Dataset Information

Differential resistance among host and non-host species underlies the variable success of the hemi-parasitic plant Rhinanthus minor.

ABSTRACT:

Background and aims

Rhinanthus minor is a root hemiparasitic plant that attacks a wide range of host species which are severely damaged by the parasite. Rhinanthus minor also attempts unsuccessfully to form connections to a range of non-hosts which in contrast are not damaged by the parasite; however, the underlying physiological basis of these differences is not fully understood.

Methods

Biomass of host-parasite combinations was studied, and histology, electron microscopy and FT-IR microspectroscopy were used to determine the cellular-level interactions between Rhinanthus haustoria (the parasite's connective structure) and the roots of a range of potential host species.

Results

Two distinct defence responses were observed in the non-host forbs Plantago lanceolata and Leucanthemum vulgare. Firstly, L. vulgare was able to encapsulate the parasite's invading structures preventing it from gaining access to the stele. This was supported by FT-IR microspectroscopy, used to monitor lignification in response to Rhinanthus haustoria. Secondly, host cell fragmentation was observed at the interface between the parasite and P. lanceolata. Growth data confirmed the non-host status of the two forbs whilst, in contrast, grasses and a legume which were good hosts showed no evidence of defence at the host/parasite interface.

Conclusions

Variable resistance to Rhinanthus is shown for the first time to be controlled by cellular-level resistance to haustoria by either cell fragmentation or lignification at the host/parasite interface.

SUBMITTER: Cameron DD

PROVIDER: S-EPMC2803582 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Differential resistance among host and non-host species underlies the variable success of the hemi-parasitic plant Rhinanthus minor.

Cameron Duncan D DD Coats Alison M AM Seel Wendy E WE

Annals of botany 20060928 6

<h4>Background and aims</h4>Rhinanthus minor is a root hemiparasitic plant that attacks a wide range of host species which are severely damaged by the parasite. Rhinanthus minor also attempts unsuccessfully to form connections to a range of non-hosts which in contrast are not damaged by the parasite; however, the underlying physiological basis of these differences is not fully understood.<h4>Methods</h4>Biomass of host-parasite combinations was studied, and histology, electron microscopy and FT- ...[more]

PMID: 17008350

Similar Datasets

Project description:Phelipanche ramosa (L.) Pomel (branched broomrape) is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host's expense so that host-parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L.) (oilseed rape) and two weed species, Capsella bursa-pastoris (L.) Medik. and Geranium dissectum (L.). Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34 to 84%). B. napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per host plant, regardless of host growth rate. Results will be incorporated into a mechanistic model in order to analyze the effect of parasitic plant species on weed community assembly and to design new cropping systems for controlling P. ramosa.

Project description:Background and aims:Assessing the resilience of plant-animal interactions is critical to understanding how plant communities respond to habitat disturbances. Most ecosystems experience some level of natural disturbance (e.g. wildfires) to which many organisms are adapted. Wildfires have structured biotic communities for millennia; however, the effects of fire on interactions such as pollination have only recently received attention. A few studies have shown that generalist plants can buffer the impact of fires by pollinator replacement, suggesting that the resilience to disturbance could depend on the level of specialization of the interactions. Here, we hypothesize that (1) fires could impose negative effects on plants with specialized pollination systems, and (2) in large wildfires, these negative effects will be stronger with increasing distance inside the burnt area because pollinators will need more time to recolonize. Methods:These questions were tested in the specialized pollination system of a widespread Mediterranean palm, Chamaerops humilis. The post-fire pollination resilience was assessed in replicated wildfires representing three post-fire ages by measuring the abundance of beetle pollinators and by estimating fruit set (i.e. the proportion of flowers setting fruits) in burnt and unburnt areas. To test for distance effects, plants were sampled along transects inside the burnt area. Key Results:Despite a marked post-fire decline in the specialist pollinator, exacerbated by the distance from the fire's edge, the palm's fruit set was barely affected. The temporary replacement by a sap beetle at burnt sites - an effective pollinator that had not been previously recognized - provided post-fire reproductive resilience. Conclusions:Differential pollinator responses to disturbance can ensure plant success even in plants with only two functionally similar pollinators. This highlights the importance of pollinator replacement and dynamics for the resilience of interactions and ultimately of plant reproduction in disturbance-prone ecosystems.

Project description:BackgroundTo understand the ecological and evolutionary consequences of species interactions in food webs necessitates that interactions are properly identified. Genetic analyses suggest that many supposedly generalist parasitoid species should rather be defined as multiple species with a more narrow diet, reducing the probability that such species may mediate indirect interactions such as apparent competition among hosts. Recent studies showed that the parasitoid Asecodes lucens mediate apparent competition between two hosts, Galerucella tenella and G. calmariensis, affecting both interaction strengths and evolutionary feedbacks. The same parasitoid was also recorded from other species in the genus Galerucella, suggesting that similar indirect effects may also occur for other species pairs.MethodsTo explore the possibility of such interactions, we sequenced mitochondrial and nuclear genetic markers to resolve the phylogeny of both host and parasitoid and to test the number of parasitoid species involved. We thus collected 139 Galerucella larvae from 8 host plant species and sequenced 31 adult beetle and 108 parasitoid individuals.ResultsThe analysis of the Galerucella data, that also included sequences from previous studies, verified the five species previously documented as reciprocally monophyletic, but the Bayesian species delimitation for A. lucens suggested 3-4 cryptic taxa with a more specialised host use than previously suggested. The gene data analyzed under the multispecies coalescent model allowed us to reconstruct the species tree phylogeny for both host and parasitoid and we found a fully congruent coevolutionary pattern suggesting that parasitoid speciation followed upon host speciation.ConclusionUsing multilocus sequence data in a Bayesian species delimitation analysis we propose that hymenopteran parasitoids of the genus Asecodes that infest Galerucella larvae constitute at least three species with narrow diet breath. The evolution of parasitoid Asecodes and host Galerucella show a fully congruent coevolutionary pattern. This finding strengthens the hypothesis that the parasitoid in host search uses cues of the host rather than more general cues of both host and plant.

Dataset Information

Differential resistance among host and non-host species underlies the variable success of the hemi-parasitic plant Rhinanthus minor.

Background and aims

Methods

Results

Conclusions

Publications

Differential resistance among host and non-host species underlies the variable success of the hemi-parasitic plant Rhinanthus minor.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets