate the release of carboxylic acids that form catalytic Mn 3+ chelants from Mn 2+ and MnO 2 . The shortage in active oxygen as a cosubstrate of POs delayed the immediate oxidation of 2,2 -azinobis-(3-ethylbenzothiazoline-6-sulphonate) (ABTS) supplements to the green ABTS •+ by PO/H 2 O 2 , the possible formation of Mn 3+ via PO catalyzed aryloxy radicals from root-released phenolics, and of HO • by metal cations in H 2 O 2 dependent Fenton-like reactions. Enhanced by exuded and external malate, O 2 independent MnO 2 supplements in some treatments formed ABTS •+ spontaneously. The culture fluids then turned red in all treatments within 24-60 h by the formation of azodication (ABTS 2+ ) derivatives in a second plant initiated oxidation step that is known to be catalyzed by substrate radicals. It is concluded that plants initiate oxidative activities that contribute to rhizosphere priming in an environment of oxidoreductase and carboxylate exudates, the indicated presence of mediating substrate radicals, and the cations and (hydr)oxides of transition metals. Pathways of H 2 O 2 production upon the degradation of carboxylates and by the POs themselves are indicated.

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Section: Interaction Of Catalystsmentioning

confidence: 94%

Section: Oxidation Of Abts By Gnotobiotic Plant Culturesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Formation of the Azodication (ABTS2+) from ABTS [2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulphonate)] in Sterile Plant Cultures: Root–Exuded Oxidoreductases Contribute to Rhizosphere Priming

Gramss

2018

Soil Systems

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“…It was indicated that PW inoculation was the main reason increased the activity of polyphenol oxidase. And the enhanced polyphenol oxidase activity in RP treatment may contribute to the increasing dissipation of pyrene as polyphenol oxidase can catalyze the degradation and transformation of aromatic compounds (Gramss et al, 1999;Liu et al, 2004). Thus, microbial degradation appears to be the most important approach during the remediation process and plant growth will in turn enhance the microbial growth of both native and introduced strains.…”

Section: Effect Of Bioaugmentation On Soil Enzyme Activitiesmentioning

confidence: 99%

Mineralization of pyrene induced by interaction between Ochrobactrum sp. PW and ryegrass in spiked soil

Liu

Wei

Qiao

et al. 2016

Ecotoxicology and Environmental Safety

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a b s t r a c tThis study was conducted to investigate the capability of pyrene-degrading bacterium Ochrobactrum sp. PW and ryegrass (Lolium multiflorum) grown alone and in combination on the degradation of pyrene in soil. After 60 days of ryegrass growth, plant biomass, pyrene-degrading microbial mass, soil enzyme activity (catalase activity and polyphenol oxidase activity) and residual concentration of pyrene in soils were determined. Higher dissipation rates were observed in PW inoculation treatments: ryegrassþ PW rhizosphere soil (RP-r) and ryegrassþ PW non-rhizosphere soil (RP-nr), than planting of ryegrass alone, rhizosphere (R-r) or non-rhizosphere (R-nr). The inoculation with PW significantly (p o0.05) increased the dry weight of ryegrass root and shoot, nearly 2.8 and 3.3 times higher than ryegrass treatment. The pyrene-degrading microbial mass indicated that a much larger mass of bacteria, actinobacteria were present in RP treatment. The catalase activity in all different treatments were significantly (p o 0.05) higher than in with treatment R-nr, and the polyphenol oxidase activity was also significantly (p o 0.05) increased by inoculation with PW, leading to enhanced mineralization of pyrene from soil. Our results suggest that adding of PAHs-degrading bacteria to soil can enhance remediation of PAHs contaminated soil, while improving plant growth.

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Genes and Enzymes for In-Planta Phytoremediation of Air, Water and Soil

Schäffner¹,

Messner²,

Langebartels³

et al. 2002

Acta Biotechnol.

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SummaryPlants harbour highly versatile enzymatic machineries to attack and detoxify pollutants. Similarities to the mammalian detoxification led to the coining of the term "green liver" for plant xenobiotic metabolism. Important enzyme classes such as cytochrome P450 monoxygenases, glutathione S-transferases, glycosyltransferases and transporters are involved in both kingdoms. The availability of the first whole plant genome sequence of Arabidopsis thaliana revealed an unforeseen complexity of these enzyme classes. Genetic and biochemical diversity, by far exceeding at least single microorganisms, seems to exist in plants. In agreement with previous investigations at the enzymatic level both terrestrial and aquatic plants possess an enormous potential for phytoremediation of soil, water and air if limitations due to insufficient uptake into plants can be overcome. This is exemplified by the detoxification of herbicides, halogenated phenols and anilines, and formaldehyde by the action of plant enzymes. Two examples are discussed at the biochemical and genetic level. Plants can detoxify airborne formaldehyde by a glutathione-dependent formaldehyde dehydrogenase. Recombinant expression of an Arabidopsis UDP-glucose dependent glucosyltransferase showed activity towards both endogenous and xenobiotic substrates by a single enzyme. Plants frequently do not completely degrade xenobiotics, but rather form conjugated metabolites and "bound" residues. However, these potential contaminants can be easily removed by harvesting. In order to exploit this enormous potential of plants, promising approaches extending their endogenous capacity have been initiated. Transgenic organisms that express heterologous enzymes in order to specifically degrade compounds or to increase the mobility and uptake of recalcitrant xenobiotics are being pursued to make phytoremediation procedures useful in practice.

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Oxidoreductase enzymes liberated by plant roots and their effects on soil humic material

Cited by 103 publications

References 37 publications

Formation of the Azodication (ABTS2+) from ABTS [2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulphonate)] in Sterile Plant Cultures: Root–Exuded Oxidoreductases Contribute to Rhizosphere Priming

Formation of the Azodication (ABTS2+) from ABTS [2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulphonate)] in Sterile Plant Cultures: Root–Exuded Oxidoreductases Contribute to Rhizosphere Priming

Mineralization of pyrene induced by interaction between Ochrobactrum sp. PW and ryegrass in spiked soil

Genes and Enzymes for In-Planta Phytoremediation of Air, Water and Soil

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