scholarly journals Genotype-specific benefits and risks of a mutualist association during natural epidemics

2021 ◽  
Author(s):  
Jenalle L. Eck ◽  
Minna-Maarit Kytöviita ◽  
Anna-Liisa Laine
Keyword(s):  
Mycorrhizal Fungi ◽  
Disease Risk ◽  
Plantago Lanceolata ◽  
Host Susceptibility ◽  
Ecological Communities ◽  
Protective Effects ◽  
Host Genotype ◽  
Susceptible Host ◽  
Wild Host ◽  
Mycorrhizal Association

While both plant-associated pathogenic and mutualistic microbes are ubiquitous across ecosystems, how they interact to determine disease risk in natural, genetically diverse populations is not known. To test whether mycorrhizal fungi provide protection against infection, and whether this functions in a genotype-specific manner, we conducted a field experiment in three naturally-occurring epidemics of a fungal pathogen, Podosphaera plantaginis, infecting a host plant, Plantago lanceolata, in the Åland Islands, Finland. In each population, we collected field epidemiological data on mycorrhizal-inoculated and non-mycorrhizal experimental plants originating from six allopatric populations. Mycorrhizal association caused host genotype-specific changes in growth and infection rates in the host populations, but reduced infection severity in hosts from every genetic origin. Protection occurred via changes in the relationship between growth and infection in the host individuals: mycorrhizal individuals grew larger without increasing their infection risk or load. More susceptible host genotypes received stronger protective effects from mycorrhizae. Our results show that mycorrhizal fungi produce host genotype-specific growth and defensive benefits and alter infection risks in wild host populations. Understanding how mutualism-derived protection alters host susceptibility to disease will be important for predicting infection outcomes in ecological communities and in agriculture.

Tree species rather than type of mycorrhizal association drives inorganic and organic nitrogen acquisition in tree-tree interactions

2021 ◽  
Author(s):  
Robert Reuter ◽  
Olga Ferlian ◽  
Mika Tarkka ◽  
Nico Eisenhauer ◽  
Karin Pritsch ◽  
...  
Keyword(s):  
Tree Species ◽  
Mycorrhizal Fungi ◽  
Prunus Avium ◽  
N Uptake ◽  
Organic N ◽  
Acer Pseudoplatanus ◽  
N Sources ◽  
Mycorrhizal Association ◽  
N Acquisition ◽  
Inorganic And Organic

Abstract Mycorrhizal fungi play an important role for the nitrogen (N) supply of trees. The influence of different mycorrhizal types on N acquisition in tree-tree interactions is, however, not well understood, particularly with regard to the competition for growth-limiting N. We studied the effect of competition between temperate forest tree species on their inorganic and organic N acquisition in relation to their mycorrhizal type (i.e., arbuscular mycorrhiza or ectomycorrhiza). In a field experiment, we quantified net N uptake capacity from inorganic and organic N sources using 15N/13C stable isotopes for arbuscular mycorrhizal tree species (i.e., Acer pseudoplatanus L., Fraxinus excelsior L., and Prunus avium L.) as well as ectomycorrhizal tree species (i.e., Carpinus betulus L., Fagus sylvatica L., and Tilia platyphyllos Scop.). All species were grown in intra- and interspecific competition (i.e., monoculture or mixture). Our results showed that N sources were not used complementarily depending on a species´ mycorrhizal association, but their uptake rather depended on the competitor indicating species-specific effects. Generally, ammonium was preferred over glutamine and glutamine over nitrate. In conclusion, our findings suggest that inorganic and organic N acquisition of the studied temperate tree species is less regulated by mycorrhizal association, but rather by the availability of specific N sources in the soil as well as the competitive environment of different tree species.

Warming effects on biomass allocation are jointly regulated by precipitation and mycorrhizal association in terrestrial plants

2021 ◽  
Author(s):  
Xuhui Zhou ◽  
Lingyan Zhou ◽  
Yanghui He ◽  
Yuling Fu ◽  
Zhenggang Du ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Mycorrhizal Fungi ◽  
Global Scale ◽  
Mean Annual Precipitation ◽  
Shoot Biomass ◽  
Terrestrial Plants ◽  
Terrestrial Carbon ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Mycorrhizal Association

