Mycorrhizal fungi

Definition

Mycorrhizal fungi are a type of fungus that forms a symbiotic relationship with the roots of plants, enhancing nutrient uptake, particularly phosphorus and nitrogen. This partnership allows plants to access essential nutrients from the soil while providing the fungi with carbohydrates produced through photosynthesis. This mutualistic relationship is vital for plant health and soil ecology.

5 Must Know Facts For Your Next Test

1. Mycorrhizal fungi can increase phosphorus absorption by up to 90%, which is crucial for plant growth and development.
2. These fungi help improve soil structure and aeration, making it easier for roots to grow and access water.
3. Mycorrhizal associations can enhance a plant's resistance to diseases by promoting healthier root systems.
4. Different plant species may form specific types of mycorrhizal relationships, influencing plant diversity in ecosystems.
5. The presence of mycorrhizal fungi in the soil can significantly improve ecosystem resilience, especially under environmental stressors like drought.

Review Questions

• How do mycorrhizal fungi enhance nutrient uptake for plants, and what specific nutrients are primarily involved?
  • Mycorrhizal fungi enhance nutrient uptake for plants primarily by increasing the surface area of roots through their extensive hyphal networks. This allows plants to absorb more nutrients from the soil, especially phosphorus and nitrogen, which are often limited in availability. The relationship benefits both parties, as plants provide carbohydrates to the fungi while receiving critical nutrients necessary for their growth.
• Discuss the different types of mycorrhizal associations and their specific roles in plant nutrient acquisition.
  • There are two main types of mycorrhizal associations: ectomycorrhizae and endomycorrhizae. Ectomycorrhizae form a sheath around root tips and are commonly associated with trees like pines and oaks, helping them access nutrients in nutrient-poor soils. Endomycorrhizae penetrate the root cells and form arbuscules within them, commonly found in many herbaceous plants. Both types play crucial roles in enhancing nutrient absorption, but they cater to different plant needs based on their habitat.
• Evaluate the ecological significance of mycorrhizal fungi in maintaining healthy ecosystems and supporting biodiversity.
  • Mycorrhizal fungi play a critical role in maintaining healthy ecosystems by improving soil structure, enhancing nutrient cycling, and increasing plant resilience to environmental stressors. Their ability to promote diverse plant communities helps stabilize soils and supports various organisms within the ecosystem. The interaction between plants and mycorrhizal fungi facilitates nutrient availability for a wide range of species, thus fostering biodiversity and ensuring ecosystem stability against disturbances such as climate change and land degradation.

Related terms

Symbiosis: A close and long-term interaction between two different biological species, often benefiting both parties involved.

Ectomycorrhizae: A type of mycorrhizal association where the fungal hyphae form a sheath around the root tips, commonly found in trees like pines and oaks.

Endomycorrhizae: A type of mycorrhizal association where fungal hyphae penetrate the root cells, forming structures called arbuscules, often found in many herbaceous plants.