Enzyme activities in Appalachian soils: 3. Pyro‐phosphatase

Baligar, V. C.; Wright, Robert J.; Smedley, M. D.

doi:10.1080/00103629109368514

Cited by 7 publications

(4 citation statements)

References 20 publications

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“…Such a mechanism was proposed for explaining observations in the ocean (Colman et al, 2005), and indeed, free pyrophosphatase activity is observed in soils (Baligar et al, 1991;Dick and Tabatabai, 1983); (3) if values similar to the ones expected from equilibrium were accidentally produce by the contrasting effects of lighter oxygen originating from mineralization of microbial and roots organic-P, the heavier oxygen originating from leaf litter and primary mineral dissolution, and the possible enrichment effect of uptake. Although we do not consider the last explanation as very likely, more research is needed to determine which of these three explanations is correct.…”

Section: Interpreting the Measured D 18 O P Valuesmentioning

confidence: 89%

Seasonal variability of soil phosphate stable oxygen isotopes in rainfall manipulation experiments

Angert

Weiner

Mazeh

et al. 2011

Geochimica et Cosmochimica Acta

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Section: Interpreting the Measured D 18 O P Valuesmentioning

confidence: 89%

Seasonal variability of soil phosphate stable oxygen isotopes in rainfall manipulation experiments

Angert

Weiner

Mazeh

et al. 2011

Geochimica et Cosmochimica Acta

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“…They are high in soils with high organic C and organic P contents (Appiah and Thomas 1982;Rojo et al 1990;Baligar et al 1991) and are strongly inhibited by inorganic phosphate (Speir and Ross 1978). Increased activity of acid phosphatase has been found in the roots (Gianinazzi et al 1979;Thiagaragan and Ahmed 1994) and in the rhizosphere (Dodd et al 1987;Tarafdar and Marschner 1994;Joner and Jakobsen 1995) of plants colonized by AM fungi.…”

Section: Discussionmentioning

confidence: 99%

Response of mycorrhizal western red cedar to organic phosphorus sources and benomyl

Cade-Menun¹,

Berch²

1997

Can. J. Bot.

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In some British Columbia forests, western red cedar (Thuja plicntn Donn ex D. Don) grows well in soils with phosphorus (P) mainly in organic form and shows less response to P fertilization than other conifers. It was hypothesized that cedar or their associate arbuscular mycorrhizae could mineralize organic P. In a year-long greenhouse study, 2-year-old cedar trees in Turface were fed every 9 days with one of 1 1 P treatments (in Long Ashton solution): no P; high and low phytic acid (for all treatments, high is 50 mg P . L-', and low is 10 mg P . L-'); high and low ATP; high and low glycerophosphate; high and low pyrophosphate; high and low orthophosphate. Ten mycorrhizal trees were used per treatment; of these, five trees per treatment were treated with the fungicide benomyl, which significantly reduced colonization in only two treatments. Growth was good with high rates of glycerophosphate, ATP, and pyrophosphate; low rates of these compounds resulted in P deficiencies. The trees grew poorly with phytic acid, which may have been adsorbed to the Turface, and which may have cornplexed Ca, Zn, and Cu from the nutrient solution, inducing deficiencies. The P source influenced the activities of rhizosphere acid and alkaline phosphatase, but had no significant effect on phosphodiesterase or pyrophosphatase activity. Use of the fungicide benomyl caused a significant increase in foliar N, either directly from the fungicide or indirectly from effects on N cycling.Resume : Dans certaines for&ts de la Colombie Britannique, le thuya gCant (Thujn plicata Donn ex D. Don) pousse bien dans des sols oh le phosphore (P) prevaut sous forme organique, et rCagit moins bien B la fertilisation P que les autres coniEres. Les auteurs ont formu16 l'hypothkse que le thuya ou ses rnycorhizes arbusculaires (AM) associCes pourraient mineraliser le P organique. Les auteurs ont conduit une expCrience en serre qui a durC une annCe en appliquant les traitements suivants : des thuyas 2gCs de 2 ans ont Ct C cultivCs dans du Turface et nourris tous les 9 jours avec 1 des 11 traitenlents P (en solution de Long Ashton) : sans P; acide phytique ClevC et faible (pour tous les traitenlents, haut signifie 50 mg PIL; faible signifie 10 mg PIL); ATP ClevC et faible; glycerophosphate ClevC et faible; pyrophosphate ClevC et faible; orthophosphate ClevC et faible. Pour chaque traitement elles ont utilisC 10 plants dont 5 plants pour chaque traitement ont requ du fongicide bCnomyl, qui n'a rCduit significativement la mycorhization que dans deux traitements. La croissance a Ct C bonne avec des apports ClevCs en glycCrophosphate, ATP et pyrophosphate; les apports faibles en ces composCs ont entrain6 des dCficiences en P. La croissance a Ct C mediocre en presence d'acide phytique, lequel aurait pu Ctre adsorb6 par le Turface, et avoir complex6 le Ca, le Zn et le Cu de la solution nutritive, conduisant ainsi aux dtficiences. La source de P a influencC les activitCs des phosphatases acides et alcalines de la rhizosphkre, mais est demeurCe sans effet sur les activitC...

