Plant response to fungal root endophytes varies by host genotype in the foundation species Spartina alterniflora

Abstract

Plants and their interactions with root-associated fungi have wide-reaching ecological effects, from influencing individual traits to modifying interactions with other species to affecting biodiversity and biogeochemical cycles (Johnson et al., 2012). While mycorrhizal fungi have long been of interest, there is growing evidence that other root-associated fungi markedly influence host plant structural and physiological traits, particularly when mycorrhizal fungi are absent or in low abundance (Porras-Alfaro and Bayman, 2011; Clemmensen et al., 2013; Kivlin et al., 2013; Berthelot et al., 2019). Plant trait differences can result from functions provided by fungal endophytes, including the production of secondary metabolites with antibacterial properties and hormones that influence plant growth and biomass allocation (Andrade-Linares and Franken, 2013; Berthelot et al., 2019). Dark septate endophytes (DSE) are a polyphyletic fungal endophyte group with high colonization rates in the roots of a broad range of host plants in nearly all biomes (Mandyam and Jumpponen, 2008, 2014; Newsham, 2011) and with melanized hyphae that may allow them to withstand extreme conditions (Jumpponen and Trappe, 1998; Kivlin et al., 2013). Unlike mycorrhizal fungi, DSE do not have specialized structures for resource exchange with host plants, but their presence is associated with increased plant shoot nitrogen and phosphorus concentrations (Newsham, 2011). Recent genomic evidence suggests that DSE have a spectrum of enzymes capable of degrading organic matter (Knapp et al., 2018), consistent with an ability to increase nutrient availability to plants, particularly in nutrient-poor soils (Newsham, 2011; Knapp et al., 2018). Dark septate endophytes can also protect against plant pathogens (Andrade-Linares and

Ectomycorrhizal and Dark Septate Fungal Associations of Pinyon Pine Are Differentially Affected by Experimental Drought and Warming

“…The presence of melanized, septate hyphae and microsclerotia were used as indicators of DSE and quantified using the grid-line intersect method (McGonigle et al, 1990) using ~100 intersections per sample. Root samples were not stained as melanized hyphae were clearly visible without this step as observed in other study systems (Liu et al, 2017;Hughes et al, 2020). The remaining fine roots were stored at −20°C until molecular analysis of fungal communities.…”

No evidence that lulworthioid fungi are dark septate endophytes in the roots of the dominant Mediterranean seagrassPosidonia oceanica

“…Unlike P. atricolor , most of them are relatively easy to culture so they could be used in resynthesis experiments to reveal their actual colonization pattern, possibly with a model non-seagrass hosts, since many endophytes do not seem to be host specific. However, the experimental results available to date indicate negative effects of lulworthioid fungi on their host plants (Hughes et al . 2020).…”

Response to nitrogen and salinity in Rhizophora mangle propagules varies by maternal family and population of origin

“…In addition, we know very little about the interactions with the microbiome in the species, but microbes have been highlighted as important symbionts in these and other challenging environments (Bowen et al, 2017; Angermeyer et al, 2018; Jung et al, 2021). Soil microbial activity could have dramatic impacts on the future nutrient availability and stability of these coastal sediments (Deegan et al, 2012; Bowen et al, 2017; Hughes et al, 2020; Lewis et al, 2021). In fact, a recent study suggested that bacterial community composition differed among R. mangle maternal genotypes but not with genetic diversity (Craig et al, 2020).…”