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Phytotoxic effects of (+/-)-catechin in vitro, in soil, and in the field.

- PLoS ONE (2008)

Bottom Line: Experimental application of (+/-)-catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations.Our results demonstrate that (+/-)-catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied at low concentrations in the field.However, there is substantial conditionality in the effects of the allelochemical.

View Article: PubMed Central - PubMed

Affiliation: Centre for Environmental Management of Degraded Ecosystems, University of Delhi, Delhi, India. inderjit@cemde.du.ac.in

ABSTRACT

Background: Exploring the residence time of allelochemicals released by plants into different soils, episodic exposure of plants to allelochemicals, and the effects of allelochemicals in the field has the potential to improve our understanding of interactions among plants.

Methodology/principal findings: We conducted experiments in India and the USA to understand the dynamics of soil concentrations and phytotoxicity of (+/-)-catechin, an allelopathic compound exuded from the roots of Centaurea maculosa, to other plants in vitro and in soil. Experiments with single and pulsed applications into soil were conducted in the field. Experimental application of (+/-)-catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations. Pulses replenished (+/-)-catechin levels in soils, but consistently at concentrations much lower than were applied, and even pulsed concentrations declined rapidly. Different natural soils varied substantially in the retention of (+/-)-catechin after application but consistent rapid decreases in concentrations over time suggested that applied experimental concentrations may overestimate concentrations necessary for phytotoxicity by over an order of magnitude. (+/-)-Catechin was not phytotoxic to Bambusa arundinacea in natural Indian soil in a single pulse, but soil concentrations at the time of planting seeds were either undetectable or very low. However, a single dose of (+/-)-catechin suppressed the growth of bamboo in sand, in soil mixed with organic matter, and Koeleria macrantha in soils from Montana and Romania, and in field applications at 40 microg l(-1). Multiple pulses of (+/-)-catechin were inhibitory at very low concentrations in Indian soil.

Conclusions/significance: Our results demonstrate that (+/-)-catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied at low concentrations in the field. However, there is substantial conditionality in the effects of the allelochemical.

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Related in: MedlinePlus

Change in leaf number for Koeleria macrantha in the field with and without (±)-catechin injected into rhizosphere soils.Error bars show 1 SE. We tested the effects of (±)-catechin on growth across all sites (n = 15 in each treatment at each site) with a two way ANOVA, with (±)-catechin as a fixed factor and site as a random factor (SPSS 15.0, SPSS, Chicago). ANOVA, Ftreatment = 8.86; df = 1,196; P = 0.025, Fsite = 3.09; df = 6,196; P = 0.098).
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pone-0002536-g008: Change in leaf number for Koeleria macrantha in the field with and without (±)-catechin injected into rhizosphere soils.Error bars show 1 SE. We tested the effects of (±)-catechin on growth across all sites (n = 15 in each treatment at each site) with a two way ANOVA, with (±)-catechin as a fixed factor and site as a random factor (SPSS 15.0, SPSS, Chicago). ANOVA, Ftreatment = 8.86; df = 1,196; P = 0.025, Fsite = 3.09; df = 6,196; P = 0.098).

Mentions: The mean leaf growth of the control plants in the field experiment was 2.90±0.16 (1 SE) leaves per plant versus 2.45±0.15 for the plants treated with (±)-catechin (Figure 8). A subsample of soils collected immediately after application demonstrated no detectable (±)-catechin. Based on separate t-tests, there was no significant effect of (±)-catechin addition at any single site, but the overall treatment effect was significant (ANOVA, Ftreatment = 8.86; df = 1,196; P = 0.025, Fsite = 3.09; df = 6,196; P = 0.098).


Phytotoxic effects of (+/-)-catechin in vitro, in soil, and in the field.

- PLoS ONE (2008)

Change in leaf number for Koeleria macrantha in the field with and without (±)-catechin injected into rhizosphere soils.Error bars show 1 SE. We tested the effects of (±)-catechin on growth across all sites (n = 15 in each treatment at each site) with a two way ANOVA, with (±)-catechin as a fixed factor and site as a random factor (SPSS 15.0, SPSS, Chicago). ANOVA, Ftreatment = 8.86; df = 1,196; P = 0.025, Fsite = 3.09; df = 6,196; P = 0.098).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2481294&req=5

pone-0002536-g008: Change in leaf number for Koeleria macrantha in the field with and without (±)-catechin injected into rhizosphere soils.Error bars show 1 SE. We tested the effects of (±)-catechin on growth across all sites (n = 15 in each treatment at each site) with a two way ANOVA, with (±)-catechin as a fixed factor and site as a random factor (SPSS 15.0, SPSS, Chicago). ANOVA, Ftreatment = 8.86; df = 1,196; P = 0.025, Fsite = 3.09; df = 6,196; P = 0.098).
Mentions: The mean leaf growth of the control plants in the field experiment was 2.90±0.16 (1 SE) leaves per plant versus 2.45±0.15 for the plants treated with (±)-catechin (Figure 8). A subsample of soils collected immediately after application demonstrated no detectable (±)-catechin. Based on separate t-tests, there was no significant effect of (±)-catechin addition at any single site, but the overall treatment effect was significant (ANOVA, Ftreatment = 8.86; df = 1,196; P = 0.025, Fsite = 3.09; df = 6,196; P = 0.098).

Bottom Line: Experimental application of (+/-)-catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations.Our results demonstrate that (+/-)-catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied at low concentrations in the field.However, there is substantial conditionality in the effects of the allelochemical.

View Article: PubMed Central - PubMed

Affiliation: Centre for Environmental Management of Degraded Ecosystems, University of Delhi, Delhi, India. inderjit@cemde.du.ac.in

ABSTRACT

Background: Exploring the residence time of allelochemicals released by plants into different soils, episodic exposure of plants to allelochemicals, and the effects of allelochemicals in the field has the potential to improve our understanding of interactions among plants.

Methodology/principal findings: We conducted experiments in India and the USA to understand the dynamics of soil concentrations and phytotoxicity of (+/-)-catechin, an allelopathic compound exuded from the roots of Centaurea maculosa, to other plants in vitro and in soil. Experiments with single and pulsed applications into soil were conducted in the field. Experimental application of (+/-)-catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations. Pulses replenished (+/-)-catechin levels in soils, but consistently at concentrations much lower than were applied, and even pulsed concentrations declined rapidly. Different natural soils varied substantially in the retention of (+/-)-catechin after application but consistent rapid decreases in concentrations over time suggested that applied experimental concentrations may overestimate concentrations necessary for phytotoxicity by over an order of magnitude. (+/-)-Catechin was not phytotoxic to Bambusa arundinacea in natural Indian soil in a single pulse, but soil concentrations at the time of planting seeds were either undetectable or very low. However, a single dose of (+/-)-catechin suppressed the growth of bamboo in sand, in soil mixed with organic matter, and Koeleria macrantha in soils from Montana and Romania, and in field applications at 40 microg l(-1). Multiple pulses of (+/-)-catechin were inhibitory at very low concentrations in Indian soil.

Conclusions/significance: Our results demonstrate that (+/-)-catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied at low concentrations in the field. However, there is substantial conditionality in the effects of the allelochemical.

Show MeSH
Related in: MedlinePlus