The Experts below are selected from a list of 723 Experts worldwide ranked by ideXlab platform
Klaas Vrieling - One of the best experts on this subject based on the ideXlab platform.
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Evolutionary changes in growth, regrowth and carbohydrate storage in an invasive plant
Nature Publishing Group, 2018Co-Authors: Tiantian Lin, Peter G. L. Klinkhamer, Klaas VrielingAbstract:Abstract We hypothesized that due to the absence of specialist herbivores in introduced ranges, invasive plants have evolved decreased allocation to carbohydrate storage for regrowth ability and as a consequence allocate more to growth. In this study, we compared plant growth, carbohydrate storage and regrowth ability of invasive and native Jacobaea vulgaris in response to complete shoot defoliation. We used invasive J. vulgaris genotypes from three geographically and climactically distinct regions and compared these with native genotypes from Europe. We found that invasive genotypes initially grew larger while native genotypes regrew larger after defoliation. Before defoliation, the carbohydrate storage in roots of invasive genotypes was 38% lower than native genotypes. Biomass after regrowth increased with root carbohydrate storage while it decreased with structural root mass, showing that it is crucial to study root storage and structural components separately in order to investigate plant regrowth. All studied traits of invasive populations from the three geographically and climatologically distinct regions changed in the same expected direction suggesting that the shifts in herbivore guild were causal to the observed change in growth and regrowth ability rather than environmental factors
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Local adaptation in oviposition choice of a specialist herbivore: The cinnabar moth
Acta Oecologica, 2017Co-Authors: Xianqin Wei, Patrick P.j. Mulder, Klaas Vrieling, Peter G. L. KlinkhamerAbstract:Abstract Specialist herbivores feed on a restricted number of related plant species and may suffer food shortage if overexploitation leads to periodic defoliation of their food plants. The density, size and quality of food plants are important factors that determine the host plant choice of specialist herbivores. To explore how all these factors influence their oviposition behaviour, we used the cinnabar moth Tyria Jacobaeae and the hybrids of a cross between Jacobaea vulgaris and J. aquatica as a study system. While defoliation by the cinnabar moth is common in the coastal area of The Netherlands, it is relatively rare in inland ragwort population. Ragworts contain pyrrolizidine alkaloids (PAs) and those that are found in coastal areas are rich in jacobine-like PAs while those that occur inland are rich in erucifoline-like PAs. We tested how the oviposition preference was influenced by plant size, nitrogen and water content and PA composition. We used cinnabar moth populations from a regularly defoliated area, Meijendel, and Bertogne, a rarely defoliated area. Our results revealed no effects of nitrogen or water content on oviposition preference. Moths from both populations laid larger egg batches on the plants rich in jacobine-like PAs. Moths from Meijendel preferred larger plants and spread their eggs over more egg batches that were, on average, smaller than those of Bertogne moths. These results suggest that Meijendel moths adopted a oviposition strategy to cope with potential defoliation.
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Interactions between Plant Metabolites Affect Herbivores: A Study with Pyrrolizidine Alkaloids and Chlorogenic Acid
Frontiers Media S.A., 2017Co-Authors: Xiaojie Liu, Klaas Vrieling, Peter G. L. KlinkhamerAbstract:The high structural diversity of plant metabolites suggests that interactions among them should be common. We investigated the effects of single metabolites and combinations of plant metabolites on insect herbivores. In particular we studied the interacting effects of pyrrolizidine alkaloid (PAs), and chlorogenic acid (CGA), on a generalist herbivore, Frankliniella occidentalis. We studied both the predominantly occurring PA N-oxides and the less frequent PA free bases. We found antagonistic effects between CGA and PA free bases on thrips mortality. In contrast PA N-oxides showed synergistic interactions with CGA. PA free bases caused a higher thrips mortality than PA N-oxides while the reverse was through for PAs in combination with CGA. Our results provide an explanation for the predominate storage of PA N-oxides in plants. We propose that antagonistic interactions represent a constraint on the accumulation of plant metabolites, as we found here for Jacobaea vulgaris. The results show that the bioactivity of a given metabolite is not merely dependent upon the amount and chemical structure of that metabolite, but also on the co-occurrence metabolites in, e.g., plant cells, tissues and organs. The significance of this study is beyond the concerns of the two specific groups tested here. The current study is one of the few studies so far that experimentally support the general conception that the interactions among plant metabolites are of great importance to plant-environment interactions
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Testing the Generalist-Specialist Dilemma: The Role of Pyrrolizidine Alkaloids in Resistance to Invertebrate Herbivores in Jacobaea Species
