Mycelium in the PRV. I. Evolution of Land Plants Land plants arose from mutualistic relationships...

Mycelium in the PRV

I. Evolution of Land Plants

• Land plants arose from mutualistic relationships between fungi and green algae

• Evidence:– Over 90% of land plants have symbioses with

mycorrhizal fungi• Fungi: aid in water and nutrient uptake, • Plants provide fungi with sugars due to photosynthetic

ability– Incorporation of fungi into seeds– VAM associations revealed in palaeobotanical study– Genes required for mycorrhizal associations present in

ancestors of land plants

(Stamets, 2005) (Margulis & Fester Eds., 1991)(Wang et al., 2009) (Brundrett, 2002)

http://mycorrhizas.info/evolution/root-evolution.gif

II. Types of Fungi

1.Saprophytic: decomposers (soil builders)

Example in Potomac River Valley:(Stamets, 2005)

(Kuo, 2007)

http://michiganmushroomhunters.org/Images/morels/Black%20morel.jpg

Morels (black, yellow) can be saprophytic and also mycorrhizal

II. Types of Fungi2. Parasitic: inflict cankers/lesions on trees

Example: Phytophthora ramorum - causes sudden oak disease

Link to PRV: Oaks in PRV are

susceptible to this fungal pathogen

(Stamets, 2005)

(Virginia Bioinformatics Institute, 2004)

http://cisr.ucr.edu/sudden_oak_death.html

II. Types of Fungi3. Mycorrhizal: form

mutualisms with plants• Ectomycorrhizal-form

sheaths around the roots of partner plants

• Endomycorrhizal-invade interior root cells of host plants (also called vesicular arbuscular mycorrhizae, VAM

(Stamets, 2005) (Margulis & Fester Eds., 1991)

http://www.palaeos.com/Plants/Lists/Glossary/Images/Endomycorrhizae.gif

II. Types of Fungi• Benefits of mycorrhizal associations:

1. Increased length and surface area for absorption • Cool fact: Absorption capacity of mycorrhizal fungi may

be 10-100 times greater than SA of leaves in a forest(Stamets, 2005)

http://www3.ntu.edu.sg/home/mvvkulish/Image21.jpg

http://www.technion.ac.il/~mdcourse/274203/slides/Digestive%20tract/17-Intestinal%20villi%20Jejunum-A.jpg

http://course1.winona.edu/sberg/IMAGES/mito3.gif

http://www3.ntu.edu.sg/home/mvvkulish/Image21.jpg

II. Types of Fungi

(Johnson et al., 2006)

II. Types of Fungi

2. Nutrient sharing (one mushroom species can connect many acres of a forest in a continuous network of cells)

• Link to coevolution:• Possibility of fungi providing more nutrients

to a tree with which it forms a better mutualistic association (positive feedback)

(Stamets, 2005)


II. Types of Fungi

(Stamets, 2005)

Douglas Fir

Paper Birch

Western Red Cedar

Ectomycorrhizal

Endomycorrhizal

Nutrient Sharing

Shaded

II. Types of Fungi

• Example of nutrient sharing:• Douglas fir and paper birch connected by one type of

ectomycorrhizal fungi• Western Red Cedar in a mutualistic relationship with

a different type of mycorrhizae (a VAM)• Differential shading led to change in nutrient flow

(from birch to fir)• Amount of carbon transferred is directly related to

amount of shading• Possibly helps saplings survive under canopy? (Link

to dogwoods in PRV coming later!)