Abstract Biomass allocation in plants is fundamental for understanding and predicting terrestrial carbon storage. Recent studies suggest that climate warming can differentially affect root and shoot biomass, and subsequently alter root: shoot ratio. However, warming effects on root: shoot ratio and their underlying drivers at a global scale remain unclear. Using a global synthesis of >300 studies, we here show that warming significantly increases biomass allocation to roots (by 13.1%), and two factors drive this response: mean annual precipitation of the site, and the type of mycorrhizal fungi associated with a plant. Warming-induced allocation to roots is greater in relatively drier habitats compared to shoots (by 15.1%), but lower in wetter sites (by 4.9%), especially for plants associated with arbuscular mycorrhizal fungi compared to ectomycorrhizal fungi. Root-biomass responses to warming predominantly determine the biomass allocation in terrestrial plants suggesting that warming can reinforce the importance of belowground resource uptake. Our study highlights that the wetness or dryness of a site and plants’ mycorrhizal associations strongly regulate terrestrial carbon cycle by altering biomass allocation strategies in a warmer world.

scholarly journals Science and Healthy Meals in the World: Nutritional Epigenomics and Nutrigenetics of the Mediterranean Diet

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1748 ◽  
Author(s):  
Fabio Caradonna ◽  
Ornella Consiglio ◽  
Claudio Luparello ◽  
Carla Gentile
Keyword(s):  
Mediterranean Diet ◽  
Disease Risk ◽  
Cooking Methods ◽  
Intangible Cultural Heritage ◽  
Protective Effects ◽  
Positive Health ◽  
Food Components ◽  
The Mediterranean ◽  
The Impact ◽  
Scientific Topic

The Mediterranean Diet (MD), UNESCO Intangible Cultural Heritage of Humanity, has become a scientific topic of high interest due to its health benefits. The aim of this review is to pick up selected studies that report nutrigenomic or nutrigenetic data and recapitulate some of the biochemical/genomic/genetic aspects involved in the positive health effects of the MD. These include (i) the antioxidative potential of its constituents with protective effects against several diseases; (ii) the epigenetic and epigenomic effects exerted by food components, such as Indacaxanthin, Sulforaphane, and 3-Hydroxytyrosol among others, and their involvement in the modulation of miRNA expression; (iii) the existence of predisposing or protective human genotypes due to allelic diversities and the impact of the MD on disease risk. A part of the review is dedicated to the nutrigenomic effects of the main cooking methods used in the MD and also to a comparative analysis of the nutrigenomic properties of the MD and other diet regimens and non-MD-related aliments. Taking all the data into account, the traditional MD emerges as a diet with a high antioxidant and nutrigenomic modulation power, which is an example of the “Environment-Livings-Environment” relationship and an excellent patchwork of interconnected biological actions working toward human health.

scholarly journals Bacteria Associated with Spores of the Arbuscular Mycorrhizal Fungi Glomus geosporum and Glomus constrictum

2005 ◽  
Vol 71 (11) ◽  
pp. 6673-6679 ◽  
Author(s):  
David Roesti ◽  
Kurt Ineichen ◽  
Olivier Braissant ◽  
Dirk Redecker ◽  
Andres Wiemken ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Plantago Lanceolata ◽  
Arbuscular Mycorrhizal ◽  
Spore Wall ◽  
Wall Layer ◽  
Single Spore ◽  
Bacterial Populations ◽  
Glomus Geosporum

ABSTRACT Spores of the arbuscular mycorrhizal fungi (AMF) Glomus geosporum and Glomus constrictum were harvested from single-spore-derived pot cultures with either Plantago lanceolata or Hieracium pilosella as host plants. PCR-denaturing gradient gel electrophoresis analysis revealed that the bacterial communities associated with the spores depended more on AMF than host plant identity. The composition of the bacterial populations linked to the spores could be predominantly influenced by a specific spore wall composition or AMF exudate rather than by specific root exudates. The majority of the bacterial sequences that were common to both G. geosporum and G. constrictum spores were affiliated with taxonomic groups known to degrade biopolymers (Cellvibrio, Chondromyces, Flexibacter, Lysobacter, and Pseudomonas). Scanning electron microscopy of G. geosporum spores revealed that these bacteria are possibly feeding on the outer hyaline spore layer. The process of maturation and eventual germination of AMF spores might then benefit from the activity of the surface microorganisms degrading the outer hyaline wall layer.

