Parasite–host interactions in Castilleja and Orthocarpus

1997 ◽  
Vol 75 (8) ◽  
pp. 1252-1260 ◽  
Author(s):  
Diethart Matthies
Keyword(s):  
Biomass Allocation ◽  
Host Plants ◽  
Parasitic Plant ◽  
Negative Effects ◽  
Host Interactions ◽  
Castilleja Integra ◽  
Host Growth ◽  
Total Productivity ◽  
Medicago Sativa L ◽  
Shoot Mass

Growth, reproduction, and biomass allocation were studied in three perennial root hemiparasites, Castilleja integra Gray, Castilleja miniata Dougl., Castilleja chromosa A. Nels., and the annual hemiparasite Orthocarpus purpurascens Benth. grown either without or with a host plant. In addition, the effects of the hemiparasites on the host plants were investigated. All four hemiparasites could grow without a host, indicating that they are facultative parasites; O. purpurascens and C. chromosa produced flowers without a host. However, shoot mass of parasites with a host was 3–41 times that of parasites without a host. For C. miniata, C. chromosa, and O. purpurascens the growth of parasites grown with the legume Medicago sativa L. was compared with that of parasites grown with the grass Lolium perenne L. The legume was consistently a more beneficial host than the grass. In C. miniata and C. chromosa, patterns of biomass allocation were also influenced by the host type. The proportion of biomass allocated to roots was lower in parasites grown with the legume than in plants without a host, whereas it was higher in parasites grown with the grass. The parasites had strong negative effects on host growth, but the extent of host damage depended on the particular parasite–host combination. Castilleja chromosa and O. purpurascens affected the growth of the legume more strongly than that of the grass, whereas C. miniata affected the grass more strongly than the legume. Grasses parasitized by C. miniata allocated more biomass to roots than unparasitized grasses. In the other parasite–host associations the pattern of biomass allocation of the host was not influenced by parasitization. Because the biomass produced by the four hemiparasites was lower than the reduction in host biomass caused by parasitism, the parasites reduced total productivity. Therefore, the studied hemiparasites may potentially affect the structure and diversity of their communities. Key words: biomass allocation, host damage, parasite benefit, parasitic plant.

Effects of Submergence and Nitrogen Concentration on the Resources Utilization of Alternanthera philoxeroides

2013 ◽  
Vol 864-867 ◽  
pp. 239-242
Author(s):  
Wen Juan Ding ◽  
Hua Yong Zhang ◽  
Fang Juan Zhang
Keyword(s):  
Water Level ◽  
Biomass Allocation ◽  
Invasive Plant ◽  
Nitrogen Concentration ◽  
Soluble Sugar ◽  
Nitrogen Pollution ◽  
Water Bodies ◽  
Alternanthera Philoxeroides ◽  
Negative Effects ◽  
Nitrogen Concentrations

This study examined the effects of submergence and nitrogen concentration on biomass allocation and nutrients utilization of an invasive plant Alternanthera philoxeroides. In the experiment, A. philoxeroides was applied to two water level treatments (0 and 25cm above the surface) across with two nitrogen concentrations (0 and 10 mg/l N). The results showed that submergence decreased leaf fraction and increased stem fraction, but high N changed this situation. In submergence, high N increased leaf fraction but decreased stem fraction due to leaves survival and maintenance. Submergence decreased root fraction and the content of soluble sugar in stem. The results suggested that high N concentration could counteract the negative effects of submergence. Therefore, the risk of A. philoxeroides invasion might be enhanced by nitrogen pollution in fluctuating water bodies, and should be attention intensely.

scholarly journals Nutraceutical Boom in Cancer: Inside the Labyrinth of Reactive Oxygen Species

2020 ◽  
Vol 21 (6) ◽  
pp. 1936 ◽  
Author(s):  
Maura Calvani ◽  
Amada Pasha ◽  
Claudio Favre
Keyword(s):  
Well Being ◽  
Epidemiological Studies ◽  
Long Term Results ◽  
Negative Effects ◽  
Cell Growth Arrest ◽  
Host Interactions ◽  
Health And Disease ◽  
Pros And Cons ◽  
The Individual

In recent years, epidemiological studies have shown that food is a very powerful means for maintaining a state of well-being and for health prevention. Many degenerative, autoimmune and neoplastic diseases are related to nutrition and the nutrient–organism interaction could define the balance between health and disease. Nutrients and dietary components influence epigenetic phenomena and modify drugs response; therefore, these food–host interactions can influence the individual predisposition to disease and its potential therapeutic response. Do nutraceuticals have positive or negative effects during chemotherapy? The use of nutraceutical supplements in cancer patients is a controversial debate without a definitive conclusion to date. During cancer treatment, patients take nutraceuticals to alleviate drug toxicity and improve long-term results. Some nutraceuticals may potentiate the effect of cytotoxic chemotherapy by inducing cell growth arrest, cell differentiation, and alteration of the redox state of cells, but in some cases, high levels of them may interfere with the effectiveness of chemotherapy, making cancer cells less reactive to chemotherapy. In this review, we highlighted the emerging opinions and data on the pros and cons on the use of nutraceutical supplements during chemotherapy.

