scholarly journals Environmental Nutrient Supply Directly Alters Plant Traits but Indirectly Determines Virus Growth Rate

2017 ◽  
Vol 8 ◽  
Author(s):  
Christelle Lacroix ◽  
Eric W. Seabloom ◽  
Elizabeth T. Borer
Keyword(s):  
Growth Rate ◽  
Plant Traits ◽  
Nutrient Supply ◽  
Virus Growth

Nutrient supply in browing cattle offered straw diets supplemented with barley or fishmeal

1986 ◽  
Vol 1986 ◽  
pp. 13-13
Author(s):  
I. Ortigues ◽  
T. Smith ◽  
J.D. Oldham ◽  
M.B. de Courtenay ◽  
J.W. Siviter
Keyword(s):  
Growth Rate ◽  
Nutrient Supply ◽  
Feeding Trials ◽  
Protein Rich

The effects of supplementing straw based diets with either a protein-rich (fishmeal) or a starch-rich (barley) concentrate or a combination of both were investigated using growing Friesian heifers. Digestion and feeding trials were run in parallel to determine the extent to which the growth rate responses to supplementation could be attributed to changes in nutrient supply.

scholarly journals Underwhelming the Immune Response: Effect of Slow Virus Growth on CD8+-T-Lymphocyte Responses

2004 ◽  
Vol 78 (5) ◽  
pp. 2247-2254 ◽  
Author(s):  
Gennady Bocharov ◽  
Burkhard Ludewig ◽  
Antonio Bertoletti ◽  
Paul Klenerman ◽  
Tobias Junt ◽  
...  
Keyword(s):  
Growth Rate ◽  
Viral Replication ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Immune Surveillance ◽  
Lymphocytic Choriomeningitis ◽  
Virus Infections ◽  
Lower Growth ◽  
Virus Growth ◽  
Ctl Responses

ABSTRACT The speed of virus replication has typically been seen as an advantage for a virus in overcoming the ability of the immune system to control its population growth. Under some circumstances, the converse may also be true: more slowly replicating viruses may evoke weaker cellular immune responses and therefore enhance their likelihood of persistence. Using the model of lymphocytic choriomeningitis virus (LCMV) infection in mice, we provide evidence that slowly replicating strains induce weaker cytotoxic-T-lymphocyte (CTL) responses than a more rapidly replicating strain. Conceptually, we show a “bell-shaped” relationship between the LCMV growth rate and the peak CTL response. Quantitative analysis of human hepatitis C virus infections suggests that a reduction in virus growth rate between patients during the incubation period is associated with a spectrum of disease outcomes, from fulminant hepatitis at the highest rate of viral replication through acute resolving to chronic persistence at the lowest rate. A mathematical model for virus-CTL population dynamics (analogous to predator [CTL]-prey [virus] interactions) is applied in the clinical data-driven analysis of acute hepatitis B virus infection. The speed of viral replication, through its stimulus of host CTL responses, represents an important factor influencing the pathogenesis and duration of virus persistence within the human host. Viruses with lower growth rates may persist in the host because they “sneak through” immune surveillance.

scholarly journals Adaptation of Biotrophic Leaf Pathogens to Fertilization-Mediated Changes in Plant Traits: A Comparison of the Optimization Principle to Invasion Fitness

2020 ◽  
Vol 110 (5) ◽  
pp. 1039-1048
Author(s):  
Pierre-Antoine Précigout ◽  
Corinne Robert ◽  
David Claessen
Keyword(s):  
Growth Rate ◽  
Latent Period ◽  
Exponential Growth ◽  
Plant Traits ◽  
Adaptive Dynamics ◽  
Spore Production ◽  
Exponential Growth Rate ◽  
Evolutionarily Stable Strategies ◽  
Invasion Fitness ◽  
Evolutionary Response

