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Marcel Dicke - One of the best experts on this subject based on the ideXlab platform.

  • Multiple Attack to Inflorescences of an Annual Plant Does Not Interfere with the Attraction of Parasitoids and Pollinators
    Journal of Chemical Ecology, 2021
    Co-Authors: Lucille T. S. Chrétien, Marcel Dicke, Hessel Van Der Heide, Liana O. Greenberg, David Giron, Dani Lucas-barbosa
    Abstract:

    Plants in the flowering stage need to ensure reproduction by protecting themselves from attack and by preserving interactions with mutualist pollinators. When different plant mutualists are using the same type of cues, such as volatile compounds, attraction of parasitoids and pollinators may trade off. To explore this, we compared volatile emission of Brassica Nigra plants in response to single or dual attack on their inflorescences. Additionally, we recorded flower visitation by pollinators and the attraction of parasitoids in the greenhouse and/or field. Brassica Nigra were exposed in the flowering stage to one or two of the following three attackers: Brevicoryne Brassicae aphids, Pieris Brassicae caterpillars, and Xanthomonas campestris pv. raphani bacteria. We found that single attack by caterpillars, and dual attack by caterpillars plus aphids, induced the strongest changes in plant volatile emission. The caterpillars’ parasitoid C. glomerata did not exhibit preference for plants exposed to caterpillars only vs. plants exposed to caterpillars plus aphids or plus bacteria. However, the composition of the pollinator community associated with flowers of B. Nigra was affected by plant exposure to the attackers, but the total number of pollinators visiting the plants did not change upon attack. We conclude that, when B. Nigra were exposed to single or dual attack on their inflorescences, the plants maintained interactions with natural enemies of the insect attackers and with pollinators. We discuss how chemical diversity may contribute to plant resilience upon attack.

  • leaf metabolic signatures induced by real and simulated herbivory in black mustard Brassica Nigra
    Metabolomics, 2019
    Co-Authors: Stefano Papazian, Erik H. Poelman, Marcel Dicke, Tristan Girdwood, Bernard Wessels, Thomas Moritz, Benedicte R Albrectsen
    Abstract:

    The oxylipin methyl jasmonate (MeJA) is a plant hormone active in response signalling and defence against herbivores. Although MeJA is applied experimentally to mimic herbivory and induce plant defences, its downstream effects on the plant metabolome are largely uncharacterized, especially in the context of primary growth and tissue-specificity of the response. We investigated the effects of MeJA-simulated and real caterpillar herbivory on the foliar metabolome of the wild plant Brassica Nigra and monitored the herbivore-induced responses in relation to leaf ontogeny. As single or multiple herbivory treatments, MeJA- and mock-sprayed plants were consecutively exposed to caterpillars or left untreated. Gas chromatography (GC) and liquid chromatography (LC) time-of-flight mass-spectrometry (TOF-MS) were combined to analyse foliar compounds, including central primary and specialized defensive plant metabolites. Plant responses were stronger in young leaves, which simultaneously induced higher chlorophyll levels. Both MeJA and caterpillar herbivory induced similar, but not identical, accumulation of tricarboxylic acids (TCAs), glucosinolates (GSLs) and phenylpropanoids (PPs), but only caterpillar feeding led to depletion of amino acids. MeJA followed by caterpillars caused higher induction of defence compounds, including a three-fold increase in the major defence compound allyl-GSL (sinigrin). When feeding on MeJA-treated plants, caterpillars gained less weight indicative of the reduced host-plant quality and enhanced resistance. The metabolomics approach showed that plant responses induced by herbivory extend beyond the regulation of defence metabolism and are tightly modulated throughout leaf development. This leads to a new understanding of the plant metabolic potential that can be exploited for future plant protection strategies.

  • Combined biotic stresses trigger similar transcriptomic responses but contrasting resistance against a chewing herbivore in Brassica Nigra
    BMC Plant Biology, 2017
    Co-Authors: Christelle Bonnet, Steve Lassueur, Camille Ponzio, Rieta Gols, Marcel Dicke
    Abstract:

