Mutualism effectiveness and vertical transmission of symbiotic fungal endophytes in response to host genetic background

Gundel, Pedro E.; Martínez‐Ghersa, M. Alejandra; Omacini, Marina; Cuyeu, Romina; Pagano, Elba; Ríos, Raúl; Ghersa, Claudio M.

doi:10.1111/j.1752-4571.2012.00261.x

Cited by 65 publications

(71 citation statements)

References 49 publications

(101 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, our results contrast with inoculation experiments that observed reduced or abnormal growth of symbionts in novel hosts (Christensen 1995, Saikkonen et al ). On the other hand, our results are consistent with a previous study that found no change in endophyte transmission following experimental crosses between host populations (Gundel et al ). Collectively, the available literature and our new results suggest that experimental inoculation studies that force novel host–symbiont associations may over‐estimate the potential for genetic incompatibility relative to approaches that measure symbiont responses to ecologically realistic outcrossing events, particularly within the grass–endophyte system.…”

Section: Discussionsupporting

confidence: 94%

Does host outcrossing disrupt compatibility with heritable symbionts?

Sneck

Rudgers

Young

et al. 2019

Oikos

View full text Add to dashboard Cite

Vertically transmitted microbes are common in macro‐organisms and can enhance host defense against environmental stress. Because vertical transmission couples host and symbiont lineages, symbionts may become specialized to host species or genotypes. Specialization and contrasting reproductive modes of symbiotic partners could create incompatibilities between inherited symbionts and novel host genotypes when hosts outcross or hybridize. Such incompatibilities could manifest as failed colonization or poor symbiont growth in host offspring that are genetically dissimilar from their maternal host. Moreover, outcrossing between host species could influence both host and symbiont reproductive performance. We tested these hypotheses by manipulating outcrossing between populations and species of two grasses, Elymus virginicus and E. canadensis, that host vertically transmitted fungal endophytes (genus Epichloё). In both greenhouse and field settings, we found that host–symbiont compatibility was robust to variation in host genetic background, spanning within‐population, between‐population and between‐species crosses. Symbiont transmission into the F1 generation was generally high and weakly affected by host outcrossing. Furthermore, endophytes grew equally well in planta regardless of host genetic background and transmitted at high frequencies into the F2 generation. However, outcrossing, especially inter‐specific hybridization, reduced reproductive fitness of the host, and thereby the symbiont. Our results challenge the hypothesis that host genetic recombination, which typically exceeds that of symbionts, is a disruptive force in heritable symbioses. Instead, symbionts may be sufficiently generalized to tolerate ecologically realistic variation in host outcrossing.

show abstract

Section: Discussionsupporting

confidence: 94%

Does host outcrossing disrupt compatibility with heritable symbionts?

Sneck

Rudgers

Young

et al. 2019

Oikos

View full text Add to dashboard Cite

show abstract

“…Grasses containing endophytes may be increasingly important in the face of climate changes because the symbiosis between plant and endophyte provides increased drought resistance and hardiness to the plant, and endophyte-grass interactions influence forage and pasture sustainability (Gundel et al, 2012). However, the monetary savings that may be gleaned by utilizing predominantly available forages may be negated by reduced milk production due to fescue toxicosis.…”

Section: Introductionmentioning

confidence: 99%

Consumption of endophyte-infected fescue seed during the dry period does not decrease milk production in the following lactation

Baldwin

Capuco

Evock‐Clover

et al. 2016

Journal of Dairy Science

View full text Add to dashboard Cite

Ergot alkaloids in endophyte-infected grasses inhibit prolactin (PRL) secretion and may reduce milk production of cows consuming these grasses. We investigated the effects of consuming endophyte-infected fescue seed during late lactation and the dry period on mammary growth, differentiation, and milk production. Twenty-four multiparous Holstein cows were randomly assigned to 3 treatment groups. Starting at 90±4 d prepartum, cows were fed endophyte-free fescue seed (control; CON), endophyte-free fescue seed plus 3×/wk subcutaneous injections of bromocriptine (0.1mg/kg of body weight, positive control; BROMO), or endophyte-infected fescue seed (INF) as 10% of the diet on an as fed basis. Although milk yield of groups did not differ before treatment, at dry off (-60 d prepartum) INF and BROMO cows produced less milk than CON. Throughout the treatment period, basal concentrations of PRL and the prepartum increase in plasma PRL were reduced in INF and BROMO cows compared with CON cows. Three weeks after the end of treatment, circulating concentrations of PRL were equivalent across groups. In the subsequent lactation milk yield was not decreased; in fact, BROMO cows exhibited a 9% increase in milk yield relative to CON. Evaluation of mammary tissue during the dry period and the subsequent lactation, by quantitative histology and immunohistochemical analysis of proliferation markers and putative mammary stem or progenitor cell markers, indicated that feeding endophyte-infected fescue seed did not significantly affect mammary growth and development. Feeding endophyte-infected grasses during the dry period may permit effective utilization of feed resources without compromising milk production in the next lactation.

show abstract

“…Similar to other mutualistic organisms, fungal endophytes also can alleviate pathogen and herbivore stress on plant hosts (Gundel et al 2012; Rodriguez et al 2009), but the mechanisms and ecological consequences are not well understood (see also Saikkonen et al 2013). …”

Section: Examples Of Plant-microbe Interactions That Alter Plant Phenmentioning

confidence: 99%

The Impact of Beneficial Plant-Associated Microbes on Plant Phenotypic Plasticity

et al. 2013

View full text Add to dashboard Cite

Plants show phenotypic plasticity in response to changing or extreme abiotic environments; but over millions of years they also have co-evolved to respond to the presence of soil microbes. Studies on phenotypic plasticity in plants have focused mainly on the effects of the changing environments on plants’ growth and survival. Evidence is now accumulating that the presence of microbes can alter plant phenotypic plasticity in a broad range of traits in response to a changing environment. In this review, we discuss the effects of microbes on plant phenotypic plasticity in response to changing environmental conditions, and how this may affect plant fitness. By using a range of specific plant-microbe interactions as examples, we demonstrate that one way that microbes can alleviate the effect of environmental stress on plants and thus increase plant fitness is to remove the stress, e.g., nutrient limitation, directly. Furthermore, microbes indirectly affect plant phenotypic plasticity and fitness through modulation of plant development and defense responses. In doing so, microbes affect fitness by both increasing or decreasing the degree of phenotypic plasticity, depending on the phenotype and the environmental stress studied, with no clear difference between the effect of prokaryotic and eukaryotic microbes in general. Additionally, plants have the ability to modulate microbial behaviors, suggesting that they manipulate bacteria, enhancing interactions that help them cope with stressful environments. Future challenges remain in the identification of the many microbial signals that modulate phenotypic plasticity, the characterization of plant genes, e.g. receptors, that mediate the microbial effects on plasticity, and the elucidation of the molecular mechanisms that link phenotypic plasticity with fitness. The characterization of plant and microbial mutants defective in signal synthesis or perception, together with carefully designed glasshouse or field experiments that test various environmental stresses will be necessary to understand the link between molecular mechanisms controlling plastic phenotypes with the resulting effects on plant fitness.

show abstract

Mutualism effectiveness and vertical transmission of symbiotic fungal endophytes in response to host genetic background

Cited by 65 publications

References 49 publications

Does host outcrossing disrupt compatibility with heritable symbionts?

Does host outcrossing disrupt compatibility with heritable symbionts?

Consumption of endophyte-infected fescue seed during the dry period does not decrease milk production in the following lactation

The Impact of Beneficial Plant-Associated Microbes on Plant Phenotypic Plasticity

Contact Info

Product

Resources

About