One of the conclusions of evolutionary ecology applied to agroecosystem management is that sustainable disease management strategies must be adaptive to overcome the immense adaptive potential of crop pathogens. In this context, knowledge of how pathogens adapt to changes in cultural practices is necessary. In this article we address the issue of the evolutionary response of biotrophic crop pathogens to changes in fertilization practices. For this purpose, we compare predictions of latent period evolution based on three empirical fitness measures (seasonal spore production, within-season exponential growth rate, and area under disease progress curves [AUDPCs]) with predictions based on the concept of invasion fitness from adaptive dynamics. We use pairwise invisibility plots to identify the evolutionarily stable strategies (ESSs) of the pathogen latent period. We find that the ESS latent period is in between the latent periods that maximize the seasonal spore production and the within-season exponential growth rate of the pathogen. The latent periods that maximize the AUDPC are similar to those of the ESS latent periods. The AUDPC may therefore be a critical variable to determine the issue of between-strain competition and shape pathogen evolution.

scholarly journals Genotype-specific relationships among phosphorus use, growth and abundance in Daphnia pulicaria

2017 ◽  
Vol 4 (12) ◽  
pp. 170770 ◽  
Author(s):  
Ryan E. Sherman ◽  
Priyanka Roy Chowdhury ◽  
Kristina D. Baker ◽  
Lawrence J. Weider ◽  
Punidan D. Jeyasingh
Keyword(s):  
Growth Rate ◽  
Ecological Stoichiometry ◽  
Competitive Ability ◽  
Nutrient Content ◽  
Nutrient Supply ◽  
P Limitation ◽  
Poor Predictor ◽  
Nutrient Use ◽  
P Content ◽  
Stoichiometric Models

The framework ecological stoichiometry uses elemental composition of species to make predictions about growth and competitive ability in defined elemental supply conditions. Although intraspecific differences in stoichiometry have been observed, we have yet to understand the mechanisms generating and maintaining such variation. We used variation in phosphorus (P) content within a Daphnia species to test the extent to which %P can explain variation in growth and competition. Further, we measured 33 P kinetics (acquisition, assimilation, incorporation and retention) to understand the extent to which such variables improved predictions. Genotypes showed significant variation in P content, 33 P kinetics and growth rate. P content alone was a poor predictor of growth rate and competitive ability. While most genotypes exhibited the typical growth penalty under P limitation, a few varied little in growth between P diets. These observations indicate that some genotypes can maintain growth under P-limited conditions by altering P use, suggesting that decomposing P content of an individual into physiological components of P kinetics will improve stoichiometric models. More generally, attention to the interplay between nutrient content and nutrient-use is required to make inferences regarding the success of genotypes in defined conditions of nutrient supply.

scholarly journals Graminoids vary in functional traits, carbon dioxide and methane fluxes in a restored peatland: implications for modeling carbon storage

2021 ◽  
Author(s):  
Ellie M Goud ◽  
Sabrina Touchette ◽  
Ian B Strachan ◽  
Maria Strack
Keyword(s):  
Growth Rate ◽  
Functional Groups ◽  
Carbon Storage ◽  
Plant Traits ◽  
Carbon Sink ◽  
Functional Variation ◽  
Considerable Uncertainty ◽  
Leaf Physiology ◽  
Gas Fluxes ◽  
Continuous Plant

One metric of peatland restoration success is the re-establishment of a carbon sink, yet considerable uncertainty remains around the timescale of carbon sink trajectories. Conditions post-restoration may promote the establishment of vascular plants such as graminoids, often at greater density than would be found in undisturbed peatlands, with consequences for carbon storage. Although graminoid species are often considered as a single plant functional type (PFT) in land-atmosphere models, our understanding of functional variation among graminoid species is limited, particularly in a restoration context. We used a traits-based approach to evaluate graminoid functional variation and to assess whether different graminoid species should be considered a single PFT or multiple types. We tested hypotheses that greenhouse gas fluxes (CO2, CH4) would vary due to differences in plant traits among five graminoid species in a restored peatland in central Alberta, Canada. We further hypothesized that species would form two functionally distinct groupings based on taxonomy (grass, sedge). Differences in gas fluxes among species were primarily driven by variation in leaf physiology related to photosynthetic efficiency and resource-use, and secondarily by plant size. Multivariate analyses did not reveal distinct functional groupings based on taxonomy or environmental preferences. Rather, we identified functional groups defined by continuous plant traits and carbon fluxes that are consistent with ecological strategies related to differences in growth rate, resource-acquisition, and leaf economics. These functional groups displayed larger carbon storage potential than currently-applied graminoid PFTs. Existing PFT designations in peatland models may be more appropriate for pristine or high-latitude systems than those under restoration. Although replacing PFTs with continuous plant traits remains a challenge in peatlands, traits related to leaf physiology and growth rate strategies offer a promising avenue for future applications.

