The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Anne Atlan - One of the best experts on this subject based on the ideXlab platform.
-
the invasive niche a multidisciplinary concept illustrated by gorse Ulex Europaeus
2019Co-Authors: Anne Atlan, Nathalie UdoAbstract:This study analyzes the natural and social factors influencing the emergence and publicization of the invasive status of a fast-growing bush, gorse (Ulex Europaeus), by comparison between countries on a global scale. We used documents collected on the web in a standardized way. The results show that in all the countries studied, there are several public statuses attributed to gorse. The invasive status is the one that is most shared. The other most frequently encountered status are those of noxious weed, and those of which are economically useful. The invasive status is publicized in nearly all countries, including those where gorse is almost absent. We quantified the publicization of the invasive gorse status of gorse by an indicator with 5 levels, and then performed a multivariate analysis that combines natural and social explanatory variables. The results lead us to propose the concept of invasive niche, which is the set of natural and social parameters that allow a species to be considered invasive in a given socio-ecosystem
-
Evolution of germination strategy in the invasive species Ulex Europaeus
Journal of Plant Ecology, 2017Co-Authors: Nathalie Udo, Michele Tarayre, Anne AtlanAbstract:Aims The study of the adaptive potential of the germination patterns of invading species enables us to identify some traits linked with their capacity to colonize new sites, and to gain a better understanding of their area of distribution. The aim of this study is to determine the germination pattern of Ulex Europaeus, a cosmopolitan invasive species, in relation to temperature and to explore its potential evolution and invasiveness in a tropical region, following its introduction from Europe. Methods: We studied the germination pattern of U. Europaeus (the common gorse) to test both physical dormancy and germination capacity within the range of temperatures found in the native and invasive regions. To understand its germination pattern and its evolution, the rate and the speed of germination, as well as the percentage of seeds that became mouldy during the experiment, have been compared between a native habitat, France and a habitat into which it has been introduced, the tropical island of La Reunion. Important Findings The results show that gorse seeds germinate in large quantities, possess the ability to germinate under a wide range of temperatures and they confirm the physical dormancy of the seeds (caused by seed coat impermeability). The decrease in germination from 25 degrees C upwards, coupled with an increase in the rate of moulding help to explain its restricted distribution at altitude in tropical environments. For scarified seeds, we have not detected any difference between the two regions, neither in the percentage of germinated seeds, nor in the percentage of mouldy seeds. However, seeds from Reunion germinate faster at 20 degrees C than seeds from France and a greater number of seeds from Reunion are able to germinate without scarification (10-60% for Reunion versus 0-10% for France). These results suggest that while preserving the advantages of the native habitat, in Reunion gorse develops a strategy which favours the rapid occupation of new sites.
-
self incompatibility in Ulex Europaeus variations in native and invaded regions
International Journal of Plant Sciences, 2015Co-Authors: Anne Atlan, Agnes Schermannlegionnet, Nathalie Udo, Michele TarayreAbstract:Premise of research. The mating systems of introduced plant species are important components of their invasive success because they can favor reproductive assurance during the colonization process. The hypothesis known as Baker’s rule implies that colonizing species should evolve toward a lower dependence on pollinators, a higher self-fertility, and a lower inbreeding depression. Here, we test these predictions by comparing the mating system of the perennial shrub Ulex Europaeus (Fabaceae) in regions from its native and invaded ranges.Methodology. We performed controlled pollinations on plants from two regions of origin (Brittany and Scotland) and two invaded regions (New Zealand and Reunion) grown in a common garden. We tested the possibility of autonomous pollination; estimated the relative seed set of selfing versus outcrossing; and recorded the viability, mass, and germination capacity of the seeds produced.Pivotal results. Ulex Europaeus cannot set seeds in the absence of active pollination. Seed set...
