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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

Total emergence and maximum height of Koeleria macrantha seedlings grown in soils collected from five sites in Montana and four sites in Romania, and in treatments with and without (±)-catechin.(±)-Catechin had been added to the soil 12 days prior to sowing seeds, and the numbers below the bars show the concentration in the soil two days before adding seeds. Error bars show 1 SE and asterisks denote significant differences between treatments at a particular site as determined by separate t-tests. The analysis from the complete ANOVA model is presented in the results.
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pone-0002536-g006: Total emergence and maximum height of Koeleria macrantha seedlings grown in soils collected from five sites in Montana and four sites in Romania, and in treatments with and without (±)-catechin.(±)-Catechin had been added to the soil 12 days prior to sowing seeds, and the numbers below the bars show the concentration in the soil two days before adding seeds. Error bars show 1 SE and asterisks denote significant differences between treatments at a particular site as determined by separate t-tests. The analysis from the complete ANOVA model is presented in the results.

Mentions: In the fourth experiment with soils from Montana and Romania, when seeds were planted after (±)-catechin concentrations had been allowed to decline for 12 days (see Fig. 3), treatment of the soils with (±)-catechin corresponded with significantly lower seedling emergence, height, and survival (Figs. 6, 7). Planted 12 days after (±)-catechin application, and after soil concentrations had decreased to low or undetectable levels, seedling emergence of Koeleria was inhibited significantly in 5 of the 9 soils and seedling height was reduced in 3 of the 9 soils. Using an ANOVA model with untransformed data (the means for each pot), with continent and treatment as fixed variables and site as a random variable, only the effect of (±)-catechin treatment was significant for emergence (F = 64.12; df = 1,54; P = 0.004) and for height (F = 32.55; df = 1,40; P = 0.0011). Furthermore, the survival of Koeleria seedlings in the (±)-catechin treatment decreased much faster after being exposed to drought than seedlings in control soils (Fig. 7). Kaplan-Meier Survival Analysis demonstrated significantly lower survival among Koeleria seedlings exposed to drought in the (±)-catechin treatment than in the control (Log-rank Chi-square = 7.224; df = 1; P = 0.007; Breslow Chi-square = 3.297; df = 1; P = 0.069; Tarone-Ware Chi-square = 4.703; df = 1; P = 0.030).


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

- PLoS ONE (2008)

Total emergence and maximum height of Koeleria macrantha seedlings grown in soils collected from five sites in Montana and four sites in Romania, and in treatments with and without (±)-catechin.(±)-Catechin had been added to the soil 12 days prior to sowing seeds, and the numbers below the bars show the concentration in the soil two days before adding seeds. Error bars show 1 SE and asterisks denote significant differences between treatments at a particular site as determined by separate t-tests. The analysis from the complete ANOVA model is presented in the results.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0002536-g006: Total emergence and maximum height of Koeleria macrantha seedlings grown in soils collected from five sites in Montana and four sites in Romania, and in treatments with and without (±)-catechin.(±)-Catechin had been added to the soil 12 days prior to sowing seeds, and the numbers below the bars show the concentration in the soil two days before adding seeds. Error bars show 1 SE and asterisks denote significant differences between treatments at a particular site as determined by separate t-tests. The analysis from the complete ANOVA model is presented in the results.
Mentions: In the fourth experiment with soils from Montana and Romania, when seeds were planted after (±)-catechin concentrations had been allowed to decline for 12 days (see Fig. 3), treatment of the soils with (±)-catechin corresponded with significantly lower seedling emergence, height, and survival (Figs. 6, 7). Planted 12 days after (±)-catechin application, and after soil concentrations had decreased to low or undetectable levels, seedling emergence of Koeleria was inhibited significantly in 5 of the 9 soils and seedling height was reduced in 3 of the 9 soils. Using an ANOVA model with untransformed data (the means for each pot), with continent and treatment as fixed variables and site as a random variable, only the effect of (±)-catechin treatment was significant for emergence (F = 64.12; df = 1,54; P = 0.004) and for height (F = 32.55; df = 1,40; P = 0.0011). Furthermore, the survival of Koeleria seedlings in the (±)-catechin treatment decreased much faster after being exposed to drought than seedlings in control soils (Fig. 7). Kaplan-Meier Survival Analysis demonstrated significantly lower survival among Koeleria seedlings exposed to drought in the (±)-catechin treatment than in the control (Log-rank Chi-square = 7.224; df = 1; P = 0.007; Breslow Chi-square = 3.297; df = 1; P = 0.069; Tarone-Ware Chi-square = 4.703; df = 1; P = 0.030).

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