Arbuscular Mycorrhizal Arbuscular Mycorrhizal Fungi Exhibit No Fungi Exhibit No

Significant Change in Significant Change in Producing Glomalin Producing Glomalin Under Varying Water Under Varying Water

TreatmentsTreatmentsBy Sherry DarabiBy Sherry Darabi

Faculty Sponsor: Dr. Kathleen Faculty Sponsor: Dr. Kathleen TresederTreseder

Mitigation of Climate Mitigation of Climate ChangeChange

Global warming Global warming is a current is a current concern.concern.

Atmospheric COAtmospheric CO22 contributes to contributes to global warming. global warming.

AMF may AMF may ameliorate ameliorate climate change climate change by producing by producing glomalin with glomalin with the carbon in the carbon in COCO22..

Atmospheric CO2

Plants

AMF

Glomalin

What are AMF and What are AMF and Glomalin?Glomalin?

AMF invade root AMF invade root cells and transfer cells and transfer nutrients to the nutrients to the plant in exchange plant in exchange for the plant’s for the plant’s carbon.carbon.

AMF use a AMF use a portion of the portion of the carbon to carbon to produce a produce a tough, sticky tough, sticky glycoprotein glycoprotein called glomalin.called glomalin.

Atmospheric CO2

Plants

AMF

Glomalin

Global Warming

AtmosphericPrecipitation

CO2

Glomalin

+

+

_

_

The Big Picture

HypothesisHypothesis

I predicted that I predicted that the the more more precipitationprecipitation a a plant is exposed plant is exposed to, the to, the more more glomalinglomalin AMF AMF will produce to will produce to prevent nutrient prevent nutrient leakage.leakage.

Materials and MethodsMaterials and Methods

grew annual grew annual ryegrass under ryegrass under four differing four differing watering watering treatments for 5 treatments for 5 weeksweeks

cut, dried, and cut, dried, and weighed shootsweighed shoots

cleaned, dried, and cleaned, dried, and weighed rootsweighed roots

400 mL/week

300 mL/week

500 mL/week

600 mL/week

x 8 x 8

x 8

x 8

Materials and MethodsMaterials and Methods

protein protein extractions for extractions for each sampleeach sample

Bradford Bradford protein assay protein assay and ELISAand ELISA

Glomalin Glomalin concentration concentration

Shoot Weight- Significant Shoot Weight- Significant CorrelationCorrelation (P<0.001)(P<0.001)

Average Shoot Weight

0

0.3

0.6

0.9

1.2

300 400 500 600

Water Treatment (mL)

Sh

oo

t W

eig

ht

(g)

Root Weight- No Significant Root Weight- No Significant ChangeChange(P= 0.540)(P= 0.540)

Average Root Weight

0

2

4

6

8

300 400 500 600

Water Treatment (mL)

Ro

ot

Weig

ht

(g)

Glomalin- No Significant Glomalin- No Significant CorrelationCorrelation

(P=0.611)(P=0.611)Glomalin Concentration

0

0.3

0.6

0.9

1.2

1.5

300 400 500 600

Water Treatment (mL)

Glo

mal

in C

once

ntra

tion

(mg/

g of

soi

l)

ConclusionConclusion

My data did not support My data did not support Wright’s hypothesis that AMF Wright’s hypothesis that AMF produce glomalin to prevent produce glomalin to prevent nutrient leaching, since nutrient leaching, since glomalin production and glomalin production and water availability were water availability were notnot significantly related.significantly related.

ConclusionConclusion

Shoot biomass did not seem to Shoot biomass did not seem to influence glomalin production.influence glomalin production.

It is difficult to draw conclusions It is difficult to draw conclusions regarding root biomass and glomalin regarding root biomass and glomalin concentration, since neither varied concentration, since neither varied significantly among treatments.significantly among treatments.

Alternative Mechanisms- predation, Alternative Mechanisms- predation, byproduct, temperature regulatorbyproduct, temperature regulator

I thank Dr. Kathleen Treseder and Katie Turner for all their

help and support.