Diverse communities of fungal endophytes reside in plant tissues, where they affect and are affected
by plant physiology and ecology. For these intimate interactions to form and persist, endophytes and
their host plants engage in intricate systems of communication. The conversation between fungal
endophytes and plant hosts ultimately dictates endophyte community composition and function
and has cascading effects on plant health and plant interactions. In this review, we synthesize our
current knowledge on the mechanisms and strategies of communication used by endophytic fungi
and their plant hosts. We discuss the molecular mechanisms of communication that lead to organ
specificity of endophytic communities and distinguish endophytes, pathogens, and saprotrophs. We
conclude by offering emerging perspectives on the relevance of plant-endophyte communication to
microbial community ecology and plant health and function.
more »
« less
Elevated carbon dioxide reduces a common soybean leaf endophyte
Free‐air CO2enrichment (FACE) experiments have elucidated how climate change affects plant physiology and production. However, we lack a predictive understanding of how climate change alters interactions between plants and endophytes, critical microbial mediators of plant physiology and ecology. We leveraged the SoyFACE facility to examine how elevated [CO2] affected soybean (
- NSF-PAR ID:
- 10450146
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Global Change Biology
- Volume:
- 27
- Issue:
- 17
- ISSN:
- 1354-1013
- Page Range / eLocation ID:
- p. 4154-4168
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
more » « less
Abstract Fungal endophytes are critical members of the plant microbiome, but their community dynamics throughout an entire growing season are underexplored. Additionally, most fungal endophyte research has centred on seed‐reproducing hosts, while spore‐reproducing plants also host endophytes and may be colonized by unique community members. In order to examine annual fungal endophyte community dynamics in a spore‐reproducing host, we explored endophytes in a single population of ferns,
Polystichum munitum , in the Pacific Northwest. Through metabarcoding, we characterized the community assembly and temporal turnover of foliar endophytes throughout a growing season. From these results, we selected endophytes with outsized representations in sequence data and performedin vitro competition assays. Finally, we inoculated sterile fern gametophytes with dominant fungi observed in the field and determined their effects on host performance. Sequencing demonstrated that ferns were colonized by a diverse community of fungal endophytes in newly emerged tissue, but diversity decreased throughout the season leading to the preponderance of a single fungus in later sampling months. This previously undescribed endophyte appears to abundantly colonize the host to the detriment of other microfungi. Competition assays on a variety of media types failed to demonstrate that the dominant fungus was competitive against other fungi isolated from the same hosts, and inoculation onto sterile fern gametophytes did not alter growth compared to sterile controls, suggesting its effects are not antagonistic. The presence of this endophyte in the fern population probably demonstrates a case of repeated colonization driving competitive exclusion of other fungal community members. -
null (Ed.)Endophytes are microbes that live, for at least a portion of their life history, within plant tissues. Endophyte assemblages are often composed of a few abundant taxa and many infrequently observed, low-biomass taxa that are, in a word, rare. The ways in which most endophytes affect host phenotype are unknown; however, certain dominant endophytes can influence plants in ecologically meaningful ways—including by affecting growth and immune system functioning. In contrast, the effects of rare endophytes on their hosts have been unexplored, including how rare endophytes might interact with abundant endophytes to shape plant phenotype. Here, we manipulate both the suite of rare foliar endophytes (including both fungi and bacteria) and Alternaria fulva–a vertically transmitted and usually abundant fungus–within the fabaceous forb Astragalus lentiginosus. We report that rare, low-biomass endophytes affected host size and foliar %N, but only when the heritable fungal endophyte (A. fulva) was not present. A. fulva also reduced plant size and %N, but these deleterious effects on the host could be offset by a negative association we observed between this heritable fungus and a foliar pathogen. These results demonstrate how interactions among endophytic taxa determine the net effects on host plants and suggest that the myriad rare endophytes within plant leaves may be more than a collection of uninfluential, commensal organisms, but instead have meaningful ecological roles.more » « less
-
more » « less
Abstract Endophytes are microbes that live, for at least a portion of their life history, within plant tissues. Endophyte assemblages are often composed of a few abundant taxa and many infrequently observed, low-biomass taxa that are, in a word, rare. The ways in which most endophytes affect host phenotype are unknown; however, certain dominant endophytes can influence plants in ecologically meaningful ways—including by affecting growth and immune system functioning. In contrast, the effects of rare endophytes on their hosts have been unexplored, including how rare endophytes might interact with abundant endophytes to shape plant phenotype. Here, we manipulate both the suite of rare foliar endophytes (including both fungi and bacteria) and Alternaria fulva–a vertically transmitted and usually abundant fungus–within the fabaceous forb Astragalus lentiginosus. We report that rare, low-biomass endophytes affected host size and foliar %N, but only when the heritable fungal endophyte (A. fulva) was not present. A. fulva also reduced plant size and %N, but these deleterious effects on the host could be offset by a negative association we observed between this heritable fungus and a foliar pathogen. These results demonstrate how interactions among endophytic taxa determine the net effects on host plants and suggest that the myriad rare endophytes within plant leaves may be more than a collection of uninfluential, commensal organisms, but instead have meaningful ecological roles.
-
Chiang, Tzen-Yuh (Ed.)more » « less
Eukaryotic hosts harbor tremendously diverse microbiomes that affect host fitness and response to environmental challenges. Fungal endophytes are prominent members of plant microbiomes, but we lack information on the diversity in functional traits affecting their interactions with their host and environment. We used two culturing approaches to isolate fungal endophytes associated with the widespread, dominant prairie grass
Andropogon gerardii and characterized their taxonomic diversity using rDNA barcode sequencing. A randomly chosen subset of fungi representing the diversity of each leaf was then evaluated for their use of different carbon compound resources and growth on those resources. Applying community phylogenetic analyses, we discovered that these fungal endophyte communities are comprised of phylogenetically distinct assemblages of slow- and fast-growing fungi that differ in their use and growth on differing carbon substrates. Our results demonstrate previously undescribed and cryptic functional diversity in carbon resource use and growth in fungal endophyte communities ofA .gerardii .
