TY - JOUR

T1 - Carbon investment into mobilization of mineral and organic phosphorus by arbuscular mycorrhiza

AU - Andrino, Alberto

AU - Guggenberger, Georg

AU - Sauheitl, Leopold

AU - Burkart, Stefan

AU - Boy, Jens

N1 - Funding Information: The authors would like to thank Dr. Axel Don and Dr. Reinhard Well for opening the doors of the Th?nen Institute for developing part of the experiment. The authors are also thankful for the great help and guidance received by Dr. Norman Gentsch, Silke Bokeloh, Elke Eichmann-Prusch, Anne Katrin Herwig, Ulrike Pieper, Heike Steffen, and Michael Klatt. Raw and derived data supporting the findings of this study are available from the corresponding author Alberto Andrino on request.

PY - 2021/1

Y1 - 2021/1

N2 - To overcome phosphorus (P) deficiency, about 80% of plant species establish symbiosis with arbuscular mycorrhizal fungi (AMF), which in return constitute a major sink of photosynthates. Information on whether plant carbon (C) allocation towards AMF increases with declining availability of the P source is limited. We offered orthophosphate (OP), apatite (AP), or phytic acid (PA) as the only P source available to arbuscular mycorrhiza (AM) (Solanum lycopersicum x Rhizophagus irregularis) in a mesocosm experiment, where the fungi had exclusive access to each P source. After exposure, we determined P contents in the plant, related these to the overall C budget of the system, including the organic C (OC) contents, the respired CO2, the phospholipid fatty acid (PLFA) 16:1ω5c (extraradical mycelium), and the neutral fatty acid (NLFA) 16:1ω5c (energy storage) at the fungal compartment. Arbuscular mycorrhizal (AM) plants incorporated P derived from the three P sources through the mycorrhizal pathway, but did this with differing C-P trading costs. The mobilization of PA and AP by the AM plant entailed larger mycelium infrastructure and significantly larger respiratory losses of CO2, in comparison with the utilization of the readily soluble OP. Our study thus suggests that AM plants invest larger C amounts into their fungal partners at lower P availability. This larger C flux to the AM fungi might also lead to larger soil organic C contents, in the course of forming larger AM biomass under P-limiting conditions.

AB - To overcome phosphorus (P) deficiency, about 80% of plant species establish symbiosis with arbuscular mycorrhizal fungi (AMF), which in return constitute a major sink of photosynthates. Information on whether plant carbon (C) allocation towards AMF increases with declining availability of the P source is limited. We offered orthophosphate (OP), apatite (AP), or phytic acid (PA) as the only P source available to arbuscular mycorrhiza (AM) (Solanum lycopersicum x Rhizophagus irregularis) in a mesocosm experiment, where the fungi had exclusive access to each P source. After exposure, we determined P contents in the plant, related these to the overall C budget of the system, including the organic C (OC) contents, the respired CO2, the phospholipid fatty acid (PLFA) 16:1ω5c (extraradical mycelium), and the neutral fatty acid (NLFA) 16:1ω5c (energy storage) at the fungal compartment. Arbuscular mycorrhizal (AM) plants incorporated P derived from the three P sources through the mycorrhizal pathway, but did this with differing C-P trading costs. The mobilization of PA and AP by the AM plant entailed larger mycelium infrastructure and significantly larger respiratory losses of CO2, in comparison with the utilization of the readily soluble OP. Our study thus suggests that AM plants invest larger C amounts into their fungal partners at lower P availability. This larger C flux to the AM fungi might also lead to larger soil organic C contents, in the course of forming larger AM biomass under P-limiting conditions.

KW - Apatite

KW - Arbuscular mycorrhiza

KW - Inorganic phosphorus

KW - NLFA 16:1ω5c

KW - Organic phosphorus

KW - Photosynthesis

KW - Phytate

KW - PLFA 16:1ω5c

KW - Stable carbon isotopes

UR - http://www.scopus.com/inward/record.url?scp=85090064957&partnerID=8YFLogxK

U2 - 10.1007/s00374-020-01505-5

DO - 10.1007/s00374-020-01505-5

M3 - Article

AN - SCOPUS:85090064957

VL - 57

SP - 47

EP - 64

JO - Biology and fertility of soils

JF - Biology and fertility of soils

SN - 0178-2762

IS - 1

ER -