Mycorrhiza

**Types of Mycorrhiza:**
– Ectomycorrhizas and endomycorrhizas are common types.
– Endomycorrhiza includes arbuscular, ericoid, and orchid mycorrhiza.
– Arbutoid mycorrhizas classified as ectoendomycorrhizas.
– Monotropoid mycorrhizas form a distinct category.
– Ectomycorrhizas involve fungi not penetrating individual root cells.

**Specific Mycorrhizal Associations:**
– Arbuscular mycorrhizas formed by fungi in the division Glomeromycota.
– Ericoid mycorrhiza involves intraradical growth in root cells.
– Orchid mycorrhiza where orchids are myco-heterotrophic.
– Monotropoid mycorrhiza occurs in certain plant subfamilies.
– Mutualist dynamics in mycorrhizal relationships across plant species.

**Benefits and Applications of Mycorrhizal Networks:**
– Mycorrhizal fungi aid plant growth in sterile soils and nutrient-deficient environments.
– Enhance plant defenses against insect attacks.
– Contribute to plant nutrition, phosphorus uptake, and ecosystem health.
– Used in agriculture for improved crop yield, disease suppression, and soil health.
– Play a crucial role in sustainable agriculture, forestry, and phytoremediation.

**Ecology and Mechanisms of Mycorrhizal Networks:**
– Mycorrhizal networks facilitate nutrient exchange, extend plant root reach, and improve resistance to pathogens.
– Crucial for plant health, soil fertility, nutrient cycling, and adaptation to environmental changes.
– Connect multiple plants in shared underground systems, contributing to biodiversity and ecosystem functioning.
– Signals in arbuscular mycorrhizal symbiosis enhance plant communication and defense mechanisms.
– Fungal networks transport signals to warn plants of threats and stabilize cooperation.

**Evolution, Occurrence, and Research of Mycorrhizal Networks:**
– Genetic evidence suggests ancient origins of mycorrhizae, with various types evolving at different periods.
– Mycorrhizas present in 92% of plant families studied, with arbuscular mycorrhizas being predominant.
– Human activities impact mycorrhizal fungi, with conservation efforts aiming to protect networks.
– Ongoing research explores interactions, advancements in molecular techniques, and potential biotechnological applications.
– Climate change implications on mycorrhizal fungi, modeling network dynamics, and predicting responses to disturbances.

Mycorrhiza (Wikipedia)

A mycorrhiza (from Greek μύκης mýkēs, "fungus", and ῥίζα rhiza, "root"; pl.: mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, its root system. Mycorrhizae play important roles in plant nutrition, soil biology, and soil chemistry.

Many conspicuous fungi such as the fly agaric (upper left) form ectomycorrhiza (upper right) with tree rootlets. Arbuscular mycorrhiza (lower left) are very common in plants, including crop species such as wheat (lower right)

In a mycorrhizal association, the fungus colonizes the host plant's root tissues, either intracellularly as in arbuscular mycorrhizal fungi, or extracellularly as in ectomycorrhizal fungi. The association is normally mutualistic. In particular species, or in particular circumstances, mycorrhizae may have a parasitic association with host plants.