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“…The soils we study go through wet–dry cycles that can release enzymes from inside the cells. Indeed, free pyrophosphatase was observed in dried soils that were rewetted in the lab. , The fractionation values we used for organic P mineralization are based on lab studies, which may not be relevant for the processes in soils. Fractionation by microbial and plant uptake may cause an increase in the soil available inorganic δ 18 O p and may result in values that are accidentally close to the ones expected from equilibrium with soil–water. The microbiota might release large amount of P i which was equilibrated inside the cells (Figure ). This flux may result from bacterial cell lysis, from P i excretion by bacteria, or from protozoa that feed on bacteria and excrete surplus inorganic-P. , More research is needed to determine the relative contributions of the various processes above to the values close to equilibrium we report.…”

Section: Discussionmentioning

confidence: 99%

“…The soils we study go through wet–dry cycles that can release enzymes from inside the cells. Indeed, free pyrophosphatase was observed in dried soils that were rewetted in the lab. , …”

Section: Discussionmentioning

confidence: 99%

Soil Phosphate Stable Oxygen Isotopes across Rainfall and Bedrock Gradients

Angert

Weiner

Mazeh

et al. 2012

Environ. Sci. Technol.

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The stable oxygen isotope compositions of soil phosphate (δ(18)O(p)) were suggested recently to be a tracer of phosphorus cycling in soils and plants. Here we present a survey of bioavailable (resin-extractable or resin-P) inorganic phosphate δ(18)O(p) across natural and experimental rainfall gradients, and across soil formed on sedimentary and igneous bedrock. In addition, we analyzed the soil HCl-extractable inorganic δ(18)O(p), which mainly represents calcium-bound inorganic phosphate. The resin-P values were in the range 14.5-21.2‰. A similar range, 15.6-21.3‰, was found for the HCl-extractable inorganic δ(18)O(p), with the exception of samples from a soil of igneous origin that show lower values, 8.2-10.9‰, which indicate that a large fraction of the inorganic phosphate in this soil is still in the form of a primary mineral. The available-P δ(18)O(p) values are considerably higher than the values we calculated for extracellular hydrolysis of organic phosphate, based on the known fractionation from lab experiments. However, these values are close to the values expected for enzymatic-mediated phosphate equilibration with soil-water. The possible processes that can explain this observation are (1) extracellular equilibration of the inorganic phosphate in the soil; (2) fractionations in the soil are different than the ones measured at the lab; (3) effect of fractionation during uptake; and (4) a flux of intercellular-equilibrated inorganic phosphate from the soil microbiota, which is considerably larger than the flux of hydrolyzed organic-P.

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Enzyme activities in Appalachian soils: 3. Pyro‐phosphatase

Cited by 7 publications

References 20 publications

Seasonal variability of soil phosphate stable oxygen isotopes in rainfall manipulation experiments

Seasonal variability of soil phosphate stable oxygen isotopes in rainfall manipulation experiments

Response of mycorrhizal western red cedar to organic phosphorus sources and benomyl

Soil Phosphate Stable Oxygen Isotopes across Rainfall and Bedrock Gradients

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