(Stamets, 2005)

II. Types of Fungi• Benefits

continued… 3. Resistance to

pests

4. Tolerance of extreme conditions

(Johnson et al., 2006) (Bouchez & Roncho, 2008)

II. Types of Fungi


• Benefits continued…5. Soil aggregation

6. Reduced erosion

II. Types of Fungi


• Benefits on different ecological scales:

II. Types of Fungi4. Endophytic: mutualistic fungi that live

inside plants• Ex: Endophytic fungi in grasses produce

mycotoxins that offer protection from grazers(Faeth, 2002)

http://www.ifsqn.com/images/cow.gif

III. Plants of the Potomac River Gorge and Surrounding Area

• Corridor of biodiversity

• Variety of seeds brought to PRV due to diverse ecosystems in watershed

• Gorge is surrounded by unique rock formations called “bedrock terraces”

• 1,400+ different kinds of plants grow in the Potomac Valley Gorge

(Cohen, 2005)


• Examples of herbaceous plants include wild columbine, golden rod lyre-leaved rock cress, Virginia blue bells, Dutchmen’s breeches, jewelweed and wild ramps (leeks)

• Examples of woody plants include white ash, red maple, sycamore, sugar maples, red & white oaks, hickory and flowering dogwoods

• Examples of woody shrub-like plants include hop hornbeam and bladdernut

(Cohen, 2005)


• What type of plant is this? (Game!)

(Cohen, 2005)

http://www.dcr.virginia.gov/natural_heritage/ncPIf.shtml

Hickory!



(Cohen, 2005)


Red Maple!



(Cohen, 2005)


Switch grass!



(Cohen, 2005)


Sycamore!



(Cohen, 2005)


Silver Maple!



(Cohen, 2005)


Western Sunflower!



(Cohen, 2005)


White Ash!



(Cohen, 2005)


White oak!



(Cohen, 2005)


Virginia Bluebells!

IV. PRV Mutualisms

• Mycorrhizae and tree mutualisms:– Cantharellus cibarius (ectomycorrhizal) and

Quercus rubra (Northern red oak)– Fraxinus americana (white ash) and morels

(many different species) (Stamets, 2005)

http://www.dcr.virginia.gov/natural_heritage/ncTIg.shtml

IV. PRV Mutualisms• Flowering Dogwood (Cornus florida) &

Fungi:– Mycorrhizal fungi allocate nutrients to dogwoods (an

understory tree) from canopy trees– Pathogenic fungi (Dogwood anthracnose or Discula

destructiva)

(Kuo, 2007)

http://www.dcr.virginia.gov/natural_heritage/ncTIIIc.shtml

(Carr & Banas, 2000)

IV. PRV Mutualisms• Mycorrhizae and herbaceous plants:

– Wild leeks (also called ramps) form mutualistic relationships with mycelium which promote leek health by:

• Bioremediation• Increasing surface area for water uptake• Changing physical and chemical properties of soil

(Leyval & Binet, 1998)

http://greayer.com/studiog/wp-content/uploads/2009/04/mosaic1602239.jpg

IV. PRV Mutualisms

• Fungal and animal mutualisms:– Gyrodon merulioides-a fungi found near white ash– Forms a mutualistic relationship with

Meliarhizophagus fraxinifolii (leafcurl ash aphid) – Fungi: form structures that surround/protect aphid– Aphids: provide honeydew to fungi (Kuo, 2007)

http://mycorrhizas.info/methods/ash-bolete-aphid.jpg

IV. PRV Mutualisms• Fungal and animal mutualisms:

– Marsh periwinkle and fungi:• Snail eats fungi and then defecates on marsh grass• Fungi break down marsh grass, snail returns and eats

fungi and digested marsh grass(Silliman & Newell, 2003)

http://www.frauleindi.com/images/HHNature/OurSaltMarsh-MarshPeriwinkles.jpg

V. Fungal Associations and History

• Example: Salem witch trials

• Thought questions:– Did mycorrhizal interactions affect the

formation of civilizations (dependence on agriculture)? If so, how?

– How will/does the use of fungicides affect agriculture?

– How can we apply our knowledge of fungal mutualisms to enhance crop production?

(Le Couteur & Burreson, 2003)


• How can we apply our knowledge of fungal mutualisms to enhance crop production?

– Example 1: Insect control• Production of mycotoxins by endophytes

can be used to kill insects. – Link to PRV: Could lead to decreased use of

insecticides.

(Stamets, 2005)


• How can we apply our knowledge of fungal mutualisms to enhance crop production?– Example 2: Microbial Control

• Application of endophytes to cocoa trees led to a decline in leaf necrosis (possible antimicrobial activity?)