-
temporal fluctuations in the environment and intra specific polymorphism a model simulating the flowering phenology of gorse Ulex Europaeus
Ecological Modelling, 2015Co-Authors: Jeremy Rio, Jeansebastien Pierre, Pascaline Le Gouar, Anne AtlanAbstract:The onset and conservation of genetic polymorphism is a major question in evolutionary ecology. The influence of temporal fluctuations in the environment was invoked by early theorists such as J.B.S. Haldane and S. Jayakar in a controversial article published in, 1963, but their frequently cited model has almost never been used with empirical evidence. In this paper, we present a simulation model inspired by the biology of common gorse (Ulex Europaeus), a species which shows polymorphism of flowering phenology: long flowering plants produce flowers from winter to spring and short flowering plants only flower in the spring. The early fruits of the former run the risk of frost, but largely escape seed predation, while those of the latter escape the risk of frost but are subject to a strong risk of seed predation. These two selection pressures vary unpredictably from year to year, making this flowering phenotype a good candidate to test Haldane and Jayakar’s model. Assuming that both flowering types are determined by a single major locus, we devise a simulation model firstly in a diploid form, and secondly by taking into account the hexaploid characteristic of gorse. Our results show that the combination of the two selective pressures acting on gorse flowering phenology can lead to fitness values meeting the Haldane and Jayakar’s conditions on geometric and arithmetic means, and to long term maintenance of polymorphism. In addition, the values of the parameters allowing polymorphism persistence and the relative proportions obtained are in agreement with values observed in natural populations. We also show that hexaploidy strongly increases the range of parameters in which polymorphism is self sustaining. These results are discussed in the context of climatic change, where increases of both mean temperature and its variance are predicted.
-
Pre-dispersal seed predation of gorse (Ulex Europaeus) along gradients of light and plant density
New Zealand Journal of Ecology, 2014Co-Authors: Florian Delerue, Anne Atlan, Maya Gonzalez, Sylvain Pellerin, Laurent AugustoAbstract:Common gorse (Ulex Europaeus) is one of the most invasive species worldwide. Biological control of gorse by two pre-dispersal seed predators (the weevil Exapion ulicis and the moth Cydia succedana) is used in New Zealand. Gorse shrubs are distributed along wide natural gradients, and this could influence seed predation. The aim of this study was to identify factors that influence seed predation along two natural gradients, of light availability and gorse density. Seed predation was studied in the native range of the species, in south-west France. A total of 140 shrubs in stands with different irradiance and population densities were monitored. The number of seeds damaged was determined at different scales: the pod, the shrub and the gorse stand. The multi-scale analysis revealed that weevil activity increased with the quantity of gorse seeds produced, mainly at the pod and plot scales. The moth appeared satiated by abundant seed production at the bush and plot scales. In addition,moth activity was maintained in shady plots where weevil activity decreased. On the whole predation intensity was high and varied little along the density gradient (about 60–80% of seeds destroyed). Conversely, predation intensity decreased significantly with shade (from about 80% in full-light plots to 25% of seeds destroyed in the shadiest plots). These results could help predict the impact of pre-dispersal seed predation on the dynamics of gorse populations along environmental gradients. The activity of the moth appeared to be complementary to that of the weevil because it was maintained where the weevil was rare (i.e. in shady environments). Thus, the joint presence of the two predators may be helpful in the context of biological control of gorse.
Nuria Pedrol - One of the best experts on this subject based on the ideXlab platform.
