mykorhyyssymbioosi

Mykorrhiza, derived from the Greek words "mykes" (fungus) and "rhiza" (root), refers to a symbiotic association between fungi and plant roots. This mutually beneficial relationship is widespread in terrestrial ecosystems, with an estimated 90% of plant species forming such partnerships. The fungus colonizes the plant's root system, either externally or by penetrating the root tissues. In return for carbohydrates produced by the plant through photosynthesis, the fungus provides the plant with essential nutrients and water absorbed from the soil.

Fungal hyphae, which are microscopic, thread-like structures, vastly increase the surface area available for nutrient and water uptake compared to the plant's roots alone. This enhanced absorption is particularly beneficial for immobile nutrients like phosphorus and nitrogen, which are often scarce in the soil. The fungus can also help protect the plant from pathogens and improve its tolerance to environmental stresses such as drought and heavy metal toxicity.

There are two main types of mykorrhiza. Ectomykorrhiza, predominantly found with trees like pines and oaks, forms a sheath around the root tips and grows between root cells but does not penetrate them. Endomykorrhiza, also known as arbuscular mykorrhiza (AM), is more common and involves the fungus penetrating the root cells, forming branched structures called arbuscules where nutrient exchange occurs. This ancient symbiosis plays a critical role in plant health and ecosystem functioning.