Mykorrhizala

Mykorrhizala, or mycorrhizal association, refers to mutually beneficial symbioses between soil fungi and the roots of most land plants. In this relationship, fungal hyphae colonize the root system and extend the plant's effective root surface area, while the fungus receives carbohydrates produced by the plant through photosynthesis.

The exchange includes nutrients such as phosphorus, nitrogen, and micronutrients, and improved water uptake, contributing to plant growth and drought tolerance. Fungal hyphae can also help stabilize soil structure through hyphal networks and contribute to pathogen resistance by occupying root space and producing protective compounds.

Major forms include arbuscular mycorrhiza (AM), in which fungal hyphae enter root cortical cells and form arbuscules; vesicles can act as storage; AM is widespread in most herbaceous plants and many crops. Ectomycorrhiza (EM) form a sheath around the root and a network between outer root cells called the Hartig net, common in many trees and woody plants. Other specialized forms occur in ericoid and orchid mycorrhizas.

Ecological and agricultural significance: nearly all terrestrial plants form mycorrhizal associations; they influence nutrient cycling, soil health, and ecosystem productivity. In agriculture, inoculation with mycorrhizal fungi can improve nutrient uptake and reduce fertilizer inputs, though effectiveness depends on soil conditions, plant species, and fungal compatibility.