-
Water-soluble phenolic acids and flavonoids involved in the bioherbicidal potential of Ulex Europaeus and Cytisus scoparius
South African Journal of Botany, 2020Co-Authors: María Pardo-muras, Carolina G. Puig, X. Carlos Souto, Nuria PedrolAbstract:Abstract The use of allelopathic foliage incorporated into the soil as a bioherbicidal amendment is a promising weed management strategy which allows combining a cocktail of allelochemicals at low effective individual concentrations. In previous studies, the herbicidal potential of Ulex Europaeus and Cytisus scoparius has been argued to be mediated by volatile organic compounds (VOCs). The present work undertakes for the first time the potential involvement of phenolic acids and flavonoids in the herbicidal bioactivity of both shrub species. Such compounds are those most likely to be released to soil water when the allelopathic foliage is incorporated into the soil. By dose-response in vitro bioassays of aqueous extracts, the flowering foliage of both shrub species was shown to release water-soluble compounds capable of inhibiting the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Far from expected, such phytotoxicity was enhanced when the aqueous extracts were applied to fresh soil. Via HPLC-DAD, 11 and 17 phenolic compounds were identified from U. Europaeus and C. scoparius aqueous extracts, respectively, some of them cited for the first time in both species. The phenolic acids trans-cinnamic, p-coumaric, and ferulic, when were separately assayed in vitro at 1 mM, resulted phytotoxic to one or other target weed and physiological processes. However, except for the caffeic acid and vanillin, the phenolic acids lost effectiveness when applied at lower concentrations (0.1 or 0.01 mM). Otherwise, it was noteworthy that the flavonoids luteolin, ellagic acid, kaempferol, and naringenin were only phytotoxic when applied at low concentrations (≤0.1 mM). The proven herbicidal efficiency of the shrub foliage was argued to derive from the phytotoxicity of the water-soluble compounds assayed, and maybe from the combined or synergistic action with the VOCs emitted from the fresh plant material.
-
cytisus scoparius and Ulex Europaeus produce volatile organic compounds with powerful synergistic herbicidal effects
Molecules, 2019Co-Authors: Maria Pardomuras, Carolina G. Puig, Nuria PedrolAbstract:New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex Europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth.
-
on the bioherbicide potential of Ulex Europaeus and cytisus scoparius profiles of volatile organic compounds and their phytotoxic effects
PLOS ONE, 2018Co-Authors: Maria Pardomuras, Carolina G. Puig, Antonio Lopeznogueira, Carlos Cavaleiro, Nuria PedrolAbstract:The phytotoxic potential of the legume shrubs Ulex Europaeus L. (gorse) and Cytisus scoparius (L.) Link. (Scotch broom) is studied in this work for the first time. On the basis of their richness in active principles, the previous evidence of biological activity, and the abundance of biomass in their native range and invaded areas, a question arose: can U. Europaeus and C. scoparius be considered as potential sources of natural herbicides for sustainable agriculture? By means of volatile bioassays, the flowering fresh plant material of both shrub species was shown to produce and emit volatile organic compounds (VOCs) able to inhibit the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Novel complete VOCs profiles from the volatile extracts of the shrub species were obtained by GC and GC/MS. A total of 20 compounds were identified from U. Europaeus flowering biomass, theaspirane and eugenol, among others, being described in gorse for the first instance. The chemical profile of C. scoparius yielded 28 compounds and was rich in oxygenated monoterpenes such as terpinen-4-ol, verbenol, α-terpineol, and verbenone, which were also identified in this species for the first time. Using dose-response bioassays with pure compounds, these VOCs were argued to be involved in the phytotoxicity observed for the plant materials, even at very low concentrations. The phytotoxic effects were predominantly irreversible, particularly for D. sanguinalis, since the seeds exposed to the VOCs produced damaged seedlings, were unable to recover germination capacity after removing the phytotoxin or, when recovered, produced unviable seedlings. Our results extend the interest of the abundant U. Europaeus and C. scoparius for the obtention of natural products with bioherbicide potential, or to be used as allelopathic biomass in the development of new sustainable agricultural practices.
Maria Pardomuras - One of the best experts on this subject based on the ideXlab platform.
-
cytisus scoparius and Ulex Europaeus produce volatile organic compounds with powerful synergistic herbicidal effects
Molecules, 2019Co-Authors: Maria Pardomuras, Carolina G. Puig, Nuria PedrolAbstract:New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex Europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth.