2016Co-Authors: Xianqin Wei, Patrick P.j. Mulder, Klaas Vrieling, Peter G. L. KlinkhamerAbstract:Abstract Plants produce a diversity of secondary metabolites (SMs) to protect them from generalist herbivores. On the other hand, specialist herbivores use SMs for host plant recognition, feeding and oviposition cues, and even sequester SMs for their own defense. Therefore, plants are assumed to face an evolu-tionary dilemma stemming from the contrasting effects of generalist and specialist herbivores on SMs. To test this hy-pothesis, bioassays were performed with F2 hybrids from Jacobaea species segregating for their pyrrolizidine alkaloids (PAs), using a specialist flea beetle (Longitarsus Jacobaeae) and a generalist slug (Deroceras invadens). Our study dem-onstrated that while slug feeding damage was negatively cor-related with the concentration of total PAs and that of senecionine-like PAs, flea beetle feeding damage was not af-fected by PAs. It was positively correlated though, with leaf fresh weight. The generalist slug was deterred by senecionine-like PAs but the specialist flea beetle was adapted to PAs in its host plant. Testing other herbivores in the same plant system, it was observed that the egg number of the specialist cinnabar moth was positively correlated with jacobine-like PAs, while the silver damage of generalist thrips was negatively correlat-ed with senecionine- and jacobine-like PAs, and the pupae number of generalist leaf miner was negatively correlated with otosenine-like PAs. Therefore, while the specialist herbivores showed no correlation whatsoever with PA concentration, the generalist herbivores all showed a negative correlation with at least one type of PA. We concluded that the generalist herbi-vores were deterred by different structural groups of PAs while the specialist herbivores were attracted or adapted to PAs in its host plants. Keywords Secondary metabolites diversity. F2 hybrids. Deroceras invadens. Longitarsus Jacobaeae. Jacobaea vulgaris. Feeding damag
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Are effects of common ragwort in the Ames test caused by pyrrolizidine alkaloids
Mutation Research, 2015Co-Authors: Toine F.h. Bovee, Peter G. L. Klinkhamer, Richard J.r. Helsdingen, Ron Laurentius Hoogenboom, Monique De Nijs, Xiaojie Liu, Klaas Vrieling, Ad A. C. M. Peijnenburg, Patrick P.j. MulderAbstract:It has previously been demonstrated by others that acetone extracts of Senecio Jacobaea (syn. Jacobaea vulgaris, common or tansy ragwort) test positive in the Salmonella/microsome mutagenicity test (Ames test). Pyrrolizidine alkaloids (PAs) are thought to be responsible for these mutagenic effects. However, it was also observed that the major PA present in common ragwort, jacobine, produced a negative response (with and without the addition of rat liver S9) in Salmonella test strains TA98, TA100, TA1535 and TA1537. To investigate which compounds in the plant extracts were responsible for the positive outcome, the present study investigated the contents and mutagenic effects of methanol and acetone extracts prepared from dried ground S. Jacobaea and Senecio inaequidens (narrow-leafed ragwort). Subsequently, a fractionation approach was set up in combination with LC-MS/MS analysis of the fractions. It was shown that the positive Ames test outcomes of S. Jacobaea extracts are unlikely to be caused by PAs, but rather by the flavonoid quercetin. This study also demonstrates the importance of identifying compounds responsible for positive test results in bioassays.
Patrick P.j. Mulder - One of the best experts on this subject based on the ideXlab platform.
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Removal of soil biota alters soil feedback effects on plant growth and defense chemistry.
The New phytologist, 2018Co-Authors: Minggang Wang, Patrick P.j. Mulder, Wim H. Van Der Putten, Weibin Ruan, Olga Kostenko, Sabrina Carvalho, S. Emilia Hannula, T. Martijn BezemerAbstract:We examined how the removal of soil biota affects plant–soil feedback (PSF) and defense chemistry of Jacobaea vulgaris, an outbreak plant species in Europe containing the defense compounds pyrrolizidine alkaloids (PAs). Macrofauna and mesofauna, as well as fungi and bacteria, were removed size selectively from unplanted soil or soil planted with J. vulgaris exposed or not to above‐ or belowground insect herbivores. Wet‐sieved fractions, using 1000‐, 20‐, 5‐ and 0.2‐μm mesh sizes, were added to sterilized soil and new plants were grown. Sieving treatments were verified by molecular analysis of the inocula. In the feedback phase, plant biomass was lowest in soils with 1000‐ and 20‐μm inocula, and soils conditioned with plants gave more negative feedback than without plants. Remarkably, part of this negative PSF effect remained present in the 0.2‐μm inoculum where no bacteria were present. PA concentration and composition of plants with 1000‐ or 20‐μm inocula differed from those with 5‐ or 0.2‐μm inocula, but only if soils had been conditioned by undamaged plants or plants damaged by aboveground herbivores. These effects correlated with leaf hyperspectral reflectance. We conclude that size‐selective removal of soil biota altered PSFs, but that these PSFs were also influenced by herbivory during the conditioning phase.