• Application of an endophyte (called Piriformospora indica) to wheat plants caused an increase in biomass and seed production by protecting roots from pathogenic microorganisms

– Link to PRV: Could be biodefensive (antimicrobial) against fungus that causes sudden oak disease or the fungus that affects the dogwoods.

(Stamets, 2005)


• How can we apply our knowledge of fungal mutualisms to enhance crop production?– Example 3: Heat and Drought Tolerance

• Dusting wheat with extremophile endophytes from Yellowstone conferred increased drought resistance

• Barley associated with mycorrhizae grew better under poor conditions (drought, addition of xenobiotics) than barley without fungal associations

– Link to PRV: Could be used in fields surrounding the PRV which could promote increased yield due to tolerance of drought conditions and increased ability to produce biomass without fertilizers.

(Stamets, 2005)

(Khalvati et. al, 2009)

VI. Conserving the PRV

• Future and current threats to biodiversity of Potomac River Gorge plant species include (in order of impact):– 1. Development– 2. Invasion of non-native species (currently 273

exotic species grow within the gorge including English ivy and Japanese honeysuckle)

– 3. Overabundance of foraging deer (78 per square mile in VA, 40+ is considered too much)

– 4. Too many visitors (over 3.5 million each year)

(Cohen, 2005)


• Possible methods to conserve the PRV using fungi as a means of ecological restoration and facilitation:– Mycorestoratin through:

• Mycofiltration (purifying water)• Mycoforestry (ecoforestry policy)• Mycoremediation (denaturing toxic wastes)• Mycopesticides (controlling insect pests)

(Stamets, 2005)


• Problem 1: Fossil fuel emissions• Fossil fuels release polyaromatic hydrocarbons (PAHs) • One experiment found that increasing amounts of PAHs

in the soil decreased mycorrhizal colonization of plant roots

• The same experiment found that plants with mycorrhizal associations were able to survive and grow in soils with higher amounts of PAH than plants without these associations

(Leyval & Binet, 1998)(Bouchez et. al, 1995)


• Possible reasons for these findings include:– Mycorrhizae bioremediate through bacterial

recruitment and improving soil conditions– Bacteria that are recruited can use PAHs as a

source of carbon and thus break them down and detoxify them

– Link to PRV: Leeks (wild ramps in the PRV) were used in this study and could help detoxify fossil fuel emissions from major highways

(Leyval & Binet, 1998)(Bouchez et. al, 1995)

(Whelan & Rock, 2006)


• Problem 2: Input of nitrates into Chesapeake Bay:– One experiment found that Paxillus involutus,

a mycelium associated with Picea abies (Norway spruce) and (Betula pendula) silver birch increased nitrate assimilation (although it was affected by pH)

– Are there any mutualisms in the PRV that do this?

(Andersson et. al, 1994)

VII. Link to Final Product:

• How can we use mycorrhizae’s ability to bioremediate to decrease levels of pollutants at lower points in the PRV watershed in order to protect other kinds of symbioses found in the PRV?

References• Beltrano, J. & Ronco, M.G. (2008). Improved tolerance of wheat plants

(Triticum aestivum L.) to drought stress and rewatering by the arbuscular mycorrhizal fungus Glomus claroideum: effect on growth and cell

membrane stability. Braz. J. Plant Physiol. [online]. 20(1), 29-37 . Retrieved from:<http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100004&lng=en&nrm=iso>. ISSN 1677-0420. doi: 10.1590/S1677-04202008000100004.

• Bouchez, M., Blanchet, D., and Vandercasteele, J.P. (1995). “Degradation of polycyclic aromatic hydrocarbons by pure strains and by defined strain associations: inhibition phenomena and cometabolism.” Applied Microbiology and Biotechnology. 43.1: 156-164.

• Brundrett, M. C. (2002). Coevolution of roots and mycorrhizas of land plants. New

Phytologist, 154(2), 275-304.