    BackgroundIn nature, plants are frequently exposed to simultaneous biotic stresses that activate distinct and often antagonistic defense signaling pathways. How plants integrate this information and whether they prioritize one stress over the other is not well understood.ResultsWe investigated the transcriptome signature of the wild annual crucifer, Brassica Nigra, in response to eggs and caterpillars of Pieris Brassicae butterflies, Brevicoryne Brassicae aphids and the bacterial phytopathogen Xanthomonas campestris pv. raphani (Xcr). Pretreatment with egg extract, aphids, or Xcr had a weak impact on the subsequent transcriptome profile of plants challenged with caterpillars, suggesting that the second stress dominates the transcriptional response. Nevertheless, P. Brassicae larval performance was strongly affected by egg extract or Xcr pretreatment and depended on the site where the initial stress was applied. Although egg extract and Xcr pretreatments inhibited insect-induced defense gene expression, suggesting salicylic acid (SA)/jasmonic acid (JA) pathway cross talk, this was not strictly correlated with larval performance.ConclusionThese results emphasize the need to better integrate plant responses at different levels of biological organization and to consider localized effects in order to predict the consequence of multiple stresses on plant resistance.

  • early herbivore alert matters plant mediated effects of egg deposition on higher trophic levels benefit plant fitness
    Ecology Letters, 2015
    Co-Authors: Nina E Fatouros, Foteini G Pashalidou, Enric Frago, Eddie Griese, Erik H. Poelman, Joop J A Van Loon, Marcel Dicke
    Abstract:

    Induction of plant defences, specifically in response to herbivore attack, can save costs that would otherwise be needed to maintain defences even in the absence of herbivores. However, plants may suffer considerable damage during the time required to mount these defences against an attacker. This could be resolved if plants could respond to early cues, such as egg deposition, that reliably indicate future herbivory. We tested this hypothesis in a field experiment and found that egg deposition by the butterfly Pieris Brassicae on black mustard (Brassica Nigra) induced a plant response that negatively affected feeding caterpillars. The effect cascaded up to the third and fourth trophic levels (larval parasitoids and hyperparasitoids) by affecting the parasitisation rate and parasitoid performance. Overall, the defences induced by egg deposition had a positive effect on plant seed production and may therefore play an important role in the evolution of plant resistance to herbivores.

Cadenas Vásquez, Walter Jesús - One of the best experts on this subject based on the ideXlab platform.

  • Evaluación de la adsorción de plomo (II) en soluciones acuosas utilizando como bioadsorbente la especie vegetal Brassica Nigra
    'Universidad Nacional de Ingenieria', 2019
    Co-Authors: Cadenas Vásquez, Walter Jesús
    Abstract:

