Bidens pilosa L. Exhibits High Sensitivity to Coumarin in Comparison with Three Other Weed Species

Abstract

Nine natural plant compounds were screened for phytotoxicity to Bidens pilosa L. a troublesome weed in field and plantation crops. The sensitivity of three other weed species to coumarin, the most active identified compound, was also evaluated. Coumarin, at a concentration of 500 microM, had little effect on germination and growth of Senna obtusifolia L., Euphorbia heterophylla L., and Ipomoea grandifolia L. when compared with its effects on B. pilosa L. In a concentration range of 10-100 microM, coumarin caused a dose-dependent inhibition of germination and growth of B. pilosa L. The measurements of some parameters of energy metabolism revealed that coumarin-treated root tissues exhibited characteristics of seedlings in an earlier stage of growth, including higher respiratory activity and higher activities of alcohol dehydrogenase and lipoxygenase. These results suggest that coumarin inhibition of germination and growth of B. pilosa L. was not a consequence of an impairment of energy metabolism. Rather, it seems to act as a cytostatic agent, retarding germination. At concentrations above 50 microM, coumarin increased lipoxygenase activity and the level of conjugated dienes of root extracts, suggesting that it may induce oxidative stress in seedling roots.

Discovery and Weed Inhibition Effects of Coumarin as the Predominant Allelochemical of Yellow Sweetclover (Melilotus officinalis)

“…5). In addition, different plants showed different degrees of sensitivity to the phytotoxic activity of coumarin, which was consistent with the reports of Pergo et al (2008).…”

“…Xanthyletin, a pyranocoumarin, shows very high phytotoxic activity on the seed germination of Amaranthus hypochondriacus with IC50 values of 59.9 and 69.5 μg mL -1 (Anya et al, 2005). At 10 μM to 100 μM, coumarin inhibits the seed germination of Bidens (Bidens pilosa L.) to different levels; at lower concentrations, coumarin as a cytostatic delays the seed germination of Bidens (Pergo et al, 2008). In the present study, we found that coumarin apparently delayed the seed germination of all tested plants (Fig.…”

“…These properties decrease a chemical's environmental half-life, thus preventing the accumulation of the compound in soil and eventually inhibiting effects on non-target organisms (Razavi et al, 2010c). Based on these characteristics, coumarin could be used as a natural herbicide in various ways (Pergo et al, 2008). For example, using plants with high coumarin content for intercropping or crop-rotation systems to reduce weeds, which are already in practice in yellow sweetclover.…”

Influence of different cover crops on the emergence and development of Digitaria horizontalis

“…In this context, management alternatives as cultural methods, with biomass presence on soil surface has potential to assist the integrated management of weeds (Moraes et al, 2011), via physical, chemical-allelopathy and microbiological processes (Pacheco et al, 2009;Pergo et al, 2008).…”

Croton argenteus preparation inhibits initial growth, mitochondrial respiration and increase the oxidative stress from Senna occidentalis seedlings

“…Mitochondrial metabolism is essential for energy production and precursors for the biosynthesis of new cellular structures. An effect on respiratory metabolism may be used as a mechanism of action of natural substances to suppress weed germination and growth (Pergo et al 2008). Based in these aspects, the aim of this work was to identify if the crude ethanolic extract and fractions of C. argenteus present high and selective phytotoxicity in S. occidentalis, by interfering in germination, growth, oxidative stress, mitochondrial ATP synthesis, L-malate and succinate alterations.…”