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Local adaptation in oviposition choice of a specialist herbivore: The cinnabar moth
Acta Oecologica, 2017Co-Authors: Xianqin Wei, Patrick P.j. Mulder, Klaas Vrieling, Peter G. L. KlinkhamerAbstract:Abstract Specialist herbivores feed on a restricted number of related plant species and may suffer food shortage if overexploitation leads to periodic defoliation of their food plants. The density, size and quality of food plants are important factors that determine the host plant choice of specialist herbivores. To explore how all these factors influence their oviposition behaviour, we used the cinnabar moth Tyria Jacobaeae and the hybrids of a cross between Jacobaea vulgaris and J. aquatica as a study system. While defoliation by the cinnabar moth is common in the coastal area of The Netherlands, it is relatively rare in inland ragwort population. Ragworts contain pyrrolizidine alkaloids (PAs) and those that are found in coastal areas are rich in jacobine-like PAs while those that occur inland are rich in erucifoline-like PAs. We tested how the oviposition preference was influenced by plant size, nitrogen and water content and PA composition. We used cinnabar moth populations from a regularly defoliated area, Meijendel, and Bertogne, a rarely defoliated area. Our results revealed no effects of nitrogen or water content on oviposition preference. Moths from both populations laid larger egg batches on the plants rich in jacobine-like PAs. Moths from Meijendel preferred larger plants and spread their eggs over more egg batches that were, on average, smaller than those of Bertogne moths. These results suggest that Meijendel moths adopted a oviposition strategy to cope with potential defoliation.
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Testing the Generalist-Specialist Dilemma: The Role of Pyrrolizidine Alkaloids in Resistance to Invertebrate Herbivores in Jacobaea Species
2016Co-Authors: Xianqin Wei, Patrick P.j. Mulder, Klaas Vrieling, Peter G. L. KlinkhamerAbstract:Abstract Plants produce a diversity of secondary metabolites (SMs) to protect them from generalist herbivores. On the other hand, specialist herbivores use SMs for host plant recognition, feeding and oviposition cues, and even sequester SMs for their own defense. Therefore, plants are assumed to face an evolu-tionary dilemma stemming from the contrasting effects of generalist and specialist herbivores on SMs. To test this hy-pothesis, bioassays were performed with F2 hybrids from Jacobaea species segregating for their pyrrolizidine alkaloids (PAs), using a specialist flea beetle (Longitarsus Jacobaeae) and a generalist slug (Deroceras invadens). Our study dem-onstrated that while slug feeding damage was negatively cor-related with the concentration of total PAs and that of senecionine-like PAs, flea beetle feeding damage was not af-fected by PAs. It was positively correlated though, with leaf fresh weight. The generalist slug was deterred by senecionine-like PAs but the specialist flea beetle was adapted to PAs in its host plant. Testing other herbivores in the same plant system, it was observed that the egg number of the specialist cinnabar moth was positively correlated with jacobine-like PAs, while the silver damage of generalist thrips was negatively correlat-ed with senecionine- and jacobine-like PAs, and the pupae number of generalist leaf miner was negatively correlated with otosenine-like PAs. Therefore, while the specialist herbivores showed no correlation whatsoever with PA concentration, the generalist herbivores all showed a negative correlation with at least one type of PA. We concluded that the generalist herbi-vores were deterred by different structural groups of PAs while the specialist herbivores were attracted or adapted to PAs in its host plants. Keywords Secondary metabolites diversity. F2 hybrids. Deroceras invadens. Longitarsus Jacobaeae. Jacobaea vulgaris. Feeding damag
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Data_Kos et al_Journal of Ecology 2015.xlsx
2016Co-Authors: Martine Kos, Patrick P.j. Mulder, Maarten A B Tuijl, Joris De Roo, Martijn T BezemerAbstract:In a greenhouse experiment, we grew Jacobaea vulgaris plants in soil conditioned by 10 plant species, in a multispecies mixture, or in unconditioned (mixed field) soil. For all soils, we measured fungal community composition For each plant, we recorded biomass, chemistry (amino acids and pyrrolizidine alkaloids (PA) in phloem exudates), performance of a specialist and a generalist aphid Biomass and chemistry were measured at 2 sampling times: 6 and 13 weeks after transplanting in the conditioned soil
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Are effects of common ragwort in the Ames test caused by pyrrolizidine alkaloids
Mutation Research, 2015Co-Authors: Toine F.h. Bovee, Peter G. L. Klinkhamer, Richard J.r. Helsdingen, Ron Laurentius Hoogenboom, Monique De Nijs, Xiaojie Liu, Klaas Vrieling, Ad A. C. M. Peijnenburg, Patrick P.j. MulderAbstract:It has previously been demonstrated by others that acetone extracts of Senecio Jacobaea (syn. Jacobaea vulgaris, common or tansy ragwort) test positive in the Salmonella/microsome mutagenicity test (Ames test). Pyrrolizidine alkaloids (PAs) are thought to be responsible for these mutagenic effects. However, it was also observed that the major PA present in common ragwort, jacobine, produced a negative response (with and without the addition of rat liver S9) in Salmonella test strains TA98, TA100, TA1535 and TA1537. To investigate which compounds in the plant extracts were responsible for the positive outcome, the present study investigated the contents and mutagenic effects of methanol and acetone extracts prepared from dried ground S. Jacobaea and Senecio inaequidens (narrow-leafed ragwort). Subsequently, a fractionation approach was set up in combination with LC-MS/MS analysis of the fractions. It was shown that the positive Ames test outcomes of S. Jacobaea extracts are unlikely to be caused by PAs, but rather by the flavonoid quercetin. This study also demonstrates the importance of identifying compounds responsible for positive test results in bioassays.