    Currently, lead is one of the metals that has damaged different rivers of our country in recent years. Previously it is known that the family of the Brassica Nigra has obtained good results in phytoremediation of polluted soils with heavy metals, with this research we seek to take advantage of its stem and root to remove lead from aqueous solutions. First, the biomass was characterized with FTIR analysis to identify the main functional groups, the carboxyl functional group has been reported in different research works as a possible responsible for the attraction of heavy metals. In the second stage of the thesis, it was studied three operational variables, pH, particle size and biomass/solution ratio and the influence on adsorption was verified. It was worked in three levels of lead concentration, 5, 15 and 30 mg/L and it was found that the highest removal of the metal occurred at pH 5 due to the deprotonation of the carboxyl groups present in the wall cellular bioadsorbent. The results obtained in the adsorption capacities were 7,183, 20,833 and 27,042 mg/g for 5, 15 and 30 mg/L respectively. The granulometry of the biomass was between 177 and 297 microns with a biomass/solution ratio of 0.6 g/L, this values allowed succesful results to remove lead (II) from aqueous solutions. The solid - liquid system reaches the equilibrium after 600 minutes. To know the behavior of the kinetics of the process, two kinetic models were used, describing better the non-linear model pseudo second order results; the correlation factor (R2) were 0.9998 and 0.9997 for 5 and 30 mg/L respectively. The equilibrium in the liquid was described by Langmuir Isotherm. For this study the lead concentration range were between 5 to 100 mg/L, and the maximum capacity was 53,476 mg/g. On the other hand, the equilibrium in the solid was described by the desorption of lead (II) and the best eluent capable of releasing the lead from the cell wall of the bioadsorbent was HNO3 (0.1 N). Finally, the results from this research confirm that the bioadsorbent made from the Brassica Nigra is a good alternative to treat polluted water with lead.TesisActualmente, el plomo es uno de los metales que ha generado más daños en diversas regiones en los diferentes ríos de nuestro país en los últimos años. Anteriormente se conoce que la familia de la especie Brassica Nigra ha obtenido buenos resultados en la fitorremediación de suelos contaminados con metales pesados; con este trabajo de investigación se busca aprovechar su tallo y raíz para remover el plomo de soluciones acuosas. Primero se hicieron análisis para caracterizar a la biomasa como el análisis de FT-IR para identificar los principales grupos funcionales, encontrándose al grupo funcional carboxilo que ha sido reportado en diferentes trabajos de investigación como posible responsable de la atracción del metal pesado contaminante. En la segunda etapa del trabajo se hizo el estudio de tres variables operacionales, pH, tamaño de partícula y relación biomasa/solución y verificar su influencia en la adsorción. Se trabajó en tres niveles de concentración de plomo (II), 5, 15 y 30 mg/L y se encontró que la máxima remoción del metal ocurrió a un pH final igual a 5 debido a la desprotonación de los grupos carboxilo presente en la pared celular de la biomasa. Los resultados obtenidos en las capacidades de adsorción fueron 7.183, 20.833 y 27.042 mg/g para 5, 15 y 30 mg/L respectivamente. La granulometría de la biomasa estuvo en el rango de los 177 y 297 micrones con una relación de biomasa/solución de 0.6 g/L, que permitieron resultados satisfactorios en la remoción del plomo (II). El tiempo para que el sistema sólido – líquido alcance el equilibrio fue de 600 minutos, y para conocer el comportamiento de la cinética del proceso se utilizaron dos modelos, describiendo mejor los resultados el modelo no lineal pseudo segundo orden; se obtuvo un factor de correlación (R2) igual a 0.9998 y 0.9997 para 5 y 30 mg/L respectivamente. Para el líquido, la curva que describe mejor el equilibrio del sistema fue la Isoterma de Langmuir. Para este estudio se trabajó con un rango de concentraciones de 5 a 100 mg/L de plomo (II) obteniéndose una capacidad máxima de 53.476 mg/g. Por otro lado, para el equilibrio en el sólido se trabajó con la desorción del metal pesado y se encontró que el mejor eluyente capaz de liberar al plomo secuestrado de la pared celular del bioadsorbente fue el HNO3 a una concentración de 0.1 N. Finalmente, los resultados obtenidos en los ensayos pueden constatar que el bioadsorbente obtenido a partir de la especie Brassica Nigra seca es una buena alternativa para el tratamiento de aguas contaminadas con plomo

  • Evaluación de la adsorción de plomo (II) en soluciones acuosa utilizando como bioadsorbente la especie vegetal Brassica Nigra
    'Universidad Nacional de Ingenieria', 2018
    Co-Authors: Cadenas Vásquez, Walter Jesús
    Abstract:

