mykoryza

Mycorrhiza, a term derived from the Greek words for fungus (mykes) and root (rhiza), describes a symbiotic association between fungi and the roots of plants. This mutualistic relationship is widespread, occurring in the vast majority of terrestrial plant species. The fungus colonizes the plant's root system, either externally or internally, and in exchange for carbohydrates produced by the plant through photosynthesis, the fungus provides the plant with essential nutrients, particularly phosphorus and nitrogen, which are often scarce in the soil.

There are several types of mycorrhizae, with the two most common being ectomycorrhizae and endomycorrhizae. Ectomycorrhizae typically form a sheath around the plant root tips and penetrate the spaces between root cells, but not into the cells themselves. This type is prevalent in forest trees like pines and oaks. Endomycorrhizae, also known as arbuscular mycorrhizae (AM), penetrate the cell walls of the root cortex, forming specialized structures called arbuscules within the cells where nutrient exchange occurs. AM associations are found in a much broader range of plants, including most agricultural crops, grasses, and herbaceous plants.

The benefits of mycorrhizal associations extend beyond nutrient acquisition. Mycorrhizal fungi can also enhance plant water uptake, improve tolerance to soil salinity and heavy metals, and increase resistance to root pathogens. Furthermore, the fungal hyphae expand the effective root surface area, allowing plants to access nutrients and water from a larger volume of soil. This intricate partnership plays a crucial role in plant health, ecosystem function, and the overall productivity of terrestrial environments.