-
on the bioherbicide potential of Ulex Europaeus and cytisus scoparius profiles of volatile organic compounds and their phytotoxic effects
PLOS ONE, 2018Co-Authors: Maria Pardomuras, Carolina G. Puig, Antonio Lopeznogueira, Carlos Cavaleiro, Nuria PedrolAbstract:The phytotoxic potential of the legume shrubs Ulex Europaeus L. (gorse) and Cytisus scoparius (L.) Link. (Scotch broom) is studied in this work for the first time. On the basis of their richness in active principles, the previous evidence of biological activity, and the abundance of biomass in their native range and invaded areas, a question arose: can U. Europaeus and C. scoparius be considered as potential sources of natural herbicides for sustainable agriculture? By means of volatile bioassays, the flowering fresh plant material of both shrub species was shown to produce and emit volatile organic compounds (VOCs) able to inhibit the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Novel complete VOCs profiles from the volatile extracts of the shrub species were obtained by GC and GC/MS. A total of 20 compounds were identified from U. Europaeus flowering biomass, theaspirane and eugenol, among others, being described in gorse for the first instance. The chemical profile of C. scoparius yielded 28 compounds and was rich in oxygenated monoterpenes such as terpinen-4-ol, verbenol, α-terpineol, and verbenone, which were also identified in this species for the first time. Using dose-response bioassays with pure compounds, these VOCs were argued to be involved in the phytotoxicity observed for the plant materials, even at very low concentrations. The phytotoxic effects were predominantly irreversible, particularly for D. sanguinalis, since the seeds exposed to the VOCs produced damaged seedlings, were unable to recover germination capacity after removing the phytotoxin or, when recovered, produced unviable seedlings. Our results extend the interest of the abundant U. Europaeus and C. scoparius for the obtention of natural products with bioherbicide potential, or to be used as allelopathic biomass in the development of new sustainable agricultural practices.
Barry H. Hirst - One of the best experts on this subject based on the ideXlab platform.
-
Ulex Europaeus 1 lectin targets microspheres to mouse Peyer's patch M-cells in vivo
Vaccine, 1998Co-Authors: Neil Foster, Mark A. Jepson, Ma Clark, Barry H. HirstAbstract:The interaction of latex microspheres with mouse Peyer's patch membranous M-cells was studied in a mouse gut loop model after the microspheres were coated with a variety of agents. Carboxylated microspheres (diameter 0.5 μm) were covalently coated with lectins Ulex Europaeus 1, Concanavalin A, Euonymus Europaeus and Bandeiraea simplicifolia 1 isolectin-B4, human immunoglobulin A or bovine serum albumin. Of the treatments examined, only Ulex Europaeus (UEA1) resulted in significant selective binding of microspheres to M-cells. UEA1-coated microspheres bound to M-cells at a level 100-fold greater than BSA-coated microspheres, but binding to enterocytes was unaffected. Incubation of UEA1-coated microspheres with α-L-fucose reduced M-cell binding to a level comparable with BSA-coated microspheres. This indicated that targeting by UEA1 was via a carbohydrate receptor on the M-cell surface. Adherence of UEA1-coated microspheres to M-cells occurred within 10 min of inoculation into mouse gut loops and UEA1-coated microspheres were transported to 10 μm below the apical surface of M-cells within 60 min of inoculation. UEA1-coated microspheres also targeted mouse Peyer's patch M-cells after intragastric administration. These results demonstrated that altering the surface chemistry of carboxylated polystyrene microspheres increased M-cell targetting, suggesting a strategy to enhance delivery of vaccine antigens to the mucosal immune system.
-
selective binding and transcytosis of Ulex Europaeus 1 lectin by mouse peyer s patch m cells in vivo
Cell and Tissue Research, 1995Co-Authors: Ann M Clark, Mark A. Jepson, N L Simmons, Barry H. HirstAbstract:The in vivo interaction of the lectin Ulex Europaeus agglutinin 1 with mouse Peyer's patch follicle-associated epithelial cells was studied in the mouse Peyer's patch gut loop model by immunofluorescence and electron microscopy. The lectin targets to mouse Peyer's patch M-cells and is rapidly endocytosed and transcytosed. These processes are accompanied by morphological changes in the M-cell microvilli and by redistribution of polymerised actin. The demonstration of selective binding and uptake of a lectin by intestinal M-cells in vivo suggests that M-cell-specific surface glycoconjugates might act as receptors for the selective adhesion/uptake of microorganisms.
Carolina G. Puig - One of the best experts on this subject based on the ideXlab platform.