    Currently, lead is one of the metals that has damaged different rivers of our country in recent years. Previously it is known that the family of the Brassica Nigra has obtained good results in phytoremediation of polluted soils with heavy metals, with this research we seek to take advantage of its stem and root to remove lead from aqueous solutions. First, the biomass was characterized with FTIR analysis to identify the main functional groups, the carboxyl functional group has been reported in different research works as a possible responsible for the attraction of heavy metals. In the second stage of the thesis, it was studied three operational variables, pH, particle size and biomass/solution ratio and the influence on adsorption was verified. It was worked in three levels of lead concentration, 5, 15 and 30 mg/L and it was found that the highest removal of the metal occurred at pH 5 due to the deprotonation of the carboxyl groups present in the wall cellular bioadsorbent. The results obtained in the adsorption capacities were 7,183, 20,833 and 27,042 mg/g for 5, 15 and 30 mg/L respectively. The granulometry of the biomass was between 177 and 297 microns with a biomass/solution ratio of 0.6 g/L, this values allowed succesful results to remove lead (II) from aqueous solutions. The solid - liquid system reaches the equilibrium after 600 minutes. To know the behavior of the kinetics of the process, two kinetic models were used, describing better the non-linear model pseudo second order results; the correlation factor (R2) were 0.9998 and 0.9997 for 5 and 30 mg/L respectively. The equilibrium in the liquid was described by Langmuir Isotherm. For this study the lead concentration range were between 5 to 100 mg/L, and the maximum capacity was 53,476 mg/g. On the other hand, the equilibrium in the solid was described by the desorption of lead (II) and the best eluent capable of releasing the lead from the cell wall of the bioadsorbent was HNO3 (0.1 N). Finally, the results from this research confirm that the bioadsorbent made from the Brassica Nigra is a good alternative to treat polluted water with lead.TesisActualmente, el plomo es uno de los metales que ha generado más daños en diversas regiones en los diferentes ríos de nuestro país en los últimos años. Anteriormente se conoce que la familia de la especie Brassica Nigra ha obtenido buenos resultados en la fitorremediación de suelos contaminados con metales pesados; con este trabajo de investigación se busca aprovechar su tallo y raíz para remover el plomo de soluciones acuosas. Primero se hicieron análisis para caracterizar a la biomasa como el análisis de FT-IR para identificar los principales grupos funcionales, encontrándose al grupo funcional carboxilo que ha sido reportado en diferentes trabajos de investigación como posible responsable de la atracción del metal pesado contaminante. En la segunda etapa del trabajo se hizo el estudio de tres variables operacionales, pH, tamaño de partícula y relación biomasa/solución y verificar su influencia en la adsorción. Se trabajó en tres niveles de concentración de plomo (II), 5, 15 y 30 mg/L y se encontró que la máxima remoción del metal ocurrió a un pH final igual a 5 debido a la desprotonación de los grupos carboxilo presente en la pared celular de la biomasa. Los resultados obtenidos en las capacidades de adsorción fueron 7.183, 20.833 y 27.042 mg/g para 5, 15 y 30 mg/L respectivamente. La granulometría de la biomasa estuvo en el rango de los 177 y 297 micrones con una relación de biomasa/solución de 0.6 g/L, que permitieron resultados satisfactorios en la remoción del plomo (II). El tiempo para que el sistema sólido – líquido alcance el equilibrio fue de 600 minutos, y para conocer el comportamiento de la cinética del proceso se utilizaron dos modelos, describiendo mejor los resultados el modelo no lineal pseudo segundo orden; se obtuvo un factor de correlación (R2) igual a 0.9998 y 0.9997 para 5 y 30 mg/L respectivamente. Para el líquido, la curva que describe mejor el equilibrio del sistema fue la Isoterma de Langmuir. Para este estudio se trabajó con un rango de concentraciones de 5 a 100 mg/L de plomo (II) obteniéndose una capacidad máxima de 53.476 mg/g. Por otro lado, para el equilibrio en el sólido se trabajó con la desorción del metal pesado y se encontró que el mejor eluyente capaz de liberar al plomo secuestrado de la pared celular del bioadsorbente fue el HNO3 a una concentración de 0.1 N. Finalmente, los resultados obtenidos en los ensayos pueden constatar que el bioadsorbente obtenido a partir de la especie Brassica Nigra seca es una buena alternativa para el tratamiento de aguas contaminadas con plomo

Christopher W. Simmons - One of the best experts on this subject based on the ideXlab platform.

  • assessment of two solid anaerobic digestate soil amendments for effects on soil quality and biosolarization efficacy
    Journal of Agricultural and Food Chemistry, 2017
    Co-Authors: Jesus D Fernandezbayo, James J. Stapleton, Jean S. Vandergheynst, Yigal Achmon, Duff R Harrold, Dlinka G Mccurry, Katie Hernandez, Ruth M Dahlquistwillard, Christopher W. Simmons
    Abstract:

    Anaerobic digestion is an organic waste bioconversion process that produces biofuel and digestates. Digestates have potential to be applied as soil amendment to improve properties for crop production including phytonutrient content and pest load. Our objective was to assess the impact of solid anaerobic digestates on weed seed inactivation and soil quality upon soil biosolarization (a pest control technique that combines solar heating and amendment-induced microbial activity). Two solid digestates from thermophilic (TD) and mesophilic (MD) digesters were tested. The solarized TD-amended samples presented significantly higher mortality of Brassica Nigra (71%, P = 0.032) than its equivalent incubated at room temperature. However, biosolarization with digestate amendment led to decreased weed seed mortality in certain treatments. The plant-available water, total C, and extractable P and K were significantly increased (P < 0.05) in the incubated amended soils. The results confirm the potential of digestates a...

