Glomeromycotina

Glomeromycotina is a division of fungi that forms arbuscular mycorrhizae. These fungi are obligate biotrophs, meaning they can only survive by forming a symbiotic relationship with plant roots. The symbiotic association, known as arbuscular mycorrhiza, is characterized by the formation of branched structures called arbuscules within the root cells of the host plant. These arbuscules are the primary sites of nutrient exchange between the fungus and the plant. The fungus receives carbohydrates from the plant, while the plant benefits from increased uptake of phosphorus and other essential nutrients from the soil.

Glomeromycotina fungi are found in virtually all terrestrial ecosystems, playing a crucial role in plant nutrient acquisition and soil health. They are essential for the growth of a vast majority of land plants, including many agricultural crops. The spores of these fungi are typically large, ranging from 20 to 200 micrometers in diameter, and are often found in soil. Reproduction in Glomeromycotina is primarily asexual, with spores produced by mitosis.

The classification of Glomeromycotina has undergone significant changes with the advent of molecular phylogenetic studies. Previously considered part of the Zygomycota, they are now recognized as a distinct phylum, Glomeromycota. This phylum contains a single class, Glomeromycetes, and several orders, including Glomerales, Archaeosporales, and Diversisporales. Despite their ecological importance, very few species within Glomeromycotina have been successfully cultured in vitro, which has historically limited research on their physiology and genetics. Their widespread distribution and symbiotic dependence on plants highlight their fundamental role in terrestrial ecosystems.