Martijn T Bezemer - One of the best experts on this subject based on the ideXlab platform.
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microbiomes of a specialist caterpillar are consistent across different habitats but also resemble the local soil microbial communities
Animal Microbiome, 2020Co-Authors: Sofia I F Gomes, Robin Heinen, Jonathan R De Long, Renske Jongen, Emilia S Hannula, Anna M Kielak, Ivor Keesmaat, Martijn T BezemerAbstract:Insect-associated microorganisms can provide a wide range of benefits to their host, but insect dependency on these microbes varies greatly. The origin and functionality of insect microbiomes is not well understood. Many caterpillars can harbor symbionts in their gut that impact host metabolism, nutrient uptake and pathogen protection. Despite our lack of knowledge on the ecological factors driving microbiome assemblages of wild caterpillars, they seem to be highly variable and influenced by diet and environment. Several recent studies have shown that shoot-feeding caterpillars acquire part of their microbiome from the soil. Here, we examine microbiomes of a monophagous caterpillar (Tyria Jacobaeae) collected from their natural host plant (Jacobaea vulgaris) growing in three different environments: coastal dunes, natural inland grasslands and riverine grasslands, and compare the bacterial communities of the wild caterpillars to those of soil samples collected from underneath each of the host plants from which the caterpillars were collected. The microbiomes of the caterpillars were dominated by Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. Only 5% of the total bacterial diversity represented 86.2% of the total caterpillar’s microbiome. Interestingly, we found a high consistency of dominant bacteria within the family Burkholderiaceae in all caterpillar samples across the three habitats. There was one amplicon sequence variant belonging to the genus Ralstonia that represented on average 53% of total community composition across all caterpillars. On average, one quarter of the caterpillar microbiome was shared with the soil. We found that the monophagous caterpillars collected from fields located more than 100 km apart were all dominated by a single Ralstonia. The remainder of the bacterial communities that were present resembled the local microbial communities in the soil in which the host plant was growing. Our findings provide an example of a caterpillar that has just a few key associated bacteria, but that also contains a community of low abundant bacteria characteristic of soil communities.
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exogenous application of plant hormones in the field alters aboveground plant insect responses and belowground nutrient availability but does not lead to differences in plant soil feedbacks
Arthropod-plant Interactions, 2020Co-Authors: Jeffrey A. Harvey, Robin Heinen, Katja Steinauer, Jonathan R De Long, Renske Jongen, Arjen Biere, Martijn T BezemerAbstract:Plant–soil feedbacks of plants that are exposed to herbivory have been shown to differ from those of plants that are not exposed to herbivores. Likely, this process is mediated by jasmonic acid (JA) and salicylic acid (SA) defense pathways, which are induced by aboveground herbivory. Furthermore, exogenous application of these phytohormones to plants alters belowground communities, but whether this changes plant–soil feedbacks in natural systems is unknown. We applied exogenous sprays of JA and SA individually and in combination to field plots in a restored grassland. Control plots were sprayed with demineralized water. After three repeated application rounds, we transplanted seedlings of the plant–soil feedback model plant Jacobaea vulgaris as phytometer plants to test the effects of potential phytohormone-mediated changes in the soil, on plant performance during the response phase. We further measured how exogenous application of phytohormones altered plant-related ecosystem characteristics (plot-level); soil chemistry, plot productivity, insect communities and predation. Biomass of the phytometer plants only co-varied with plot productivity, but was not influenced by phytohormone applications. However, we did observe compound-specific effects of SA application on insect communities, most notably on parasitoid attraction, and of JA application on soil nitrogen levels. Although we did not find effects on plant–soil feedbacks, the effects of exogenous application of phytohormones did alter other ecosystem-level processes related to soil nutrient cycling, which may lead to legacy effects in the longer term. Furthermore, exogenous application of phytohormones led to altered attraction of specific insect groups.
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home and away litter decomposition depends on the size fractions of the soil biotic community
Soil Biology & Biochemistry, 2020Co-Authors: Yingbin Li, G F Veen, Simon Vandenbrande, Emilia S Hannula, Freddy Ten C Hooven, Qi Li, Wenju Liang, Martijn T BezemerAbstract:Abstract The ‘home-field advantage’ (HFA) hypothesis predicts that litter decomposition is accelerated in its home environment (i.e. in conspecific soil). Soil organisms play a key role in driving such HFA effects. Soil biota have a large range of body sizes, referred to as size fractions, which may influence their roles in the decomposition process and in the generation of HFA effects. However, how HFA effects depend on the different size fractions of the soil biotic community is unknown. We conducted a microcosm decomposition experiment to examine how size fractions of the soil biotic community affected litter decomposition and HFA effects. In a semi-natural grassland in the Netherlands, we collected leaf litter and soil from two abundant forbs: Tanacetum vulgare and Jacobaea vulgaris. Watery extracts of the soils were sieved through differently-meshed sieves (ranging from 850 μm to 6 μm) to obtain soil communities of different size fractions. Microcosms were inoculated with these different size fractions of the soil biotic community and we examined their effects on microbial composition, litter mass loss and HFA effects. Three months after inoculation, the diversity of the fungal community in the inoculated pots decreased with decreasing size fractions of the soil biotic community. Similarly, litter mass loss also decreased with decreasing soil biotic community size. In contrast, the HFA effect increased with decreasing size fractions of the soil biotic community, but these differences disappeared after six months of decomposition. Our results indicate that soil microorganisms, mainly the smallest size fractions, are specialized to decompose specific resources and thus promote HFA effects, but that their effect is only apparent during specific stages of litter decomposition.
