TY - JOUR
T1 - Plant−fungal symbiosis responds to experimental addition of resources and physical stressor in a salt marsh
AU - Moore, Althea F.P.
AU - Gehring, Catherine A.
AU - Hughes, A. Randall
N1 - Funding Information:
We thank Erica Holdridge, Robyn Zerebecki, Austin Heil, and Forest Schenk for assistance in the field and lab. Funding was provided by NSF grants DEB-0928279 and IOS-1556738 to A.R.H. We thank Florida State University Marine and Coastal Laboratory and Northeastern University Marine Science Center for institutional support. This is contribution no. 415 from the Northeastern University Marine Science Center.
Funding Information:
Acknowledgements. We thank Erica Holdridge, Robyn Zerebecki, Austin Heil, and Forest Schenk for assistance in the field and lab. Funding was provided by NSF grants DEB-0928279 and IOS-1556738 to A.R.H. We thank Florida State University Marine and Coastal Laboratory and North-eastern University Marine Science Center for institutional support. This is contribution no. 415 from the Northeastern University Marine Science Center.
Publisher Copyright:
© Inter-Research 2021.
PY - 2021
Y1 - 2021
N2 - Plant−fungal symbioses can have strong consequences for ecological communities and are sensitive to variation in abiotic factors. While the functions of mycorrhizal fungi are well established, the role of other root-colonizing fungi such as dark septate endophytes (DSE), which lack specialized structures for nutrient transfer, are less clear. DSE are ubiquitous in extreme and stressful ecosystems, including marine environments, and some studies suggest a potential role in plant nutrition. However, the response of DSE to nutrient availability and physical stress has rarely been tested in the field. We conducted a 10 mo field experiment to investigate how a symbiosis between the salt marsh plant Spartina alterniflora and DSE fungi responded to increased resources (nutrient addition) and physical stress (salt addition). Plant stem density and height increased in response to nutrient enrichment, consistent with past experiments in nutrient-limited marsh systems. Nutrient additions also increased S. alterniflora percent cover, but this effect was negated with elevated salinity. Nutrient addition decreased colonization by DSE hyphae by nearly half (8.8%, vs. 15.7% at ambient levels). Nutrients did not decrease DSE microsclerotia, which were marginally increased with the combination of added nutrients and salinity. These results are consistent with the view that plant−DSE interactions are based in part on enhanced nutritional condition of plants by fungi. In addition, there was a positive relationship between plant shoot growth and root colonization by DSE, suggesting a benefit of the association for the plants. Our results suggest that the poorly understood plant−DSE symbioses may be important in intertidal environments.
AB - Plant−fungal symbioses can have strong consequences for ecological communities and are sensitive to variation in abiotic factors. While the functions of mycorrhizal fungi are well established, the role of other root-colonizing fungi such as dark septate endophytes (DSE), which lack specialized structures for nutrient transfer, are less clear. DSE are ubiquitous in extreme and stressful ecosystems, including marine environments, and some studies suggest a potential role in plant nutrition. However, the response of DSE to nutrient availability and physical stress has rarely been tested in the field. We conducted a 10 mo field experiment to investigate how a symbiosis between the salt marsh plant Spartina alterniflora and DSE fungi responded to increased resources (nutrient addition) and physical stress (salt addition). Plant stem density and height increased in response to nutrient enrichment, consistent with past experiments in nutrient-limited marsh systems. Nutrient additions also increased S. alterniflora percent cover, but this effect was negated with elevated salinity. Nutrient addition decreased colonization by DSE hyphae by nearly half (8.8%, vs. 15.7% at ambient levels). Nutrients did not decrease DSE microsclerotia, which were marginally increased with the combination of added nutrients and salinity. These results are consistent with the view that plant−DSE interactions are based in part on enhanced nutritional condition of plants by fungi. In addition, there was a positive relationship between plant shoot growth and root colonization by DSE, suggesting a benefit of the association for the plants. Our results suggest that the poorly understood plant−DSE symbioses may be important in intertidal environments.
KW - Dark septate endophyte
KW - Endophyte
KW - Environmental stress
KW - Microsclerotia
KW - Mutualism
KW - Nutrients
KW - Resource availability
KW - Root associated fungi
KW - Salt marsh
KW - Spartina alterniflora
UR - http://www.scopus.com/inward/record.url?scp=85149268549&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85149268549&partnerID=8YFLogxK
U2 - 10.3354/meps13614
DO - 10.3354/meps13614
M3 - Article
AN - SCOPUS:85149268549
SN - 0171-8630
VL - 661
SP - 115
EP - 125
JO - Marine Ecology - Progress Series
JF - Marine Ecology - Progress Series
ER -