Home-field advantage? evidence of local adaptation among plants, soil, and arbuscular mycorrhizal fungi through meta-analysis.
Local adaptation, the differential success of genotypes in their native versus foreign environment, arises from various evolutionary processes, but the importance of concurrent abiotic and biotic factors as drivers of local adaptation has only recently been investigated. Local adaptation to biotic interactions may be particularly important for plants, as they associate with microbial symbionts that can significantly affect their fitness and may enable rapid evolution. The arbuscular mycorrhizal (AM) symbiosis is ideal for investigations of local adaptation because it is globally widespread among most plant taxa and can significantly affect plant growth and fitness. Using meta-analysis on 1170 studies (from 139 papers), we investigated the potential for local adaptation to shape plant growth responses to arbuscular mycorrhizal inoculation.



The magnitude and direction for mean effect size of mycorrhizal inoculation on host biomass depended on the geographic origin of the soil and symbiotic partners. Sympatric combinations of plants, AM fungi, and soil yielded large increases in host biomass compared to when all three components were allopatric. The origin of either the fungi or the plant relative to the soil was important for explaining the effect of AM inoculation on plant biomass. If plant and soil were sympatric but allopatric to the fungus, the positive effect of AM inoculation was much greater than when all three components were allopatric, suggesting potential local adaptation of the plant to the soil; however, if fungus and soil were sympatric (but allopatric to the plant) the effect of AM inoculation was indistinct from that of any allopatric combinations, indicating maladaptation of the fungus to the soil.



This study underscores the potential to detect local adaptation for mycorrhizal relationships across a broad swath of the literature. Geographic origin of plants relative to the origin of AM fungal communities and soil is important for describing the effect of mycorrhizal inoculation on plant biomass, suggesting that local adaptation represents a powerful factor for the establishment of novel combinations of fungi, plants, and soils. These results highlight the need for subsequent investigations of local adaptation in the mycorrhizal symbiosis and emphasize the importance of routinely considering the origin of plant, soil, and fungal components.
Department of Biology, University of Mississippi, P.O. Box 1848, University, 38677, MS, USA. megan.rua@nimbios.org.|National Institute for Mathematical and Biological Synthesis, University of Tennessee, 1122 Volunteer Blvd, Knoxville, TN, 37996-3410, USA. megan.rua@nimbios.org.
Megan A
MA
Rúa
School of Forestry, Northern Arizona University, 200 E. Pine Knoll, Flagstaff, AZ, 86011, USA.
Anita
A
Antoninka
Department of Biology, Algoma University, 1520 Queen Street East, Sault Ste. Marie, ON, P6A 2G4, Canada.
Pedro M
PM
Antunes
Department of Environmental Science and Studies, DePaul University, McGowan South Suite 203, 1110 West Belden Avenue, Chicago, IL, 60614, USA.
V Bala
VB
Chaudhary
Department of Biological Sciences, Northern Arizona University, 617 S. Beaver Street, Flagstaff, AZ, 86011-5640, USA.
Catherine
C
Gehring
School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931-1295, USA.
Louis J
LJ
Lamit
Department of Biology, University of Mississippi, P.O. Box 1848, University, 38677, MS, USA.
Bridget J
BJ
Piculell
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA.
James D
JD
Bever
Department of Land Resources and Environmental Sciences, Montana State University, 344 Leon Johnson Hall, Bozeman, MT, 59717, USA.
Cathy
C
Zabinski
Institute of Ecology and Evolution, University of Oregon, 335 Pacific Hall, Eugene, OR, 97403, USA.
James F
JF
Meadow
Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, Tampa, FL, 33620, USA.
Marc J
MJ
Lajeunesse
Department of Biology, New Mexico State University, Las Cruces, NM, 88003, USA.
Brook G
BG
Milligan
Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
Justine
J
Karst
Department of Biology, University of Mississippi, P.O. Box 1848, University, 38677, MS, USA.
Jason D
JD
Hoeksema
D000064:Acclimatization; D000222:Adaptation, Physiological; D018533:Biomass; D017753:Ecosystem; D038821:Mycorrhizae / Q000145:classification*; D018521:Plant Physiological Phenomena; D018517:Plant Roots; D012987:Soil; D012988:Soil Microbiology; D013559:Symbiosis
D012987:Soil
Arbuscular mycorrhizal fungi; Community ecology; Evolution; Geographic origin; Local adaptation; Soil micro-organisms; Symbiosis