Persistence of plant-mediated microbial soil legacy effects in soil and inside roots

Abstract

Plant-soil feedbacks are shaped by microbial legacies previous plants leave in the soil. We tested the persistence of such soil legacies after subsequent colonization by the same or other plant species, and whether the microbiome created by the previous plant explains current plant growth. Legacies of previous plants were detectable in soil fungal communities several months after their removal while concomitantly the effect of the current plant amplified in time. Remarkably, bacterial legacies faded away rapidly in the soil and bacterial communities were selected strongly by plant currently growing in the soil. Both fungal and bacterial legacies wrought by the previous plant were conserved inside the root endophytic compartment of the current plant and these endophytes affected significantly the plant growth. Hence, microbial soil legacies present at the time of plant establishment play a vital role in shaping plant growth even as the composition gradually changes in the soil after subsequent plant colonization, as they are taken up as endophytes in the plant. This suggests that plant-soil feedbacks may be partly mediated by a relatively stable endophytic community acquired in early ontogeny while the effects of previous plants detected on soil microbiomes vary between organisms studied. We further show that plants growing in their own soils harbor different endophytic microbiomes than plants growing in soils with legacy of other plants and that especially grasses are sensitive to species specific fungal pathogens while all plant species have less endophytic Streptomycetes when growing in their own soil. In conclusion, we show that soil legacies wrought by previous plants can remain present in the soils and inside the roots for months, even when subsequent plants colonize the soil and that these legacies also substantially modulate the plant growth.

Positive and negative feedbacks drive aboveground traits in rare plant species

“…Our results not only confirm that rare species on average suffer stronger negative plant-soil feedbacks on biomass when grown in conspecific soils, but also show that the strength and direction of plant-soil feedbacks in rare species are mediated by positive feedbacks in ECM colonization in both closely and distantly related plant-conditioned soils. These results suggest that conspecific-conditioned soils may be lacking adequate levels of mycorrhizal mutualists, while incurring high levels of plant pathogens (Hannula et al 2021). Consequently, rare species productivity is inextricably tied to belowground mycorrhizal colonization, making rare species more susceptible (both positively and negatively) to soil conditioning effects such as legacy and priority effects as well as aboveand belowground species interactions (Nytko et al in review ).…”

“…Specifically, mutualistic ectomycorrhizal (ECM) fungi play an integral role in mediating the productivity and diversity of aboveground plant communities through facilitating shifts in nutrient availability as well as soil structure and stability across early, mid-, and late successional stages (Ka lucka & Jagodziński 2017;McMahen et al 2022;Zhao et al 2023Wang et al 2023. For example, Hannula et al (2021) found that while bacterial communities quickly respond to alterations in plant community composition, microbially mediated soil legacy effects remain after five months of succession. Similarly, McMahen et al (2022) found that plant succession is highly influenced by mycorrhizal dependence, with ECM plant hosts demonstrating higher seedling survival and biomass in early succession.…”

Drought neutralizes positive effects of long‐term grazing on grassland productivity through altering plant–soil interactions

“…Additionally, grazing may cause shifts in the abundances of pathogenic and beneficial soil fungi (Barto & Rillig, 2010;Chen, Zhang, et al, 2018), thereby modifying plant-fungal interactions. The changes in abiotic and biotic soil properties resulting from grazing can persist even after the perturbation has ceased, and are then referred to as grazinginduced soil legacies (Bever, 2003;Hannula et al, 2021;van der Putten et al, 2013). While there is increasing evidence that grazing can affect plant performance via grazing-induced soil legacy effects (Chen et al, 2017;Egelkraut et al, 2018;Kardol et al, 2014), the extent to which grazing-induced soil legacy effects are modified by climate change (e.g.…”

A snapshot of the root phenotyping landscape in 2021

“…They include image-based approaches using scanners, cameras and microscopes, as well as chemical abundance measurements based on infrared gas analysis, chromatography and mass spectrometry (van Dam & Bouwmeester, 2016; Atkinson et al ., 2019; Wasson et al ., 2020). Next-generation sequencing-based methods have also become very popular for characterising root-associated microbiota (Hannula et al ., 2021) and quantifying species proportions in mixed root samples (Wagemaker et al ., 2021). The diversity of approaches used in root phenotyping is illustrated in Fig.…”