What is the Difference Between Myxomycota and Oomycota

Myxomycota and Oomycota are two distinct groups within the kingdom of Fungi, each exhibiting unique characteristics and ecological roles. Understanding the differences between Myxomycota and Oomycota is crucial for recognizing their diverse contributions to ecosystems and their impact on various industries.

What is the difference between Myxomycota and oomycota? Myxomycota belongs to the Protist kingdom, whereas oomycote belongs to the Chromista kingdom. 

Key Areas Covered

1. What is Myxomycota
     – Definition, Facts, Features
2. What is Oomycota
     – Definition, Facts, Features
3. Similarities Between Myxomycota and Oomycota
    – Outline of Common Features
4. Difference Between Myxomycota and Oomycota
    – Comparison of Key Differences
5. FAQ – Myxomycota and Oomycota
    – Answers to Frequently Asked Questions

Key Terms  

Myxomycota, Oomycota

What is Myxomycota

Myxomycota refers to true slime molds or plasmodial slime molds, which are members of the kingdom Protista. They occur in nature as a plasmodium. Hence, they contain a blob of protoplasm without a cell wall. Therefore, only the cell membrane keeps everything in. Also, they primarily engulf bacteria. Their feeding behavior resembles a giant amoeba engulfing its food with pseudopodia. Then, they digest food inside the cell. The process is called phagocytosis. 

Figure 1: Comatricha nigra (myxogastria) with Developing Fruiting Bodies (sporangia)

True fungi have a cell wall and digest food with exoenzymes. Furthermore, after running out of food, myxomycota form fruiting bodies. They are small, 1-4 mm in height, and the diameter can be 25 cm.  

What is Oomycota

Oomycota refers to water mold and downy mildews with more than 500 species. They are filamentous protists, absorbing food from the surrounding water and soil. They play an essential role in the decomposition and recycling of decaying matter. Further, oomycota refer to egg fungi with a large round oogonia. They contain female gametes.

Figure 2: Late Blight on Potato Leaf

Although oomycetes show filamentous growth like a fungus, the cell wall does not contain chitin. It is made up of a mix of cellulosic compounds and glycan. Within the filaments, diploid nuclei occur with two sets of genetic information. In comparison, fungi contain haploid nuclei.    

Similarities Between Myxomycota and Oomycota 

1. Myxomycota and oomycote are two fungus-like organisms.
2. They belong to different kingdoms.

Difference Between Myxomycota and Oomycota

Definition

• Myxomycota refers to simple organisms that consist of creeping gelatinous protoplasm with nuclei or a mass of amoeboid cells, while oomycota refers to the phylum of fungus-like organisms in the kingdom Chromista.

Other Names

• True slime molds or plasmodial slime molds are other names for myxomycota, while water molds and downy mildews are the other names for oomycota.

Biological Classification

• Myxomycota belong to the Protist kingdom, while oomycota belong to the Chromista kingdom.

Characteristics

• Plasmodial properties and ameboid properties are characteristics of myxomycota, while filamentous growth and the production of oospores are the characteristic features of oomycota.

Function

• Myxomycota contain a plasmodial stage, forming spores, while oomycota exhibit filamentous growth and produce oospores.

Habitat

• Myxomycota often occur on decaying wood and plant material, while oomycota occur in aquatic or moist environments. 

Ecological Role

• Myxomycota are decomposers feeding on microorganisms, while oomycota are pathogens of plants and fish. 

Conclusion

In brief, Myxomycota and oomycota are two fungus-like organisms belonging to different kingdoms. Myxomycota belongs to the protist kingdom. They contain a plasmodial stage, forming spores. Also, they grow on decaying wood and plant material. Furthermore, they feed on microorganisms. On the other hand, oomycota belong to the chormista kingdom. They exhibit filamentous growth and produce spores. They live in aquatic or moist environments. Oomycota are pathogens of plants and fish. Therefore, the main difference between myxomycota and oomycota is their characteristics.   

FAQ: Myxomycota and Oomycota

1. How do myxomycota differ from true fungi?

Myxomycota or slime molds ingest food and digest it. In comparison, true fungi have a cell wall. Therefore, they digest their food by exonucleases before ingesting it. 

2. What is the difference between Oomycota and true fungi?

Oomycota contains mitochondria, which contain tubular cristae and protoplasmic and nuclear-associated microtubules. In comparison, true fungi contain flattened mitochondrial cristae. 

3. What are the characteristics of Oomycota?

The mycelium of oomycota does not contain cross-walls composed of cellulose, amino acid, and hydroxyproline. The cell walls of oomycote do not contain chitin. They produce oospores and zoospores. They cause many root rots, seeding diseases, foliar blights, and downy mildew. 

4. What is the fundamental difference between myxomycota and eumycota? 

The primary difference between myxomycota and eumycota is that myxomycota are fungi-like slime mold with no cell walls in the vegetative state, while eumycota is true fungi, which are filamentous eukaryotic microorganisms with rigid cell walls.  

References:

1. Slime mould. An overview | ScienceDirect Topics.  
2. Introduction to the Oomycota. US Museum of Palaeontology.

Image Courtesy:

1. “Comatricha nigra 176600092” By Alexis Tinker-Tsavalas – Own Work (CC-BY 4.0) via Anatomy tool
2. “Late blight on potato leaf 2” By Luttysar – Own Work (CC-BY 3.0) via Commons Wikimedia