Environmental Stress Determines The Colonization and Impact of An Endophytic Fungus On Invasive Knotweed

Abstract There is increasing evidence that microbes play a key role in some plant invasions. A diverse and widespread but little understood group of plant-associated microbes are the fungal root endophytes of the order Sebacinales. They are associated with exotic populations of invasive knotweed (Reynoutria ssp.) in Europe, but their effects on the invaders are unknown. We used the recently isolated Sebacinales root endophyte Serendipita herbamans to experimentally inoculate invasive knotweed and study root colonisation and effects on knotweed growth under different environmental conditions. We verified the inoculation success and fungal colonisation through immunofluorescence microscopy and qPCR. We found that S. herbamans strongly colonized invasive knotweed in low-nutrient and shade environments, but much less under drought or benign conditions. At low nutrients, the endophyte had a positive effect on plant growth, whereas the opposite was true under shaded conditions. Our study demonstrates that the root endophyte S. herbamans has the potential to colonize invasive knotweed fine roots and impact its growth, and it could thus also play a role in natural populations. Our results also show that effects of fungal endophytes on plants can be strongly environment-dependent, and may only be visible under stressful environmental conditions.

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Environmental stress determines the colonization and impact of an endophytic fungus on invasive knotweed

10.1101/2021.09.10.459653 ◽

2021 ◽

Author(s):

Sigisfredo Garnica ◽

Zhiyong Liao ◽

Samuel Hamard ◽

Frank Waller ◽

Madalin Parepa ◽

...

Keyword(s):

Environmental Conditions ◽

Immunofluorescence Microscopy ◽

Fungal Endophytes ◽

Natural Populations ◽

Plant Invasions ◽

List Type ◽

Root Colonisation ◽

Root Endophyte ◽

Fungal Root Endophytes ◽

Positive Effect

AbstractThere is increasing evidence that microbes play a key role in some plant invasions. A diverse and widespread but little understood group of plant-associated microbes are the fungal root endophytes of the order Sebacinales. They are associated with exotic populations of invasive knotweed (Reynoutria ssp.) in Europe, but their effects on the invaders are unknown.We used the recently isolated Sebacinales root endophyte Serendipita herbamans to experimentally inoculate invasive knotweed and study root colonisation and effects on knotweed growth under different environmental conditions. We verified the inoculation success and fungal colonisation through immunofluorescence microscopy and qPCR.We found that S. herbamans strongly colonized invasive knotweed in low-nutrient and shade environments, but much less under drought or benign conditions. At low nutrients, the endophyte had a positive effect on plant growth, whereas the opposite was true under shaded conditions.Synthesis. Our study demonstrates that the root endophyte S. herbamans has the potential to colonize invasive knotweed fine roots and impact its growth, and it could thus also play a role in natural populations. Our results also show that effects of fungal endophytes on plants can be strongly environment-dependent, and may only be visible under stressful environmental conditions.

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The sources of sex differences in aging in annual fishes

10.1101/2020.08.25.266411 ◽

2020 ◽

Author(s):

Martin Reichard ◽

Radim Blažek ◽

Jakub Žák ◽

Petr Kačer ◽

Oldřich Tomášek ◽

...

Keyword(s):

Sex Differences ◽

Social Environment ◽

Social Factors ◽

Environmental Conditions ◽

Natural Populations ◽

Experimental Results ◽

Survival Difference ◽

Captive Populations ◽

Baseline Mortality ◽

In The Wild

AbstractSex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and aging may be ameliorated by modulating social and environmental conditions.

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Springs ecosystems: vulnerable ecological islands where environmental conditions, life history traits, and human disturbance facilitate non-native plant invasions

Biological Invasions ◽

10.1007/s10530-019-02025-6 ◽

2019 ◽

Vol 21 (9) ◽

pp. 2963-2981 ◽

Cited By ~ 1

Author(s):

Kayleigh G. Nielson ◽

Karen M. Gill ◽

Abraham E. Springer ◽

Jeri D. Ledbetter ◽

Lawrence E. Stevens ◽

...

Keyword(s):

Life History ◽

Environmental Conditions ◽

Human Disturbance ◽

Life History Traits ◽

Plant Invasions ◽

Native Plant

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Simulated folivory increases vertical transmission of fungal endophytes that deter herbivores and alter tolerance to herbivory in Poa autumnalis

Annals of Botany ◽

10.1093/aob/mcaa021 ◽

2020 ◽

Vol 125 (6) ◽

pp. 981-991 ◽

Cited By ~ 2

Author(s):

Pedro E Gundel ◽

Prudence Sun ◽

Nikki D Charlton ◽

Carolyn A Young ◽

Tom E X Miller ◽

...

