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-;Mycorrizha: A comparison between Endomycorrizha and Ectomycorrizha+''';Mycorrizha - A comparison between Endomycorrizha and Ectomycorrizha'''
;Introduction to Mycorrhiza ;Introduction to Mycorrhiza
Hello everyone! I still have to reference these findings, as well as finish this section. This is just a start to my brainstorming process. Thanks! Brianne Taylor Hello everyone! I still have to reference these findings, as well as finish this section. This is just a start to my brainstorming process. Thanks! Brianne Taylor

Revision as of 17:01, 15 March 2013

;Mycorrizha - A comparison between Endomycorrizha and Ectomycorrizha

Introduction to Mycorrhiza

Hello everyone! I still have to reference these findings, as well as finish this section. This is just a start to my brainstorming process. Thanks! Brianne Taylor


"Mycor" - "rhiza" is derived from the Greek words meaning "fungus" - "root" [1]. This symbiotic relationship occurs underground between the fungi and the root system of vascular plants. Mycorrhiza colonize in host plant root systems either intracellularly(endomycorrhiza) or extracellularly(ectomycorrhiza). Commonly, upon invasion a mutualistic relationship is established in which hundreds of thousands of mycelial branches are extended into the soil to allow uptake of phosphorous spanning over a large area. However, occasionally upon invasion a pathogenic relationship is established

Image:Endomycorrhiza.jpg Image:Ectomycorrhiza.jpg

Contents

Endomycorrihza

Endomycorrizha are also known as arbuscular mycorrihizal (AM) fungi and are generally classified in the Zygomycota phylum[2] However, AM fungi lack the production of zygospores, which is a main and common characteristic of all fungi within Zygomycota. Therefore, according the AFTOL, AM fungi are apart of the Glomeromycota phylum.[3]

Habitat

Endomycorrihza are most abundant in areas where there is a massive decline in soil nutrients that is accessible to the vegetation. This is due to their purpose of invading hosts plants and aiding in nutrient retrieval. Moreover, Endomycorrihza can be considered as ecologically important for most vascular plants and is found in 85% of plant families, most of them being crop species[4] [5]

Reproduction and Growth

Life Cycle

To date, there is no evidence that proves that AM fungi produce sexually. Molecular genetic markers show that there is little to no recombination from different lineages, therefore supporting the notion that AM fungi reproduce asexually [6].

Image:AMcycle.jpg This diagram dipicts the life cycle of AM fungi. The starting point is the germinating spore, which then either grows infection structures known as appresoria or grows hyphae from root to explore soil. The appresoria move on the surface of host roots and forms hyphae between cells that penetrate cell walls [7]. This is one of the main reasons why AM fungi are not detrimental to the host plant because the hyphae grow only within the external membrane. These hyphae form coils or tree-like structures called arbuscules.

Image:insideroot.jpg

From this new classification, AM fungi are characterized by their relatively large multi-nucleated spores that range from 40-800µm in diameter.

Biochemical Pathways

Applications

Genetics

Current Studies

Ectomycorrihza

Habitat

Reproduction and Growth

Life Cycle

Biochemical Pathways

Applications

Genetics

Current Studies

Comparison Table

Environmental concerns

Acid Rain

Acid rain is formed in the upper atmosphere as NO3 and SO2 are hydrolyzed [8] mixing with rain water and eventually falling back down to earth. Mycorrhizal associations can be affected either indirectly or through influence on host shoots. [9] Acid rain can have differeing effects on different species, one particular ECM fungi ascomycetes Cenococcum spp. has been reported to be more abundant in forests that have under gone acidification, most likely due to decreased competition from other species of fungi.[10] The problem of acid rain is often compounded as an increase in PH leads to an increase in the rate that minerals dissolve such as toxic heavy metals. [11]


Head 2

Extra Information

Plant species that benefit from Endomycorrizha and Ectomycorrizha[1]

References

[12]

[13]

[14]

  1. Frank, A. B. (1885). "Über die auf Würzelsymbiose beruhende Ehrnährung gewisser Bäum durch unterirdische Pilze". Berichte der Deutschen Botanischen Gesellschaft 3: 128–145.
  2. Moore, D., Robinsion, G.D., & Trinci, A.P. (2011) 21st Century Guidebook to Fungi. Cambridge University Press, New York.
  3. Moore, D., Robinsion, G.D., & Trinci, A.P. (2011) 21st Century Guidebook to Fungi. Cambridge University Press, New York.
  4. Gederman, H. A. Rev. Phytopath. 6, 397−418 (1968).
  5. Wang, B.; Qiu, Y.L. (2006). "Phylogenetic distribution and evolution of mycorrhizas in land plants". Mycorrhiza 16 (5): 299–363. doi:10.1007/s00572-005-0033-6. PMID 16845554. Retrieved 2008-01-21.
  6. Moore, D., Robinsion, G.D., & Trinci, A.P. (2011) 21st Century Guidebook to Fungi. Cambridge University Press, New York.
  7. Shchar-hil Lab doi:http://shachar-hill.plantbiology.msu.edu/?page_id=44
  8. Charlson, R.J., Rodhe, H., 1982. Factors controlling the acidity of natural rainwater. Nature 295, 683-685
  9. Cairney,J. Meharg,A. Influences of anthropogenic pollution on mycorrhizal fungal.Environmental Pollution 106 (1999) 169-182
  10. Danielson, R.M., Visser, S., 1989. Ef€fects of forest soil acidification on ectomycorrhizal and vesicular-arbuscular mycorrhizal development. New Phytologist 112, 41±47
  11. Cairney,J. Meharg,A. Influences of anthropogenic pollution on mycorrhizal fungal.Environmental Pollution 106 (1999) 169-182
  12. Frank, A. B. (1885). "Über die auf Würzelsymbiose beruhende Ehrnährung gewisser Bäum durch unterirdische Pilze". Berichte der Deutschen Botanischen Gesellschaft 3: 128–145.
  13. Author, 2013
  14. Author2, 2014
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