scholarly journals Changes in nutrient stoichiometry, elemental homeostasis and growth rate of aquatic litter-associated fungi in response to inorganic nutrient supply

2017 ◽  
Vol 11 (12) ◽  
pp. 2729-2739 ◽  
Author(s):  
Vladislav Gulis ◽  
Kevin A Kuehn ◽  
Louie N Schoettle ◽  
Desiree Leach ◽  
Jonathan P Benstead ◽  
...  
Keyword(s):  
Growth Rate ◽  
Nutrient Supply ◽  
Inorganic Nutrient ◽  
Nutrient Stoichiometry ◽  
Elemental Homeostasis

scholarly journals Root bacterial endophytes alter plant phenotype, but not physiology

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2606 ◽  
Author(s):  
Jeremiah A. Henning ◽  
David J. Weston ◽  
Dale A. Pelletier ◽  
Collin M. Timm ◽  
Sara S. Jawdy ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chlorophyll Content ◽  
Carbon Fixation ◽  
Plant Traits ◽  
Plant Biomass ◽  
Leaf Growth ◽  
Net Photosynthesis ◽  
Bacterial Strains ◽  
Plant Host ◽  
Plant Phenotype

Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from thePopulusroot microbiome, influenced plant phenotype. We chose three bacterial strains that differed in predicted metabolic capabilities, plant hormone production and metabolism, and secondary metabolite synthesis. We inoculated each bacterial strain on a single genotype ofPopulus trichocarpaand measured the response of plant growth related traits (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light–Asat, and saturating CO2–Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did not significantly increase plant carbon fixation and biomass, but their presence altered where and how carbon was being allocated in the plant host.

scholarly journals Using directed attenuation to enhance vaccine immunity

2020 ◽  
Author(s):  
Rustom Antia ◽  
Hasan Ahmed ◽  
James J Bull
Keyword(s):  
Growth Rate ◽  
Genetic Engineering ◽  
Immune Evasion ◽  
Viral Infections ◽  
Wild Type Virus ◽  
Wild Type ◽  
Virus Growth ◽  
Viral Growth ◽  
Host Immune Responses ◽  
Effective Interventions

AbstractMany viral infections can be prevented by immunizing with live, attenuated vaccines. Early methods of attenuation were hit-and-miss, and these are now much improved by genetic engineering. But even current attenuation methods operate on the principle of genetic harm, reducing the virus’s ability to grow, which in turn limits the host immune response below that of infection by wild-type. We use mathematical models of the dynamics of virus and its control by innate and adaptive immunity to explore the tradeoff between attenuation of virus growth and the generation of immunity. Our analysis suggests that directed attenuation that disables key viral defenses against the host immune responses may attenuate viral growth without compromising, and potentially even enhancing the generation of immunity. We explore which immune evasion pathways should be attenuated and how attenuating multiple pathways could lead to robust attenuation of pathology with enhancement of immunity.Author summaryLive attenuated virus vaccines are among the most effective interventions to combat viral infections. Historically, the mechanism of attenuation has been one of genetically reduced viral growth rate, often achieved by adapting the virus to grow in a novel cells. More recent attenuation methods use genetic engineering but also are thought to impair viral growth rate. These classical attenuations typically result in a tradeoff whereby attenuation depresses the within-host viral load and pathology (which is beneficial to vaccine design), but reduces immunity (which is not beneficial). We use models to explore ways of directing the attenuation of a virus to avoid this tradeoff. We show that directed attenuation by interfering with (some) viral immune-evasion pathways can yield a mild infection but elicit higher levels of immunity than of the wild-type virus.

Mutations close to functional motif IV in HSV-1 UL5 helicase that confer resistance to HSV helicase–primase inhibitors, variously affect virus growth rate and pathogenicity

2008 ◽  
Vol 80 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Subhajit Biswas ◽  
Laurence S. Tiley ◽  
Holger Zimmermann ◽  
Alexander Birkmann ◽  
Hugh J. Field
Keyword(s):  
Growth Rate ◽  
Functional Motif ◽  
Virus Growth ◽  
Hsv 1
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