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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

Shoot mass of Bambusa arundinacea seedlings exposed to different soil concentrations of (±)-catechin applied in multiple pulses.The x axis shows total measured concentrations of (±)-catechin below the bars and the applied concentrations in parentheses. Bars show 1 SE and shared letters indicate no significant difference among means as determined by ANOVA with treatment and pot as fixed variables and post-ANOVA Tukey tests; P<0.05.
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pone-0002536-g004: Shoot mass of Bambusa arundinacea seedlings exposed to different soil concentrations of (±)-catechin applied in multiple pulses.The x axis shows total measured concentrations of (±)-catechin below the bars and the applied concentrations in parentheses. Bars show 1 SE and shared letters indicate no significant difference among means as determined by ANOVA with treatment and pot as fixed variables and post-ANOVA Tukey tests; P<0.05.

Mentions: In the second experiment, designed to test the effect of pulsing larger quantities of (±)-catechin into the soil, applications of total amounts of 0 (control), 340, 680 and 1020 µg g−1 of (±)-catechin achieved mean measured concentrations over the course of the experiment of 1.4±1.4 (1SE), 14.5±5.8, and 36.1±10.2 µg g−1, respectively, in soils (Fig. 3). However, even at these very low soil concentrations, significant phytotoxicity was observed for shoot mass of Bambusa at 1.4±1.4, 14.5±5.8, and 36.1±10.2 µg g−1 µg g−1 (Fig. 4). It is important to note; however, that seeds and seedlings were briefly exposed to higher concentrations of (±)-catechin each time a pulse was added.


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

- PLoS ONE (2008)

Shoot mass of Bambusa arundinacea seedlings exposed to different soil concentrations of (±)-catechin applied in multiple pulses.The x axis shows total measured concentrations of (±)-catechin below the bars and the applied concentrations in parentheses. Bars show 1 SE and shared letters indicate no significant difference among means as determined by ANOVA with treatment and pot as fixed variables and post-ANOVA Tukey tests; P<0.05.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0002536-g004: Shoot mass of Bambusa arundinacea seedlings exposed to different soil concentrations of (±)-catechin applied in multiple pulses.The x axis shows total measured concentrations of (±)-catechin below the bars and the applied concentrations in parentheses. Bars show 1 SE and shared letters indicate no significant difference among means as determined by ANOVA with treatment and pot as fixed variables and post-ANOVA Tukey tests; P<0.05.
Mentions: In the second experiment, designed to test the effect of pulsing larger quantities of (±)-catechin into the soil, applications of total amounts of 0 (control), 340, 680 and 1020 µg g−1 of (±)-catechin achieved mean measured concentrations over the course of the experiment of 1.4±1.4 (1SE), 14.5±5.8, and 36.1±10.2 µg g−1, respectively, in soils (Fig. 3). However, even at these very low soil concentrations, significant phytotoxicity was observed for shoot mass of Bambusa at 1.4±1.4, 14.5±5.8, and 36.1±10.2 µg g−1 µg g−1 (Fig. 4). It is important to note; however, that seeds and seedlings were briefly exposed to higher concentrations of (±)-catechin each time a pulse was added.

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