  • effect of partially stabilized organic amendments on volatile acids production and pest inactivation using soil biosolarization
    2017 Spokane Washington July 16 - July 19 2017, 2017
    Co-Authors: Jesus D Fernandezbayo, James J. Stapleton, Yigal Achmon, Duff R Harrold, Ruth M Dahlquistwillard, Tara E Randall, Kelley V Hestmark, Thomas R Gordon, Christopher W. Simmons
    Abstract:

    Abstract. Soil biosolarization (SBS) is an enhanced soil disinfestation process, achieved by amending soil with organic matter (OM) prior to solarization. One reason for higher efficiency of SBS is the accumulation of volatile fatty acids (VFAs). The objective of this study was to assess the impact of partially stabilized organic wastes on SBS by monitoring the VFAs production kinetics and the inactivation of Fusarium oxysporum f.sp.lactucae (FOL) and Brassica Nigra. The amendments were organic wastes partially composted (PC) and partially digested (solid digestate –SD- and liquid digestate -LD). Soil mesocosms, non-amended and amended, were prepared with a soil already infested with FOL. Weed seeds were placed at 12.5 cm depth. The mesocosms were solarized in an experimental plot or incubated at room temperature (RT, 25ÂoC) for eight days. At 5 cm, FOL levels were below the detection limit (

  • Assessment of Two Solid Anaerobic Digestate Soil Amendments for Effects on Soil Quality and Biosolarization Efficacy
    2017
    Co-Authors: Jesús D. Fernández-bayo, James J. Stapleton, Jean S. Vandergheynst, Yigal Achmon, Duff R Harrold, Dlinka G Mccurry, Katie Hernandez, Ruth M. Dahlquist-willard, Christopher W. Simmons
    Abstract:

    Anaerobic digestion is an organic waste bioconversion process that produces biofuel and digestates. Digestates have potential to be applied as soil amendment to improve properties for crop production including phytonutrient content and pest load. Our objective was to assess the impact of solid anaerobic digestates on weed seed inactivation and soil quality upon soil biosolarization (a pest control technique that combines solar heating and amendment-induced microbial activity). Two solid digestates from thermophilic (TD) and mesophilic (MD) digesters were tested. The solarized TD-amended samples presented significantly higher mortality of Brassica Nigra (71%, P = 0.032) than its equivalent incubated at room temperature. However, biosolarization with digestate amendment led to decreased weed seed mortality in certain treatments. The plant-available water, total C, and extractable P and K were significantly increased (P < 0.05) in the incubated amended soils. The results confirm the potential of digestates as beneficial soil amendments. Further studies are needed to elucidate the impacts of digestate stability on biosolarization efficacy and soil properties

James J. Stapleton - One of the best experts on this subject based on the ideXlab platform.

  • assessment of two solid anaerobic digestate soil amendments for effects on soil quality and biosolarization efficacy
    Journal of Agricultural and Food Chemistry, 2017
    Co-Authors: Jesus D Fernandezbayo, James J. Stapleton, Jean S. Vandergheynst, Yigal Achmon, Duff R Harrold, Dlinka G Mccurry, Katie Hernandez, Ruth M Dahlquistwillard, Christopher W. Simmons
    Abstract:

    Anaerobic digestion is an organic waste bioconversion process that produces biofuel and digestates. Digestates have potential to be applied as soil amendment to improve properties for crop production including phytonutrient content and pest load. Our objective was to assess the impact of solid anaerobic digestates on weed seed inactivation and soil quality upon soil biosolarization (a pest control technique that combines solar heating and amendment-induced microbial activity). Two solid digestates from thermophilic (TD) and mesophilic (MD) digesters were tested. The solarized TD-amended samples presented significantly higher mortality of Brassica Nigra (71%, P = 0.032) than its equivalent incubated at room temperature. However, biosolarization with digestate amendment led to decreased weed seed mortality in certain treatments. The plant-available water, total C, and extractable P and K were significantly increased (P < 0.05) in the incubated amended soils. The results confirm the potential of digestates a...

  • effect of partially stabilized organic amendments on volatile acids production and pest inactivation using soil biosolarization
    2017 Spokane Washington July 16 - July 19 2017, 2017
    Co-Authors: Jesus D Fernandezbayo, James J. Stapleton, Yigal Achmon, Duff R Harrold, Ruth M Dahlquistwillard, Tara E Randall, Kelley V Hestmark, Thomas R Gordon, Christopher W. Simmons
    Abstract:

    Abstract. Soil biosolarization (SBS) is an enhanced soil disinfestation process, achieved by amending soil with organic matter (OM) prior to solarization. One reason for higher efficiency of SBS is the accumulation of volatile fatty acids (VFAs). The objective of this study was to assess the impact of partially stabilized organic wastes on SBS by monitoring the VFAs production kinetics and the inactivation of Fusarium oxysporum f.sp.lactucae (FOL) and Brassica Nigra. The amendments were organic wastes partially composted (PC) and partially digested (solid digestate –SD- and liquid digestate -LD). Soil mesocosms, non-amended and amended, were prepared with a soil already infested with FOL. Weed seeds were placed at 12.5 cm depth. The mesocosms were solarized in an experimental plot or incubated at room temperature (RT, 25ÂoC) for eight days. At 5 cm, FOL levels were below the detection limit (