• Carr, D. E., & Banas, L. E. (2000). Dogwood Anthracnose (Discula Destructiva): Effects of and Consequences for Host (Cornus Florida) Demography. American

Midland Naturalist, 143(1), 169-177.

• Cohen, J.P. (2005). “A wild river runs through Washington.” Smithsonian ZooGoer 34(6). Retrieved from:

http://nationalzoo.si.edu/Publications/ZooGoer/2005/6/potomac.cfm

References• Ek, H., Andersson, S., Arnebrant, K., & Söderström, B. (1994). Growth and

Assimilation of NH4 + and NO3 - by Paxillus involutus in Association with Betula pendula and Picea abies as Affected by Substrate pH. New

Phytologist, 128(4), 629-637.

• Faeth, S. H. (2002). Are endophytic fungi defensive plant mutualists? Oikos, 98(1), 25-36.

• Johnson, N. C., Jason D. Hoeksema, Bever, J. D., Chaudhary, V. B., Gehring, C., Klironomos, J., et al. (2006). “From Lilliput to Brobdingnag: Extending Models of Mycorrhizal Function across Scales.” BioScience, 56(11), 889-900.

• Khalvati, M., Bernadett, B., Dupigny, A. and Schroder, P. (2009). “Arbuscular mycorrhizal association is beneficial for growth and detoxification of xenobiotics of barley under drought stress.” Journal of Soils and Sediments JSS. 1.1: 54- 64.

• Kuo, M. (2007). Mushroom Expert.com. Retrieved from: http://www.mushroomexpert.com/trees/index.html

• Le Couteur P & Burreson J. (2003). Napoleon’s buttons: how 17 molecules changed history. New York(NY): Jeremy P. Tarcher/Putnam.

References• Leyval, C., and P. Binet. (1998). "Effect of polyaromatic hydrocarbons in soil on arbuscular

mycorrhizal plants." Journal of Environmental Quality 27.2: 402-7. Applied Science Full Text. Web. 13 Feb. 2010.

• Margulis, L., and R. Fester (Eds.). (1991). Symbiosis as a source of evolutionary innovation : speciation and morphogenesis. MIT Press, Cambridge Mass. Retrieved from: http://books.google.com/books?id=3sKzeiHUIUQC&printsec=frontcover#v=onepage&q= &f=false

• Silliman, B. R., & Newell, S. Y. (2003). Fungal Farming in a Snail. Proceedings of the National Academy of Sciences of the United States of America, 100(26), 15643-15648.

• Stamets, P. (2005). Mycelium running : how mushrooms can help save the world. Ten Speed Press, Berkeley Calif. Retrieved from: http://books.google.com/books?id=NPI8_omzvsC&dq=mycelium+running&printsec=frontcover&source=bn&hl=en&ei=2PN5S93XOZCqNpuayLQH&sa=X&oi=book_result&ct=res ult&resnum=6&ved=0CCIQ6AEwBQ#v=onepage&q=&f=false

• Virginia Bioinformatics Institute. (2004). “Researcher from VBI advances fight against sudden oak death disease.” Retrieved from:

https://www.vbi.vt.edu/public_relations/press_releases/sudden_oak_death_disease

• Wang, B., Yeun, L. H., Xue, J., Liu, Y., An, J., & Qiu, Y. (2009). Presence of three mycorrhizal genes in the common ancestor of land plants suggests a key role of mycorrhizas in the colonization of land by plants. New Phytologist, 9999(9999). Retrieved from: http://dx.doi.org/10.1111/j.1469-8137.2009.03137.x.

• Whelan A. & Rock, S. (2006). Phytotechnology Expediates Removal of Oil Waste from Shoreline Sediment.” EPA: Technology News and Trends. Retrieved from: http://www.cluin.org/products/newsltrs/tnandt/view.cfm?issue=0506.cfm#4

Mycelium in the PRV. I. Evolution of Land Plants Land plants arose from mutualistic relationships...

Documents

Transcript of Mycelium in the PRV. I. Evolution of Land Plants Land plants arose from mutualistic relationships...