What is the Difference Between Ectomycorrhizae and Endomycorrhizae

The main difference between ectomycorrhizae and endomycorrhizae is that the hyphae of the ectomycorrhizae form a sheath around the root from the outside, whereas the hyphae of the endomycorrhizae enter the cells of the root.

Ectomycorrhizae and endomycorrhizae are two types of mycorrhizal fungi, which are the symbiotic fungi with the roots of plants. Ectomycorrhizae form a Hartig net between the cells in the root cortex while endomycorrhizae forms branched hyphae called arbuscles inside the cells in the root cortex. 

Key Areas Covered 

1. What is Ectomycorrhizae
     – Definition, Structure, Importance
2. What is Endomycorrhizae
     – Definition, Structure, Importance
3. What are the Similarities Between Ectomycorrhizae and Endomycorrhizae
     – Outline of Common Features
4. What is the Difference Between Ectomycorrhizae and Endomycorrhizae
     – Comparison of Key Differences

Key Terms 

Arbuscules, Ectomycorrhizae, Endomycorrhizae, Hartig Net, Mycorrhizae, Symbiosis

What is Ectomycorrhizae 

Ectomycorrhizae (ECM) is one of the two types of mycorrhizal fungi that form symbiotic relationships with the roots of plants. However, it is less common, and only 10% of plant families form symbiotic associations with ectomycorrhizae. These include birch, dipterocarp, eucalyptus, oak, pine, and rose families. Mainly, Basidiomycota, Ascomycota, and Zygomycota are the fungal phyla that serve as mycorrhizae. 

Figure 1: Ectomycorrhizae

Furthermore, the main characteristic feature of ectomycorrhizae is that it produces a Hartig net, surrounding the root. Generally, it is a fungal sheath or a mantle, mainly covering the root tips. Moreover, fungal hyphae of mycorrhizae surround the cells in the root cortex through their extracellular spaces. From the outside, fungal hyphae also form an extensive network with the soil and leaf litter.  

What is Endomycorrhizae 

Endomycorrhizae is another type of mycorrhizae fungi forming the symbiotic relationships with the root.  The main characteristic feature of this type of fungi is that they penetrate the cells in the root cortex. Arbuscular, ericoid, arbutoid, monotropoid, and orchid mycorrhizas are the different types of endomycorrhizae. From these, arbuscular mycorrhizae (AM) are the most common form. Generally, 70% of the mycorrhizal fungi are arbuscular mycorrhizae. However, the main characteristic feature of this arbuscular mycorrhizae is the formation of unique structures such as arbuscules and vesicles by fungi.

Figure 2: Arbuscular Mycorrhiza

Moreover, arbuscular mycorrhizae belong to the phylum Glomeromycota. Scientists believe that the formation of arbuscular mycorrhizal symbiosis played a crucial role in the initial colonization of land plants, as well as the evolution of vascular plants. However, the main role of these fungi in their symbiotic relationship is to provide water and minerals to the plant. They also obtain sugars from the roots.

Similarities Between Ectomycorrhizae and Endomycorrhizae

• Ectomycorrhizae and Endomycorrhizae are two types of mycorrhizal fungi. 
• They maintain symbiotic relationships with the roots of plants. 
• They also obtain sugars produced by plants through photosynthesis. 
• Moreover, they produce water and mineral nutrients to the plant, including phosphors. 
• Some plant families such as Brassicaceae and Chenopodiaceae do not produce mycorrhizal associations. 
• Furthermore, bryophytes produce mycorrhizae-like associations. 

Difference Between Ectomycorrhizae and Endomycorrhizae

Definition 

Ectomycorrhizae refers to a symbiotic relationship of fungi with plants; wherein, the hyphae of the fungus forms a sheath around the outside of the plant root and grows between the plant cells to exchange nutrients. On the other hand, endomycorrhizae refers to a symbiotic relationship with plants wherein the hyphae of the fungus enters into the cells of a plant root to exchange nutrients. Hence, this is the main difference between ectomycorrhizae and endomycorrhizae.

Colonization 

Another difference between ectomycorrhizae and endomycorrhizae is that ectomycorrhizae are extracellular colonization, while endomycorrhizae form intracellular colonization. 

Occurrence 

Moreover, ectomycorrhizae is less common, while endomycorrhizae is more common. 

Fungal Phyla 

Basidiomycota, Ascomycota, and Zygomycota serve as ectomycorrhizae, while Glomeromycota serves as endomycorrhizae. 

Produce  

Moreover, ectomycorrhizae produce a Hartig net between the cells in the root cortex, while endomycorrhizae produces branched hyphae called arbuscles inside the cells in the root cortex. Thus, this is also a difference between ectomycorrhizae and endomycorrhizae.

Types 

Arbutoid mycorrhiza is a type of ectomycorrhizae while arbuscular, ericoid, and orchid mycorrhiza is the types of endomycorrhizae. 

Conclusion 

Ectomycorrhizae is a type of mycorrhizal fungi, producing Hartig net around the root of plants. Therefore, it does not penetrate the cells of the root. However, it forms extracellular colonization. On the other hand, endomycorrhizae is another type of mycorrhizal fungi, penetrating the cells of the root. Therefore, it forms intracellular colonization with arbuscles. Thus, the main difference between ectomycorrhizae and endomycorrhizae is the method of colonization. 

References:

1. “Mycorrhiza.” Wikipedia, Wikimedia Foundation, 14 June 2019, Available Here.

Image Courtesy:

1. “Ectomycorrhiza illustration” By Atrebe10 – Own work (CC BY-SA 3.0) via Commons Wikimedia   
2.”Arbuscular mycorrhiza microscope” By Msturmel – MS Turmel, University of Manitoba, Plant Science Department (Public Domain) via Commons Wikimedia