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Data_Kos et al_Journal of Ecology 2015.xlsx
2016Co-Authors: Martine Kos, Patrick P.j. Mulder, Maarten A B Tuijl, Joris De Roo, Martijn T BezemerAbstract:In a greenhouse experiment, we grew Jacobaea vulgaris plants in soil conditioned by 10 plant species, in a multispecies mixture, or in unconditioned (mixed field) soil. For all soils, we measured fungal community composition For each plant, we recorded biomass, chemistry (amino acids and pyrrolizidine alkaloids (PA) in phloem exudates), performance of a specialist and a generalist aphid Biomass and chemistry were measured at 2 sampling times: 6 and 13 weeks after transplanting in the conditioned soil
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plant soil feedback effects on plant quality and performance of an aboveground herbivore interact with fertilisation
Oikos, 2015Co-Authors: Martine Kos, Patrick P.j. Mulder, J. Roo, Maarten A B Tuijl, Martijn T BezemerAbstract:Plant–soil feedback (PSF) effects on plant performance can be influenced by the availability of nutrients in the soil. Recent studies have shown that PSF effects can also change aboveground plant–insect interactions via soil-mediated changes in plant quality, but whether this is influenced by soil nutrient availability is unknown. We examined how fertilisation influences PSF effects on aboveground plant-aphid interactions in ragwort Jacobaea vulgaris. We grew J. vulgaris in soil conditioned by conspecific plants and in unconditioned soil at two levels of fertilisation and measured soil fungal communities, plant biomass, concentrations of primary (amino acids) and secondary (pyrrolizidine alkaloids; PAs) metabolites in phloem exudates, performance of the specialist aphid Aphis Jacobaeae and sequestration of PAs by the aphid. We observed a strong interaction between soil conditioning and fertilisation on amino acid and PA concentrations in phloem exudates of J. vulgaris and on aphid performance, with opposite effects of soil conditioning at the two fertilisation levels. Plant biomass was reduced by soil conditioning and increased by fertilisation. Aphids contained high PA concentrations, converted N-oxides into tertiary amines and preferentially sequestered certain PA compounds, but PA sequestration was not affected by any of the treatments. We conclude that effects of PSF and fertilisation on plant chemistry and aphid performance are interdependent. Our study highlights the need to consider the importance of abiotic soil conditions on the outcome of PSF effects on aboveground plant–insect interactions.
Bezemer T.m. - One of the best experts on this subject based on the ideXlab platform.
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Exogenous application of plant defense hormones alters the effects of live soils on plant performance
'Elsevier BV', 2021Co-Authors: Zhang Jing, Vrieling Klaas, Klinkhamer, Peter G.l., Bezemer T.m.Abstract:The overall effect of a live soil inoculum collected from nature on plant biomass is often negative. One hypothesis to explain this phenomenon is that the overall net pathogenic effect of soil microbial communities reduces plant performance. Induced plant defenses triggered by the application of the plant hormones jasmonic acid (JA) and salicylic acid (SA) may help to mitigate this pathogenic effect of live soil. However, little is known about how such hormonal application to the plant affects the soil and how this, in turn, impacts plant growth. We grew four plant species in sterilized and inoculated live soil and exposed their leaves to two hormonal treatments (JA and SA). Two species (Jacobaea vulgaris and Cirsium vulgare) were negatively affected by soil inoculation. In these two species foliar application of SA increased biomass in live soil but not in sterilized soil. Two other species (Trifolium repens and Daucus carota) were not affected by soil inoculum and for these two species foliar application of SA reduced plant biomass in both the sterilized and live soil. Application of JA reduced plant biomass in both soils for all species. We subsequently carried out a multiple generation experiment for one of the plant species, J. vulgaris. In each generation, the live soil was a mixture of 10% soil from the previous generation and 90% sterilized soil and the same hormonal treatments were applied. The negative effects of live soil on plant biomass were similar in all four generations, and this negative effect was mitigated by the application of SA. Our research suggests that the application of SA can mitigate the negative effects of live soil on plant growth. Although the inoculum of soil containing a natural live soil microbial community had a strong negative effect on the growth of J. vulgaris, we found no evidence for an increase or decrease in negative plant-soil feedback in either the control or the SA treated plants. Also plant performance did not decrease consistently with succeeding generations
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Soil Inoculation Alters Leaf Metabolic Profiles in Genetically Identical Plants
'Springer Science and Business Media LLC', 2020Co-Authors: Martis B., Kampen J. Van, Choi Y.h., Vrieling K., Klinkhamer P.g.l., Bezemer T.m.Abstract:Abiotic and biotic properties of soil can influence growth and chemical composition of plants. Although it is well-known that soil microbial composition can vary greatly spatially, how this variation affects plant chemical composition is poorly understood. We grew genetically identical Jacobaea vulgaris in sterilized soil inoculated with live soil collected from four natural grasslands and in 100% sterilized soil. Within each grassland we sampled eight plots, totalling 32 different inocula. Two samples per plot were collected, leading to three levels of spatial variation: within plot, between and within grasslands. The leaf metabolome was analysed with 1H Nuclear magnetic resonance spectroscopy (NMR) to investigate if inoculation altered the metabolome of plants and how this varied between and within grasslands. Inoculation led to changes in metabolomics profiles of J. vulgaris in two out of four sites. Plants grown in sterilized and inoculated soils differed in concentrations of malic acid, tyrosine, trehalose and two pyrrolizidine alkaloids (PA). Metabolomes of plants grown in inoculated soils from different sites varied in glucose, malic acid, trehalose, tyrosine and in one PA. The metabolome of plants grown in soils with inocula from the same site was more similar than with inocula from distant sites. We show that soil influences leaf metabolomes. Performance of aboveground insects often depends on chemical composition of plants. Hence our results imply that soil microbial communities, via affecting aboveground plant metabolomes, can impact aboveground plant-insect food chains but that it is difficult to make general predictions due to spatial variation in soil microbiomes.Plant science