Keyword(s):

Vertical Transmission ◽

Transmission Rate ◽

Horizontal Transmission ◽

Fungal Endophytes ◽

Natural Populations ◽

Plant Tolerance ◽

Hyphal Density ◽

Symbiotic Fungi ◽

Symbiont Transmission ◽

Fitness Benefits

Abstract Background and Aims The processes that maintain variation in the prevalence of symbioses within host populations are not well understood. While the fitness benefits of symbiosis have clearly been shown to drive changes in symbiont prevalence, the rate of transmission has been less well studied. Many grasses host symbiotic fungi (Epichloë spp.), which can be transmitted vertically to seeds or horizontally via spores. These symbionts may protect plants against herbivores by producing alkaloids or by increasing tolerance to damage. Therefore, herbivory may be a key ecological factor that alters symbiont prevalence within host populations by affecting either symbiont benefits to host fitness or the symbiont transmission rate. Here, we addressed the following questions: Does symbiont presence modulate plant tolerance to herbivory? Does folivory increase symbiont vertical transmission to seeds or hyphal density in seedlings? Do plants with symbiont horizontal transmission have lower rates of vertical transmission than plants lacking horizontal transmission? Methods We studied the grass Poa autumnalis and its symbiotic fungi in the genus Epichloë. We measured plant fitness (survival, growth, reproduction) and symbiont transmission to seeds following simulated folivory in a 3-year common garden experiment and surveyed natural populations that varied in mode of symbiont transmission. Key Results Poa autumnalis hosted two Epichloë taxa, an undescribed vertically transmitted Epichloë sp. PauTG-1 and E. typhina subsp. poae with both vertical and horizontal transmission. Simulated folivory reduced plant survival, but endophyte presence increased tolerance to damage and boosted fitness. Folivory increased vertical transmission and hyphal density within seedlings, suggesting induced protection for progeny of damaged plants. Across natural populations, the prevalence of vertical transmission did not correlate with symbiont prevalence or differ with mode of transmission. Conclusions Herbivory not only mediated the reproductive fitness benefits of symbiosis, but also promoted symbiosis prevalence by increasing vertical transmission of the fungus to the next generation. Our results reveal a new mechanism by which herbivores could influence the prevalence of microbial symbionts in host populations.

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Variation in Recombination Rate Is Shaped by Domestication and Environmental Conditions in Barley

Molecular Biology and Evolution ◽

10.1093/molbev/msz141 ◽

2019 ◽

Vol 36 (9) ◽

pp. 2029-2039 ◽

Cited By ~ 4

Author(s):

Steven Dreissig ◽

Martin Mascher ◽

Stefan Heckmann

Keyword(s):

Environmental Conditions ◽

Recombination Rate ◽

Wild Barley ◽

Natural Populations ◽

Recombination Rates ◽

Distal Chromosome ◽

Positive Linear Correlation ◽

Short And Long Term ◽

Underlying Mechanisms ◽

Chromosome Regions

Abstract Meiotic recombination generates genetic diversity upon which selection can act. Recombination rates are highly variable between species, populations, individuals, sexes, chromosomes, and chromosomal regions. The underlying mechanisms are controlled at the genetic and epigenetic level and show plasticity toward the environment. Environmental plasticity may be divided into short- and long-term responses. We estimated recombination rates in natural populations of wild barley and domesticated landraces using a population genetics approach. We analyzed recombination landscapes in wild barley and domesticated landraces at high resolution. In wild barley, high recombination rates are found in more interstitial chromosome regions in contrast to distal chromosome regions in domesticated barley. Among subpopulations of wild barley, natural variation in effective recombination rate is correlated with temperature, isothermality, and solar radiation in a nonlinear manner. A positive linear correlation was found between effective recombination rate and annual precipitation. We discuss our findings with respect to how the environment might shape effective recombination rates in natural populations. Higher recombination rates in wild barley populations subjected to specific environmental conditions could be a means to maintain fitness in a strictly inbreeding species.

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Supplementation of Underfed Twin-Bearing Ewes with Herbal Vitamins C and E: Impacts on Birth Weight, Postnatal Growth, and Pre-Weaning Survival of the Lambs

Animals ◽

10.3390/ani10040652 ◽

2020 ◽

Vol 10 (4) ◽

pp. 652

Author(s):

Víctor H. Parraguez ◽

Francisco Sales ◽

Oscar A. Peralta ◽

Eileen Narbona ◽

Raúl Lira ◽

...