Hemiparasite – host plant interactions and the impact of herbivory: a field experiment

Botany ◽  
2011 ◽  
Vol 89 (8) ◽  
pp. 537-544 ◽  
Author(s):  
Mickayla D. Van Hoveln ◽  
Bethany A. Evans ◽  
Victoria A. Borowicz
Keyword(s):  
Host Size ◽  
Schizachyrium Scoparium ◽  
Plant Interactions ◽  
Compensatory Response ◽  
Host Growth ◽  
Subsequent Flowering ◽  
Shoot Mass ◽  
The Impact ◽  
Early Late ◽  
Pedicularis Canadensis

Schizachyrium scoparium Michx. (Nash) growing naturally with varying numbers of the perennial hemiparasite Pedicularis canadensis L. were randomly assigned to one of four clipping treatments (none, early, late, early and late) to determine how parasitism and herbivory affect the grass and whether herbivory of the host indirectly affects hemiparasite growth. Any clipping eliminated subsequent flowering by S. scoparium in year 1 and reduced the number of plants that flowered in year 2, when no clipping occurred. Only hosts clipped early exhibited depressed growth after one summer. The following year plants that had been clipped twice the previous year produced the least shoot mass, and plants that were never clipped produced the most. Hemiparasite load was negatively associated with host shoot mass, especially in year 1, but did not alter the host’s compensatory response to clipping. The effects of host size and host clipping on the nearest hemiparasite were determined in year 1. Pedicularis canadensis shoot mass declined with host size if the host was clipped late, but increased with host size when clipping occurred once early in the season. Although the impact of hemiparasites and clipping on host growth are independent, clipping can alter the value of the host for parasites.

scholarly journals Molecular Parasitic Plant–Host Interactions

2016 ◽  
Vol 12 (12) ◽  
pp. e1005978 ◽  
Author(s):  
Simon B. Saucet ◽  
Ken Shirasu
Keyword(s):  
Parasitic Plant ◽  
Plant Host ◽  
Host Interactions

scholarly journals Glucosinolates from Host Plants Influence Growth of the Parasitic Plant Cuscuta gronovii and Its Susceptibility to Aphid Feeding

2016 ◽  
Vol 172 (1) ◽  
pp. 181-197 ◽  
Author(s):  
Jason D. Smith ◽  
Melkamu G. Woldemariam ◽  
Mark C. Mescher ◽  
Georg Jander ◽  
Consuelo M. De Moraes
Keyword(s):  
Host Plants ◽  
Parasitic Plant ◽  
Aphid Feeding ◽  
Cuscuta Gronovii

scholarly journals Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder

2006 ◽  
Vol 143 (2) ◽  
pp. 1037-1043 ◽  
Author(s):  
Jeannine K. Roney ◽  
Piyum A. Khatibi ◽  
James H. Westwood
Keyword(s):  
Host Plants ◽  
Parasitic Plant ◽  
Species Translocation

A technique for transplanting gall-making insects: impacts on gall-maker and parasitoid larvae

2008 ◽  
Vol 140 (5) ◽  
pp. 611-616
Author(s):  
Graham H. Cox ◽  
Stephen B. Heard ◽  
Julie M. Seehawer
Keyword(s):  
Drought Stress ◽  
Host Plants ◽  
Severe Drought ◽  
Solidago Altissima ◽  
Transplant Survival ◽  
Host Interactions ◽  
Transplant Stress ◽  
Individual Host ◽  
Thin Walled ◽  
One Year

AbstractPast studies of gall-maker-host interactions have been hampered by an inability to conduct experimental transplants of individuals between host plants. We describe a method for transplanting gall-maker larvae between galls on different individual host plants. Our method involves removing and inserting larvae through slits cut in young galls, and allows for healing and continuing growth of the gall. We developed and tested our method with larvae of the gall-making moth Gnorimoschema gallaesolidaginis Riley (Lepidoptera: Gelechiidae) on its two host plants, Solidago altissima L. and S. gigantea Ait. (Asteraceae). For three of four host × year combinations, unparasitized larvae survived at similar rates in transplants and controls. On one host in one year, transplant survival was low, possibly as a result of severe drought stress. Interestingly, survival of parasitized gall-maker larvae was lower in transplants for three of four host × year combinations, suggesting that gall-makers stressed by parasitoid attack are less able to tolerate transplant stress. Our technique may be applicable to many other gall-maker species, especially those making relatively thin-walled galls, and should represent a valuable new tool for the study of gall-maker-host interactions.

scholarly journals Why multiple infections favour virulent parasites

2018 ◽  
Author(s):  
Mircea T. Sofonea ◽  
Samuel Alizon ◽  
Yannis Michalakis
Keyword(s):  
Dynamical Systems ◽  
Selection Bias ◽  
Selective Pressure ◽  
Growth Traits ◽  
Natural Host ◽  
Multiple Infection ◽  
Multiple Infections ◽  
Host Interactions ◽  
Host Growth ◽  
Host Mortality

AbstractIt is now a fact that several strains/species (hereafter types) of parasites circulate in natural host populations. Parasite polymorphism can even occur within the same host, where distinct parasite types can interact in various ways. This can affect their transmission and, therefore, their evolution. We still lack general predictions regarding the evolution, in such multiple infection contexts, of virulence – the infection-induced host mortality, essentially because its emanation from within-host growth was often ignored so far. Here, we explicitly investigate within-host interactions, within-host competition outcomes, epidemiological dynamics and evolutionary invasibility using a formalism as general as possible. Focusing on chronic dimorphic infections caused by horizontally-transmitted microparasites, we apply both dynamical systems and probabilistic approaches to this bottom-up sequence of dynamics to explore the evolutionary outcomes. We show that within-host growth traits are under strong selective pressure and when small mutations affect them, most of the surviving mutants are more virulent than their resident. We thus identify a robust and unavoidable selection bias towards higher virulence.

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