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Temporal carry-over effects in sequential plant–soil feedbacks
2018Co-Authors: Wubs E.r.j., Bezemer T.m.Abstract:Plant–soil feedbacks (PSF) strongly influence plant performance. However, to what extent these PSF effects are persistent in the soil and how they are altered by species th at subsequently condition the soil is unclear. Here we test how conspecific and heterospecific soil-conditioning effects interact across different soil-conditioning phases. We conducted a fully factorial glasshouse experiment where six plant species conditioned soils in two consecutive phases and measured the performance of Jacobaea vulgaris. The species that conditioned the soil during the second conditioning phase strongly determined the performance of J. vulgaris, but also the order and combination of species that conditioned the soil in the two phases accounted for a large part of the variance. For shoot biomass this interaction was the dominant variance component. We show that soil conditioning legacies carry-over and interact with the conditioning effects of succeeding plants. In the field, species replacements at the patch level often appear to be unpredictable and we suggest that sequential feedbacks may explain these apparently unpredictable transitions
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Plant competition alters the temporal dynamics of plant-soil feedbacks
2018Co-Authors: Bezemer T.m., Jing Jingying, Bakx-schotman J.m.t., Bijleveld Erik-janAbstract:Most studies on plant‐soil feedback (PSF) and plant competition measure the feedback response at one moment only. However, PSFs and competition may both change over time, and how PSF and competition interact over time is unclear. We tested the temporal dynamics of PSF and interspecific competition for the forb Jacobaea vulgaris and the grass Holcus lanatus. We grew both species individually and in interspecific competition in soil that was first conditioned in the greenhouse by J. vulgaris, by H. lanatus or without plant growth. For a period of 11 weeks, we harvested plants twice a week and analysed the fungal and chemical composition of the different soils at the end of the first and second growth phase. During the second growth phase, when grown in isolation, both species produced more biomass in heterospecific conditioned soil than in conspecific conditioned soil. Young J. vulgaris exhibited a strong negative conspecific feedback, but this effect diminished over time and became neutral in older plants. In contrast, when grown in competition, the negative conspecific feedback of J. vulgaris exacerbated over time. Older H. lanatus plants benefited more from heterospecific conditioning when competing with J. vulgaris, then when grown isolated. Fungal community composition and soil chemistry differed significantly between soils but this was mainly driven by differences between plant‐conditioned and unconditioned soils. Remarkably, at the end of the second growth phase, fungal community composition was not explained by the legacy of the species that had been grown in the soil most recently, but still reflected the legacy of the first growth phase. We reexamined plant growth during a third growth phase. Biomass of J. vulgaris was still influenced by the treatments imposed during the first phase, while H. lanatus responded only to the plant growth treatments imposed during the second phase. Synthesis. Our study shows that the direction and magnitude of PSF depends on plant age and competition, and also on soil legacy effects of earlier plant growth. These results highlight the need to incorporate dynamic PSFs in research on plant populations and communities
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Effects of plant diversity on the concentration of secondary plant metabolites and the density of arthropods on focal plants in the field
2017Co-Authors: Kostenko O., Mulder, Patrick P.j., Courbois Matthijs, Bezemer T.m.Abstract:The diversity of the surrounding plant community can directly affect the abundance of insects on a focal plant as well as the size and quality of that focal plant. However, to what extent the effects of plant diversity on the arthropod community on a focal plant are mediated by host plant quality or by the diversity of the surrounding plants remains unresolved. In the field, we sampled arthropod communities on focal Jacobaea vulgaris plants growing in experimental plant communities that were maintained at different levels of diversity (one, two, four or nine species) for 3 years. Focal plants were also planted in plots without surrounding vegetation. We recorded the structural characteristics of each of the surrounding plant communities as well as the growth, and primary and secondary chemistry (pyrrolizidine alkaloids, PAs) of the focal plants to disentangle the potential mechanisms causing the diversity effects. Two years after planting, the abundance of arthropods on focal plants that were still in the vegetative stage decreased with increasing plant diversity, while the abundance of arthropods on reproductive focal plants was not significantly affected by the diversity of the neighbouring community. The size of both vegetative and reproductive focal plants was not significantly affected by the diversity of the neighbouring community, but the levels of PAs and the foliar N concentration of vegetative focal plants decreased with increasing plant diversity. Structural equation modelling revealed that the effects of plant diversity on the arthropod communities on focal plants were not mediated by changes in plant quality. Synthesis. Plant quality can greatly influence insect preference and performance. However, under natural conditions, the effects of the neighbouring plant community can overrule the plant quality effects of individual plants growing in those communities on the abundance of insects associated to this plant.
