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Dryad

Plant choice between arbuscular mycorrhizal fungal species results in increased plant P acquisition

Cite this dataset

Weber, Sören; Bascompte, Jordi; Kahmen, Ansgar; Niklaus, Pascal (2024). Plant choice between arbuscular mycorrhizal fungal species results in increased plant P acquisition [Dataset]. Dryad. https://doi.org/10.5061/dryad.v15dv421p

Abstract

Arbuscular mycorrhizal fungi (AMF) are plant root symbionts that provide phosphorus (P) to plants in exchange for photosynthetically fixed carbon (C). Previous research has shown that plants – given a choice among AMF species – may preferentially allocate C to AMF species that provide more P. However, these investigations rested on a limited set of plant and AMF species, and it therefore remains unclear how general this phenomenon is. Here, we combined 4 plant and 6 AMF species in 24 distinct plant-AMF species compositions in split-root microcosms, manipulating the species identity of AMF in either side of the root system. Using 14C and 32P/33P radioisotope tracers, we tracked the transfer of C and P between plants and AMF, respectively. We found that when plants had a choice of AMF species, AMF species which transferred more P acquired more C. Evidence for preferential C allocation to more beneficial AMF species within individual plant roots was equivocal. However, AMF species which transferred more P to plants did so at lower C-to-P ratios, highlighting the importance both of absolute and relative costs of P acquisition from AMF. When plants had a choice of AMF species, their shoots contained a larger total amount of P at higher concentrations. Our results thus highlight the benefits of plant C choice among AMF for plant P acquisition.

README: Overview

We grew plants in split root microcosms and manipulated the arbuscular mycorrhizal fungal (AMF) species identity in both sides of these microcosms. Our intent was to evaluate whether a common mechanism of symbiotic control among plant species is the preferential allocation of carbon (C) to higher quality AMF species when plants have options of AMF species in separate parts of their root systems.

biomass_and_nutrients.csv


Plant biomass (dry) as total and partitioned into nutrients, both fractional and total nutrient content for phosphorus (P) and nitrogen (N). Data are given for each species pool and the associated plant species x AMF species compositions

Description of the data and file structure

Variable Description units
pool pool of plant and AMF species used n/a
plantsp plant species genus names n/a
amfcomp AMF species composition n/a
choice Whether plants have choice between two AMF species or are restricted to interact with a single AMF species n/a
mass Shoot biomass of the host plant g
pfrac Fractional P content of host plant shoot biomass g/g
nfrac Fractional P content of host plant shoot biomass g/g
totp Total P content of host plant shoot biomass mg
totn Total N content of host plant shoot biomass mg

Factor levels

plantsp Description
holcus Holcus lanatus
lolium Lolium multiflorum
plantago Plantago lanceolata
trifolium Trifolium pratense
amf* Description
fm Funneliformis mosseae
gd Glomus diaphanum
sc Septoglomus constrictum
cc Claroideoglomus claroideum
dc Diversispora celata
ri Rhizophagus invermaius

*This applies equally to amf_focal, amf_opposite and amfcomp

choice Description
choice Plants have two different AMF species in the spatially separated portions of their root systems
no_choice Plants have the same exact AMF species in the spatially separated portions of their root systems

GCA.csv


We estimated the quality of AMF species associated with our host plants in order to assess whether plants allocated more C (measured as 14C) to higher quality AMF. We achieved this via a mechanical diallel approach, taken from biodiversity experiments. We estimated general combining ability (GCA) for each plant x AMF species, for both total P (i.e. P acquired potential via direct root P uptake + AMF P uptake mechanism) and radiolabeled P (either 32or33P; i.e. P acquired via AMF P uptake mechanism)

Description

Variable Description units
pool pool of plant and AMF species used n/a
plantsp plant species genus names n/a
amf AMF species n/a
totp_gca Total plant shoot P general combining ability (GCA), estimate of AMF species quality. Estimated for each plant species x AMF species combination. mg
p_gca Radiolabeled shoot P (either 32 or 33P; acquired from AMF transfer) general combining ability (GCA), estimate of AMF species quality. Estimated for each plant species x AMF species combination. kBq (kilobecquerels)

Factor levels

plantsp Description
holcus Holcus lanatus
lolium Lolium multiflorum
plantago Plantago lanceolata
trifolium Trifolium pratense
amf* Description
fm Funneliformis mosseae
gd Glomus diaphanum
sc Septoglomus constrictum
cc Claroideoglomus claroideum
dc Diversispora celata
ri Rhizophagus invermaius

*This applies equally to amf_focal, amf_opposite and amfcomp

radioisotopes.csv


Radioactive isotopic tracers applied to plants and associated arbuscular mycorrhizal fungi (AMF) within a split root microcosm. Our intent was to identify patterns of resource transfer (plant carbon (C) and AMF phosphorus (P)) between several different combinations of plant hosts and AMF species (between 1 and 2 species).

Description

Variable Description units
pool pool of plant and AMF species used n/a
plantsp plant species genus names n/a
amf_focal focal AMF species n/a
amf_opposite AMF species in opposing side of the microcosm n/a
amfcomp AMF species composition n/a
c 14C transferred to focal AMF species kBq (kilobecquerels)
p 32 or 33P transferred from focal AMF species to plant kBq (kilobecquerels)
cp 14C:32/33P, i.e. C transferred from plants to focal AMF species relative to P acquired from focal AMF species kBq (kilobecquerels)

Factor levels

plantsp Description
holcus Holcus lanatus
lolium Lolium multiflorum
plantago Plantago lanceolata
trifolium Trifolium pratense
amf* Description
fm Funneliformis mosseae
gd Glomus diaphanum
sc Septoglomus constrictum
cc Claroideoglomus claroideum
dc Diversispora celata
ri Rhizophagus invermaius

*This applies equally to amf_focal, amf_opposite and amfcomp

Funding

Zurich-Basel Plant Science Center, Award: Syngenta Fellowship Program of the Zurich-Basel Plant Science Center to Pascal Niklaus, Jordi Bascompte, and Ansgar Kahmen

University of Zurich, Award: Forschungskredit FK-21-106