scholarly journals Sporadic Creutzfeldt-Jakob Disease: Prion Pathology in Medulla Oblongata—Possible Routes of Infection and Host Susceptibility

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Diego Iacono ◽  
Sergio Ferrari ◽  
Matteo Gelati ◽  
Gianluigi Zanusso ◽  
Sara Mariotto ◽  
...  
Keyword(s):  
Prion Protein ◽  
Environmental Exposure ◽  
Phenotypic Variability ◽  
Host Susceptibility ◽  
Motor Nucleus ◽  
Host Genotype ◽  
Dorsal Motor Nucleus ◽  
Jakob Disease ◽  
Medullary Nuclei ◽  
Codon 129

Sporadic Creutzfeldt-Jakob disease (sCJD), the most frequent human prion disorder, is characterized by remarkable phenotypic variability, which is influenced by the conformation of the pathologic prion protein and the methionine/valine polymorphic codon 129 of the prion protein gene. While the etiology of sCJD remains unknown, it has been hypothesized that environmental exposure to prions might occur through conjunctival/mucosal contact, oral ingestion, inhalation, or simultaneous involvement of the olfactory and enteric systems. We studied 21 subjects with definite sCJD to assess neuropathological involvement of the dorsal motor nucleus of the vagus and other medullary nuclei and to evaluate possible associations with codon 129 genotype and prion protein conformation. The present data show that prion protein deposition was detected in medullary nuclei of distinct sCJD subtypes, either valine homozygous or heterozygous at codon 129. These findings suggest that an “environmental exposure” might occur, supporting the hypothesis that external sources of contamination could contribute to sCJD in susceptible hosts. Furthermore, these novel data could shed the light on possible causes of sCJD through a “triple match” hypothesis that identify environmental exposure, host genotype, and direct exposure of specific anatomical regions as possible pathogenetic factors.

Natural stressors and disease risk: does the threat of predation increase amphibian susceptibility to ranavirus?

2012 ◽  
Vol 90 (7) ◽  
pp. 893-902 ◽  
Author(s):  
N.A. Haislip ◽  
J.T. Hoverman ◽  
D.L. Miller ◽  
M.J. Gray
Keyword(s):  
Predation Risk ◽  
Stress Responses ◽  
Species Interactions ◽  
Disease Risk ◽  
Natural Populations ◽  
Emerging Infectious Diseases ◽  
Host Susceptibility ◽  
Continuous Exposure ◽  
Amphibian Species ◽  
Predator Cues

Emerging infectious diseases have been identified as threats to biodiversity, yet our understanding of the factors contributing to host susceptibility to pathogens within natural populations remains limited. It has been proposed that species interactions within communities affect host susceptibility to pathogens, thereby contributing to disease emergence. In particular, predation risk is a common natural stressor that has been hypothesized to compromise immune function of prey through chronic stress responses possibly leading to increased susceptibility to pathogens. We examined whether predation risk experienced during the development of four larval anuran species increases susceptibility (mortality and infection) to ranaviruses, a group of viruses responsible for amphibian die-offs. Using controlled laboratory experiments, we exposed each species to a factorial combination of two virus treatments (no virus or virus) crossed with three predator-cue treatments (no predators, larval dragonflies, or adult water bugs). All four amphibian species reduced activity by 22%–48% following continuous exposure to predator cues. In addition, virus exposure significantly reduced survival by 17%–100% across all species. However, exposure to predator cues did not interact with the virus treatments to elevate mortality or viral load. Our results suggest that the expression of predator-induced plasticity in anuran larvae does not increase ranaviral disease risk.

scholarly journals Symbiotic association between golden berry (Physalis peruviana) and arbuscular mycorrhizal fungi in heavy metal-contaminated soil

2017 ◽  
Vol 57 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Marieta Hristozkova ◽  
Maria Geneva ◽  
Ira Stancheva ◽  
Ivan Iliev ◽  
Concepción Azcón-Aguilar
Keyword(s):  
Fatty Acids ◽  
Heavy Metal ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Protein Accumulation ◽  
Symbiotic Association ◽  
Tropical Fruit ◽  
Physalis Peruviana ◽  
Mycorrhizal Association