Wim H. Van Der Putten - One of the best experts on this subject based on the ideXlab platform.
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Removal of soil biota alters soil feedback effects on plant growth and defense chemistry.
The New phytologist, 2018Co-Authors: Minggang Wang, Patrick P.j. Mulder, Wim H. Van Der Putten, Weibin Ruan, Olga Kostenko, Sabrina Carvalho, S. Emilia Hannula, T. Martijn BezemerAbstract:We examined how the removal of soil biota affects plant–soil feedback (PSF) and defense chemistry of Jacobaea vulgaris, an outbreak plant species in Europe containing the defense compounds pyrrolizidine alkaloids (PAs). Macrofauna and mesofauna, as well as fungi and bacteria, were removed size selectively from unplanted soil or soil planted with J. vulgaris exposed or not to above‐ or belowground insect herbivores. Wet‐sieved fractions, using 1000‐, 20‐, 5‐ and 0.2‐μm mesh sizes, were added to sterilized soil and new plants were grown. Sieving treatments were verified by molecular analysis of the inocula. In the feedback phase, plant biomass was lowest in soils with 1000‐ and 20‐μm inocula, and soils conditioned with plants gave more negative feedback than without plants. Remarkably, part of this negative PSF effect remained present in the 0.2‐μm inoculum where no bacteria were present. PA concentration and composition of plants with 1000‐ or 20‐μm inocula differed from those with 5‐ or 0.2‐μm inocula, but only if soils had been conditioned by undamaged plants or plants damaged by aboveground herbivores. These effects correlated with leaf hyperspectral reflectance. We conclude that size‐selective removal of soil biota altered PSFs, but that these PSFs were also influenced by herbivory during the conditioning phase.
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chemical variation in Jacobaea vulgaris is influenced by the interaction of season and vegetation successional stage
Phytochemistry, 2014Co-Authors: Sabrina Carvalho, Patrick P.j. Mulder, Mirka Macel, Andrew K Skidmore, Wim H. Van Der PuttenAbstract:Knowledge on spatio-temporal dynamics of plant primary and secondary chemistry under natural conditions is important to assess how plant defence varies in real field conditions. Plant primary and secondary chemistry is known to vary with both season and vegetation successional stage, however, in few studies these two sources of variation have been examined in combination. Here we examine variations in primary and secondary chemistry of Jacobaea vulgaris (Asteraceae) throughout the growing season in early, mid, and late stages of secondary succession following land abandonment using a well-established chronosequence in The Netherlands. We investigated primary and secondary chemistry of both leaves and flowers, in order to determine if patterns during seasonal (phenological) development may differ among successional stages. The chemical concentration of primary and secondary chemistry compounds in J. vulgaris varied throughout the season and was affected by vegetation succession stage. Concentrations of pyrrolizidine alkaloid (PA) tertiary-amines were highest in flowers during early Summer and in fields that had been abandoned ten to twenty years ago. PA N-oxide concentrations of both leaves and flowers, on the other hand increased with the progression of both season and succession. In Spring and early Summer chlorophyll concentrations were highest, especially in the oldest fields of the chronosequence. During phenological development, nitrogen concentration increased in flowers and decreased in leaves revealing allocation of nutrients from vegetative to reproductive plant parts throughout the growing season. The highest concentrations of N-oxides and chlorophylls were detected in older fields. Thus, our results suggest that variations in plant patterns of nutritional and defence compounds throughout the growing season are depending on successional context.