  • Assessment of Two Solid Anaerobic Digestate Soil Amendments for Effects on Soil Quality and Biosolarization Efficacy
    2017
    Co-Authors: Jesús D. Fernández-bayo, James J. Stapleton, Jean S. Vandergheynst, Yigal Achmon, Duff R Harrold, Dlinka G Mccurry, Katie Hernandez, Ruth M. Dahlquist-willard, Christopher W. Simmons
    Abstract:

    Anaerobic digestion is an organic waste bioconversion process that produces biofuel and digestates. Digestates have potential to be applied as soil amendment to improve properties for crop production including phytonutrient content and pest load. Our objective was to assess the impact of solid anaerobic digestates on weed seed inactivation and soil quality upon soil biosolarization (a pest control technique that combines solar heating and amendment-induced microbial activity). Two solid digestates from thermophilic (TD) and mesophilic (MD) digesters were tested. The solarized TD-amended samples presented significantly higher mortality of Brassica Nigra (71%, P = 0.032) than its equivalent incubated at room temperature. However, biosolarization with digestate amendment led to decreased weed seed mortality in certain treatments. The plant-available water, total C, and extractable P and K were significantly increased (P < 0.05) in the incubated amended soils. The results confirm the potential of digestates as beneficial soil amendments. Further studies are needed to elucidate the impacts of digestate stability on biosolarization efficacy and soil properties

  • soil disinfestation with cruciferous amendments and sublethal heating effects on meloidogyne incognita sclerotium rolfsii and pythium ultimum
    Plant Pathology, 1998
    Co-Authors: James J. Stapleton, R A Duncan
    Abstract:

    Controlled environment experiments were carried out to test the effects of amending soil with fresh and dried residues of certain cultivated and noncultivated cruciferous plants, including Brassica Nigra, B. oleracea var. chinensis, B. oleracea var. italiensis, B. oleracea var. capitata, B. oleracea var. compacta and Raphanus sativus; and of a sublethal soil heating regime (38°C day/27°C night) on survival and activity of nematode and fungal plant pathogens including Meloidogyne incognita, Sclerotium rolfsii and Pythium ultimum. Addition of the various cruciferous amendments to soil without heating resulted in significantly reduced tomato root galling (38-100%) by M. incognita or reduced recovery of active fungal pathogens (0-100%) after 7 days incubation. When cruciferous soil amendments were combined with the sublethal heating regime, nematode galling was reduced by 95-100%, and recovery of active fungi was reduced by 85-100%. No differences were found between fresh or dried cruciferous residues.

Christelle Bonnet - One of the best experts on this subject based on the ideXlab platform.

  • Combined biotic stresses trigger similar transcriptomic responses but contrasting resistance against a chewing herbivore in Brassica Nigra
    BMC Plant Biology, 2017
    Co-Authors: Christelle Bonnet, Steve Lassueur, Camille Ponzio, Rieta Gols, Marcel Dicke
    Abstract:

    BackgroundIn nature, plants are frequently exposed to simultaneous biotic stresses that activate distinct and often antagonistic defense signaling pathways. How plants integrate this information and whether they prioritize one stress over the other is not well understood.ResultsWe investigated the transcriptome signature of the wild annual crucifer, Brassica Nigra, in response to eggs and caterpillars of Pieris Brassicae butterflies, Brevicoryne Brassicae aphids and the bacterial phytopathogen Xanthomonas campestris pv. raphani (Xcr). Pretreatment with egg extract, aphids, or Xcr had a weak impact on the subsequent transcriptome profile of plants challenged with caterpillars, suggesting that the second stress dominates the transcriptional response. Nevertheless, P. Brassicae larval performance was strongly affected by egg extract or Xcr pretreatment and depended on the site where the initial stress was applied. Although egg extract and Xcr pretreatments inhibited insect-induced defense gene expression, suggesting salicylic acid (SA)/jasmonic acid (JA) pathway cross talk, this was not strictly correlated with larval performance.ConclusionThese results emphasize the need to better integrate plant responses at different levels of biological organization and to consider localized effects in order to predict the consequence of multiple stresses on plant resistance.