Colonized Root

(100X)

Root Lacking Colonization

(100X)

INVESTIGATION OF SALTMARSH PLANTS FOR THE PRESENCE OF MYCORRHIZAL FUNGI

1 Mississippi Gulf Coast Community College-Jackson County Campus, Gautier, MS 2 University of Southern Mississippi, Gulf Coast Research Laboratory, Ocean Springs, MS

LITERATURE CITED

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INVAM. 2007. http://invam.caf.wvu.edu

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Memphis, Tennessee.

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Microbiology 81:7-14.

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and Principles of Mycorrhizal Research. American Phytopathological Society. pp 69-76

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Community Development, Division Marine Fish. North Carolina Special Scientific Report 40, Morehead City.87p.

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Proceedings of the National Academy of Sciences 77: 2113–2118.

Mason E. 1928. Note on the presence of mycorrhizae in the roots of salt marsh plants. New Phytologist 27: 193–195.

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mycorrhiza in the salt marsh environment. Acta Botanica Neerlandica 35: 457–467.

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(India). Plant and Soil 122: 111–113.

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and Hammond LC. Eds. Westview Press, Boulder, CO. pp.144–167.

Tobar RM, Azcon R, Barea JM. 1994. Improved nitrogen uptake and transport from 15 N-labeled nitrate by external hyphae of arbuscular mycorrhiza

under water-stressed conditions. New Phytologist 126: 119–122.

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americana. Estuaries 17: 206–215.

ACKNOWLEDGMENTS

The authors would like to thank Dr. L. Melton (MGCCC) and Dr. S. Brown (USM) for assistance with coordinating this project and Diana

Reid (GCRL) for poster printing assistance.

RESULTS AND DISCUSSIONThe roots of the plants collected from the marsh behind GCRL were all found to be colonized with AMF, whereas plants collected from other locations were not colonized.

One of the benefits of AMF is an increase in nutrient uptake. In infertile soils, nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction. The results of this study suggest

that the areas of marsh behind GCRL may be low in nutrients as all plants were colonized with AMF, whereas the areas along the shoreline may be higher in nutrients as none of these plants were colonized

with AMF. Further studies, including analysis of the sediment, are required to confirm this.

ABSTRACTCoastal saltmarshes provide protection from erosion and hurricane damage, and offer nursery habitats for

ecologically and commercially important marine species. However, the total acreage of saltmarsh is in rapid

decline worldwide. This poses many problems, commercially and environmentally. Continued loss of saltmarsh

habitats could lead to a dwindling number of important commercial fisheries, as well as many other forms of

marine life. The number of saltmarsh restoration projects is on the rise, but the success rate of these projects is

only around fifty percent. Therefore, new methods are being developed to increase the health of plants grown in

nurseries, such as the root colonization of emergent vegetation by symbiotic mycorrhizal fungi. The colonization

of saltmarsh plants by certain species of mycorrhizal fungi could lead to improved nutrient uptake and therefore

better health of saltmarsh plants in the nursery. Samples of native marsh sediment and roots from the dominant

emergent vegetation species of the Gulf Coast, Spartina alterniflora, were collected and investigated for the

presence of these fungi. The amount of naturally occurring mycorrhizal fungi found at different coastal saltmarsh

sites was then compared.

INTRODUCTIONSaltmarsh communities are a common sight along the intertidal zone of Louisiana and Mississippi

coastlines. Saltmarshes are important vegetated habitats that are preferentially utilized by a multitude of species

as juvenile nursery areas, and therefore these areas are classified as essential fish habitat. Saltmarshes however

are declining, with 73% of the nation's estuaries moderately or severely degraded between 1940 and 1983 alone

(Mercer 1984). This is primarily due to human activities on land, boating, land reclamation and other construction

in the coastal zone, dredge-and-fill activities and destructive fisheries practices (Mitch and Gosselink 2000). The

loss of these valuable habitats gives urgency to protect, conserve and restore these important resources. In

efforts to overcome the loss of these valuable habitats, salt marsh restoration projects are on the increase. We

plan to investigate the role of symbiotic root association in fungi. These symbiotic fungi form associations with

roots of plants and are known as arbuscular mycorrhizal fungi (AMF). Nutrients taken up by AMF can lead to

improved plant growth and reproduction (Harley and Smith 1983, Allen 1992). Generally, with AMF associations

there is a benefit to both plant and fungi: the fungi obtain photosynthate from the host plant and the plant benefits

from added surface area for nutrient uptake (Hoefnagels et al 1993). Additionally, AMF may improve resistance to

pathogens, and enhance plant survival in stressful environments including: transplant shock (Dehne 1982,

Linderman and Hendrix 1982), water-stress (Tobar et al. 1994), salinity stress (Allen and Cunningham 1983), and

low nutrient availability (Wigand and Stevenson 1994). As such, plants with AMF are often more competitive and

better able to survive (Sylvia 1990). AMF occur in nearly 80% of terrestrial plant communities (Read et al 1976,

Malloch et al 1980, Harley and Smith 1983), but have rarely been studied in saltmarsh plants (Wigand and

Stevenson 1994). AMF were presumed absent from waterlogged or submersed habitats (Harley and Smith

1983), but they have been found in saltmarsh plants in several countries including Pakistan (Khan 1974), India

(Sengupta and Chaudhri 1990), France (Boullard 1985), Great Britain (Mason 1928) and the Netherlands

(Rozema et al. 1986). They are thought to assist plants during times of psychological stress (Hoefnagels et al

1993, Burke et al 2002). Kandalepas and Platt (2006) found that the majority of saltmarsh plants that perished

during Hurricane Katrina were not infected with AMF prior to the storm, whereas those that survived the hurricane

showed signs of AMF infection both before and after the storm, suggesting that AMF associations can survive

hurricanes and may play a critical role in saltmarsh plant survival. The interaction between AMF and saltmarsh

plants is an understudied area that has many implications for future restoration efforts.

MATERIALS AND METHODSThe entire plant and roots of Spartina alterniflora were collected from various locations in Davis Bayou in the

Mississippi Sound, including along the shoreline of East Beach, as well as from the marsh behind the Gulf Coast

Research Laboratory. The plants were returned to the lab and stored in the dark at 4C. Root samples were then

cleaned, cut and stained in ink and vinegar following the procedures of Vierheilig et al (1998). Using this method,

the chitin in fungal cell walls stains blue-black, while plant material remains hyaline/reddish-brown. Root samples

were examined using light microscopy to detect the presence of fungi.

Cutting roots from Spartina alterniflora plantsCollecting Spartina alterniflora plants

Saltmarsh Collection Sites

Staining procedure

Collected Spartina alterniflora plant

ready for cutting

Staining procedure

Beach 2 siteMaking collections behind the Caylor building at the

Gulf Coast Research Laboratory, Ocean Springs, MS

Table 1 Collecting Locations

Caylor 1 site

Aimie Chambliss1, Melissa Adriano2, Allison K. Walker2 and Jinx Campbell2

Root Staining Procedure

Gulf Coast Research Laboratory

Caylor 7 site

Pier site

Date Location Mycorrhizal Status (+/-)

10/23/2008 East Beach Negative

10/23/2008 Caylor Marsh Positive

11/6/2008 East Beach Negative

11/6/2008 Pier Negative

11/6/2008 Caylor Marsh Positive

1/27/2009 Caylor Marsh Positive