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above and below ground herbivory effects on below ground plant fungus interactions and plant soil feedback responses
Journal of Ecology, 2013Co-Authors: Martijn T Bezemer, Patrick P.j. Mulder, Wim H. Van Der Putten, Tess F J Van De Voorde, Henk Martens, Olga KostenkoAbstract:1.Feeding by insect herbivores can affect plant growth and the concentration of defense compounds in plant tissues. Since plants provide resources for soil organisms, herbivory can also influence the composition of the soil community via its effects on the plant. Soil organisms, in turn, are important for plant growth. We tested whether insect herbivores, via their effects on the soil microbial community, can influence plant-soil feedbacks. 2.We first examined the effects of above-ground (AG) and below-ground (B) insect herbivory on the composition of pyrrolizidine alkaloids (PAs) in roots and on soil fungi in roots and rhizosphere soil of ragwort (Jacobaea vulgaris). The composition of fungal communities in roots and rhizosphere soil was affected by both AG and BG herbivory, but fungal composition also differed considerably between roots and rhizosphere soil. The composition of PAs in roots was affected only by BG herbivory. 3.Thirteen different fungal species were detected in roots and rhizosphere soil. The presence of the potentially pathogenic fungus Fusarium oxysporum decreased and that of Phoma exigua increased in presence of BG herbivory, but only in soil samples. 4.We then grew new plants in the soils conditioned by plants exposed to the herbivore treatments and in unconditioned soil. A subset of the new plants was exposed to foliar insect herbivory. Plant-soil feedback was strongly negative, but the feedback effect was least negative in soil conditioned by plants that had been exposed to BG herbivory. There was a negative direct effect of foliar herbivory on plant biomass during the feedback phase, but this effect was far less strong when the soil was conditioned by plants exposed to AG herbivory. AG herbivory during the conditioning phase also caused a soil feedback effect on the PA concentration in the foliage of ragwort. 5.Synthesis. Our results illustrate how insect herbivory can affect interactions between plants and soil organisms, and via these effects how herbivory can alter the performance of late-growing plants. Plant-soil feedback is emerging as an important theme in ecology and these results highlight that plant-soil feedback should be considered from a multitrophic AG and BG perspective
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can the negative plant soil feedback of Jacobaea vulgaris be explained by autotoxicity
Basic and Applied Ecology, 2012Co-Authors: Tess F J Van De Voorde, Wim H. Van Der Putten, Myriam Ruijten, Martijn T BezemerAbstract:Field and bioassay studies with Jacobaea vulgaris (ragwort) have shown that plants grow poorly in soil originating from the rhizosphere of this species and that this can influence the dynamics of ragwort populations during secondary succession. In the present study we examined whether the negative effect of ragwort on conspecifics may be due to autotoxicity. First, we experimentally established that ragwort exerts negative plant–soil feedback. We subsequently examined the inhibitory effects on germination and seedling performance of different strengths of aqueous extracts made from shoot and root tissues of ragwort, and from soil in which ragwort had been growing. The effects of the extracts were tested for seedlings growing in sterilised soil or in glass beads with water. Finally, the inhibitory effect of entire root fragments on seedling performance was tested. We observed that performance of seedlings growing in glass beads was significantly reduced by the high and medium strength root and shoot extracts. Extracts made from soil did not differ significantly from the control, and seedlings growing in sterilised soil were also not affected by ragwort extracts. Seed germination was significantly reduced by the high strength shoot extract only. The root length of seedlings growing in water with root fragments was reduced significantly. We conclude that under laboratory conditions ragwort can be autotoxic and discuss the role that autotoxicity may play in influencing the dynamics of ragwort populations during secondary succession.
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the importance of plant soil interactions soil nutrients and plant life history traits for the temporal dynamics of Jacobaea vulgaris in a chronosequence of old fields
Oikos, 2012Co-Authors: Tess F J Van De Voorde, Wim H. Van Der Putten, Martijn T BezemerAbstract:We examined to what extent temporal dynamics of Jacobaea vulgaris cover in old-fields were related to plant–soil feedback, soil nutrients, seed availability and performance, and seedling establishment. Long-term measurements at an experimental field and in ten old-fields representing a chronosequence following land abandonment revealed a remarkably similar hump-shaped temporal pattern of J. vulgaris cover, which peaked at about five years after abandonment. In a plant–soil feedback study, J. vulgaris biomass of plants grown in soil from all chronosequence fields was lower than in sterilized control soil. However, biomass of J. vulgaris in the feedback study was lower when grown in soil collected from fields with a high density of J. vulgaris plants than in soil from fields with a low density of J. vulgaris. When plants were grown again in the conditioned soil, a strong negative plant–soil feedback response was observed for soils from all fields. These results indicate that soils from all stages of the chronosequence can develop a strong negative soil feedback to J. vulgaris, and that there is a positive relationship between J. vulgaris density and the subsequent level of control by the soil community. In a common-garden experiment with turfs collected from the chronosequence fields in which J. vulgaris was seeded, seedling establishment was significantly lower in turfs from older than from young fields. In a seed bank study the number of emerging seedlings declined with time since abandonment of the field. In conclusion, negative plant–soil feedback is an important factor explaining the hump-shaped population development of J. vulgaris. However, it is not operating alone, as propagule availability and characteristics, and competition may also be important. Thus, in order to explain its contribution to plant population dynamics, the role of biotic plant–soil interactions, soil nutrients and life history characteristics along successional gradients should be considered from a community perspective.