Keyword(s):

Birth Weight ◽

Environmental Conditions ◽

Postnatal Growth ◽

Vitamin Supplementation ◽

Growth And Survival ◽

Maternal Undernutrition ◽

Nutritional Strategy ◽

Total Antioxidant ◽

Positive Effect ◽

Natural Prairie

Twin-bearing pregnancies of sheep reared in harsh environmental conditions result in maternal undernutrition and feto-maternal oxidative stress, leading to intrauterine growth restriction (IUGR). We assessed the efficiency of supplementation with antioxidant herbal vitamins C and E alone or in combination with concentrate throughout gestation on pregnancy outcomes, pre-weaning growth, and survival of twin lambs from grazing ewes at the Magellan Steppe. Four groups (n = 30 each) of twin-bearing ewes received a base natural prairie (P) diet, supplemented with either herbal vitamins C 500 mg and E 350 IU per day (V) or concentrated food (S); groups were: P, P + V, P + S, and P + VS. Vitamins and concentrate were supplemented until parturition. At birth, lambs were weighed, and blood was drawn for total antioxidant capacity (TAC) evaluation. Lamb body weight (BW) and survival rate were evaluated at mid-lactation (60 days) and at weaning (120 days). Vitamin supplementation resulted in increased lamb birth weight and TAC, with a trend towards higher BW at weaning, while nutritional supplementation only had a positive effect on birth weight. Lamb survival was higher in both vitamin supplemented groups. In conclusion, supplementation with herbal vitamins C and E alone or in combination with concentrate food during pregnancy may constitute a good nutritional strategy for sheep reared in harsh environmental conditions.

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Warmer temperatures attenuate the classic offspring number and reproductive investment trade-off in the common lizard, Zootoca vivipara

Biology Letters ◽

10.1098/rsbl.2016.0101 ◽

2016 ◽

Vol 12 (6) ◽

pp. 20160101 ◽

Cited By ~ 10

Author(s):

Alexis Rutschmann ◽

Donald B. Miles ◽

Jean Clobert ◽

Murielle Richard

Keyword(s):

Life History ◽

Environmental Conditions ◽

Life History Traits ◽

Natural Populations ◽

Trade Off ◽

Offspring Number ◽

Common Lizard ◽

Trade Offs ◽

Zootoca Vivipara ◽

The Common

Life-history traits involved in trade-offs are known to vary with environmental conditions. Here, we evaluate the response of the trade-off between ‘offspring number’ versus ‘energy invested per offspring’ to ambient temperature in 11 natural populations of the common lizard, Zootoca vivipara . We provide evidence at both the intra- and interpopulation levels that the trade-off is reduced with an increase in air temperature. If this effect enhances current individual fitness, it may lead to an accelerated pace of life in warmer environments and could ultimately increase adult mortality. In the context of global warming, our results advocate the need for more studies in natural populations to explore interactions between life-history traits' trade-offs and environmental conditions.

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Fungal endophytes of Festuca rubra increase in frequency following long-term exclusion of rabbits

Botany ◽

10.1139/cjb-2014-0187 ◽

2015 ◽

Vol 93 (4) ◽

pp. 233-241 ◽

Cited By ~ 8

Author(s):

James S. Santangelo ◽

Nash E. Turley ◽

Marc T.J. Johnson

Keyword(s):

Plant Growth ◽

Intraspecific Competition ◽

Fungal Endophytes ◽

Natural Populations ◽

Fungal Endophyte ◽

Festuca Rubra ◽

Red Fescue ◽

Grass Endophyte ◽

Defensive Mutualism ◽

Endophyte Infection

Plant – fungal endophyte interactions are common in nature and they can shape the ecology of plants. Vertically transmitted endophytes are hypothesized to serve as mutualists, protecting plants from herbivores. If this hypothesis is true, then we expect endophytes to be most abundant in the presence of herbivores and least abundant in their absence, assuming endophytes incur a cost to their host. We tested this prediction by studying the effects of intense rabbit (Oryctolagus cuniculus Linnaeus) grazing on grass–endophyte interactions at Silwood Park, UK. We examined seeds of red fescue (Festuca rubra L.) collected from 15 natural populations that were protected from rabbits for 0.3–21 years. Contrary to our prediction, the mean proportion of seeds with endophytes increased 1.84×, from 0.45 to 0.83, following 21 years of rabbit exclusion. To better understand the mechanisms driving this increase in frequency, we conducted a fully factorial greenhouse experiment where we manipulated the presence or absence of endophyte infection, intraspecific competition, and simulated grazing on F. rubra plants. In both damaged and undamaged treatments, infected plants produced approximately twice as much biomass as uninfected plants, and endophytes did not influence tolerance to herbivory. These results suggest that endophytes directly change plant growth but not compensatory responses to damage. In the absence of competitors, infected plants produced 2.17× more biomass than uninfected plants, whereas in the presence of competitors, infected plants produced only 1.55× more biomass than uninfected plants. This difference suggests that intraspecific competition might lessen the benefits of endophyte infection. Our results do not support the defensive mutualism hypothesis, but instead suggest that endophyte-induced plant growth is important in shaping the costs and benefits of endophytes in our system.

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