AbstractPhysalis peruvianais one of the most promising tropical fruit plants because of its rapid growth, high yield, and nutritional quality. This study was designed to investigate plant development under heavy metal contamination (Cd, Pb) and responsiveness to arbuscular mycorrhizal fungi (AMF) colonization byRhizophagus clarumandClaroideoglomus claroideum. The antioxidant capacity, total lipid content and fatty acid profile in fruits, accumulation of Cd and Pb in different plant parts, plant dry biomass, and mycorrhizal colonization were determined. As a result of inoculation, a considerable reduction in Cd and Pb in the fruits was observed, compared with non-inoculated plants. The fruit number and dry weight increased in plants associated withC. claroideum.These plants also showed higher acid phosphatase activity, root protein accumulation and glomalin production. The type of antioxidant defense was AMF strain-dependent. Antioxidant activity and H2O2neutralization were enzymatic rather than non-enzymatic processes in the fruits ofC. claroideumplants compared with those forming an association withR. clarum. Mycorrhizal establishment changed the composition and concentration of fruits’ fatty acids. The ratio of unsaturated fatty acids was increased. With respect to the accumulation of bioactive compounds in golden berry the present findings are important for obtaining the optimum benefits of mycorrhizal association under unfavorable conditions.

scholarly journals Temperature effects on parasite prevalence in a natural hybrid complex

2010 ◽  
Vol 7 (1) ◽  
pp. 108-111 ◽  
Author(s):  
Corine N. Schoebel ◽  
Christoph Tellenbach ◽  
Piet Spaak ◽  
Justyna Wolinska
Keyword(s):  
Protozoan Parasite ◽  
Parasite Prevalence ◽  
Host Susceptibility ◽  
Host Genotype ◽  
Genotype By Environment ◽  
Hybrid Complex ◽  
Influence Of Temperature On ◽  
Temperature Interaction ◽  
Host Parasite ◽  
Genetic Specificity

Both host susceptibility and parasite infectivity commonly have a genetic basis, and can therefore be shaped by coevolution. However, these traits are often sensitive to environmental variation, resulting in genotype-by-environment interactions. We tested the influence of temperature on host–parasite genetic specificity in the Daphnia longispina hybrid complex, exposed to the protozoan parasite Caullerya mesnili . Infection rates were higher at low temperature. Furthermore, significant differences between host clones, but not between host taxa, and a host genotype-by-temperature interaction were observed.

Plant carbon limitation does not reduce nitrogen transfer from arbuscular mycorrhizal fungi to Plantago lanceolata

2015 ◽  
Vol 396 (1-2) ◽  
pp. 369-380 ◽  
Author(s):  
Haiyang Zhang ◽  
Waldemar Ziegler ◽  
Xingguo Han ◽  
Susan Trumbore ◽  
Henrik Hartmann
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Plantago Lanceolata ◽  
Arbuscular Mycorrhizal ◽  
Nitrogen Transfer ◽  
Carbon Limitation

scholarly journals Competitors as accomplices: seaweed competitors hide corals from predatory sea stars

2015 ◽  
Vol 282 (1814) ◽  
pp. 20150714 ◽  
Author(s):  
Cody S. Clements ◽  
Mark E. Hay
Keyword(s):  
Field Experiments ◽  
Coral Cover ◽  
Ecological Communities ◽  
Protective Effects ◽  
Sea Star ◽  
Sea Stars ◽  
Macroalgal Blooms ◽  
Feeding Experiments ◽  
High Preference ◽  
And Function

Indirect biotic effects arising from multispecies interactions can alter the structure and function of ecological communities—often in surprising ways that can vary in direction and magnitude. On Pacific coral reefs, predation by the crown-of-thorns sea star, Acanthaster planci , is associated with broad-scale losses of coral cover and increases of macroalgal cover. Macroalgal blooms increase coral–macroalgal competition and can generate further coral decline. However, using a combination of manipulative field experiments and observations, we demonstrate that macroalgae, such as Sargassum polycystum , produce associational refuges for corals and dramatically reduce their consumption by Acanthaster . Thus, as Acanthaster densities increase, macroalgae can become coral mutualists, despite being competitors that significantly suppress coral growth. Field feeding experiments revealed that the protective effects of macroalgae were strong enough to cause Acanthaster to consume low-preference corals instead of high-preference corals surrounded by macroalgae. This highlights the context-dependent nature of coral–algal interactions when consumers are common. Macroalgal creation of associational refuges from Acanthaster predation may have important implications for the structure, function and resilience of reef communities subject to an increasing number of biotic disturbances.

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