-
Water-soluble phenolic acids and flavonoids involved in the bioherbicidal potential of Ulex Europaeus and Cytisus scoparius
South African Journal of Botany, 2020Co-Authors: María Pardo-muras, Carolina G. Puig, X. Carlos Souto, Nuria PedrolAbstract:Abstract The use of allelopathic foliage incorporated into the soil as a bioherbicidal amendment is a promising weed management strategy which allows combining a cocktail of allelochemicals at low effective individual concentrations. In previous studies, the herbicidal potential of Ulex Europaeus and Cytisus scoparius has been argued to be mediated by volatile organic compounds (VOCs). The present work undertakes for the first time the potential involvement of phenolic acids and flavonoids in the herbicidal bioactivity of both shrub species. Such compounds are those most likely to be released to soil water when the allelopathic foliage is incorporated into the soil. By dose-response in vitro bioassays of aqueous extracts, the flowering foliage of both shrub species was shown to release water-soluble compounds capable of inhibiting the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Far from expected, such phytotoxicity was enhanced when the aqueous extracts were applied to fresh soil. Via HPLC-DAD, 11 and 17 phenolic compounds were identified from U. Europaeus and C. scoparius aqueous extracts, respectively, some of them cited for the first time in both species. The phenolic acids trans-cinnamic, p-coumaric, and ferulic, when were separately assayed in vitro at 1 mM, resulted phytotoxic to one or other target weed and physiological processes. However, except for the caffeic acid and vanillin, the phenolic acids lost effectiveness when applied at lower concentrations (0.1 or 0.01 mM). Otherwise, it was noteworthy that the flavonoids luteolin, ellagic acid, kaempferol, and naringenin were only phytotoxic when applied at low concentrations (≤0.1 mM). The proven herbicidal efficiency of the shrub foliage was argued to derive from the phytotoxicity of the water-soluble compounds assayed, and maybe from the combined or synergistic action with the VOCs emitted from the fresh plant material.
-
cytisus scoparius and Ulex Europaeus produce volatile organic compounds with powerful synergistic herbicidal effects
Molecules, 2019Co-Authors: Maria Pardomuras, Carolina G. Puig, Nuria PedrolAbstract:New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex Europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth.
-
on the bioherbicide potential of Ulex Europaeus and cytisus scoparius profiles of volatile organic compounds and their phytotoxic effects
PLOS ONE, 2018Co-Authors: Maria Pardomuras, Carolina G. Puig, Antonio Lopeznogueira, Carlos Cavaleiro, Nuria PedrolAbstract:The phytotoxic potential of the legume shrubs Ulex Europaeus L. (gorse) and Cytisus scoparius (L.) Link. (Scotch broom) is studied in this work for the first time. On the basis of their richness in active principles, the previous evidence of biological activity, and the abundance of biomass in their native range and invaded areas, a question arose: can U. Europaeus and C. scoparius be considered as potential sources of natural herbicides for sustainable agriculture? By means of volatile bioassays, the flowering fresh plant material of both shrub species was shown to produce and emit volatile organic compounds (VOCs) able to inhibit the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Novel complete VOCs profiles from the volatile extracts of the shrub species were obtained by GC and GC/MS. A total of 20 compounds were identified from U. Europaeus flowering biomass, theaspirane and eugenol, among others, being described in gorse for the first instance. The chemical profile of C. scoparius yielded 28 compounds and was rich in oxygenated monoterpenes such as terpinen-4-ol, verbenol, α-terpineol, and verbenone, which were also identified in this species for the first time. Using dose-response bioassays with pure compounds, these VOCs were argued to be involved in the phytotoxicity observed for the plant materials, even at very low concentrations. The phytotoxic effects were predominantly irreversible, particularly for D. sanguinalis, since the seeds exposed to the VOCs produced damaged seedlings, were unable to recover germination capacity after removing the phytotoxin or, when recovered, produced unviable seedlings. Our results extend the interest of the abundant U. Europaeus and C. scoparius for the obtention of natural products with bioherbicide potential, or to be used as allelopathic biomass in the development of new sustainable agricultural practices.
