Ectomycorrhizae and Endomycorrhizae

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A symbiotic mutual relationship between plant and a fungus is known as mycorrhiza. Mycorrhizae mean fungus- root. The fungus helps in water and nutrient uptake in the plant and simultaneously plant act as food and nutrients supplier to the fungus.

Ectomycorrhizae and Endomycorrhizae
Mycorrhizae

Types of  Mycorrhizae

  1. Ectomycorrhizae
  2. Endomycorrhizae – It includes
  • Ericoid mycorrhizas
  • Orchid mycorrhizas

Ectomycorrhizae

Ectomycorrhizae and Endomycorrhizae
AM mycorrhiza
  • Ectomycorrhiza (ECM) can be described as a mutualistic association of fungi with roots of higher plants
  • Higher plants include certain families of woody gymnosperms likePinaceae, angiosperms like Dipterocarpaceae,  birch, dipterocarp, eucalyptus, oak, pine, and rose families.
  • Majority ECM synthesizing fungi belong to the classes Basidiomycetes and Ascomycetes.
  • ECM associations contribute to around 30 per cent of the microbial biomass in forest soil
  • These fungi counted to about least 6000 species.
  • These are considered as major organisms in nutrient and carbon cycles in forest ecosystems
  • It is characterized by the presence of a fungal mantle or sheath that covers the host roots and a Hartig net that surrounds root cortical or epidermal cells.
  • This provides a large intercellular space through which minerals and nutrient materials are exchanged between the fungus and the plant.
  • The colonization of root tips by ECM can lead to suppression of root hair development by hormonal interactions like cytokinins which result in increased branching.
  • The fungal hyphae also give their characteristic colour to the mycorrhizal root surface.
  • Pines and larches can produce a new type of mycorrhiza having characteristics of both ectomycorrhizae and arbuscular mycorrhizae called ectendomycorrhiza.
Ectomycorrhizae and Endomycorrhizae
Ectomycorrhizae

Endomycorrhizae (Arbuscular (AMs) mycorrhizas)

Endomycorrhizae is a mutual relationship between a plant and root fungi in which the hyphae of the fungus penetrates into the cells of the root.

  •  AM mycorrhizas are soil fungi belonging to the phylum Glomeromycota.
  •  It is characterised by the formation of arbuscules, or tree-shaped structures
  • Most endomycorrhizae contain both vesicles and arbuscules and are, therefore, called vesicular-arbuscular mycorrhizae.
  • Endomycorrhizae isn’t surrounded by a dense fungal mantle but by a loose mycelial growth on the root surface from which hyphae and large pearl-covered zygospores or chlamydospores are produced underground.
  • Endomycorrhizae is also produced by some basidiomycetes.
  • These are obligate symbionts and have the less saprophytic ability.
  • Plant for their carbon nutrition required to them.
  • AM fungi are mostly associated with angiosperms, gymnosperms, pteridophytes, and bryophytes.
  • Arbuscules facilitate the exchange of materials between plant and fungal symbionts.
  • These are modified fungal hyphae which provide a large surface area for resource exchange.
  • Most AM have storage structures called vesicles that store oil-rich products.
  • It is known that these help plants to capture major nutrients such as phosphorus and micronutrients from the soil.
  • Ex- Glomus
Ectomycorrhizae and Endomycorrhizae
Endomycorrhizae, Arrow indicates rhizomorphs

Endomycorrhizas is divided based on the host plants and nature of the symbiosis-

  1. Ericoid mycorrhizas- It is a restricted group of fungi associated with Ericaceae, Epacridaceae, and Empetraceae.
  2. Orchid mycorrhizas- The orchid roots and mycorrhizas are associated with subdivision Ascomycotina and the Deuteromycotina.

References

  1. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/ectomycorrhizae
  2. https://www.sciencedirect.com/topics/immunology-and-microbiology/ectomycorrhiza
  3. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/endomycorrhizae
  4. https://www.sciencedirect.com/topics/immunology-and-microbiology/arbuscular-mycorrhiza
  5. https://link.springer.com/chapter/10.1007/978-94-017-2498-2_4