Arbuscular mycorrhizal fungi (AMF) are soil fungi, obligate biotrophic fungi and form the most common mutualistic symbiosis in nature: the arbuscular mycorrhiza (AM). This association occurs on the roots of most plants, promoting improvements in plant growth and development and increasing tolerance and/or plant resistance to several adverse environmental agents. In addition, AMF can be a potential biological control agent of plant diseases. These fungi produce glomalin, a protein that plays a key role in soil stability and in the biostabilization of contaminated soils. The different responses of plants to this symbiosis can be assigned to the functional diversity of AM, depending of the interaction between AMF, plants and environmental conditions. The establishment and functioning of AMs under stress conditions involves a complex process of recognition and development, accompanied by physiological, biochemical and molecular changes in both symbionts. In addition, the mycorrhizal colonization of roots has a significant impact on the gene expression of several plants that encode proteins presumably involved in stress tolerance. In this context, since the AMF are essential for the establishment and adaptation of plants on disturbed sites, this review covers the molecular and physiological mechanisms of the AM association, responsible for this adaptation and greater stress tolerance of plants.
arbuscular mycorrhizal fungi; signaling; functional diversity; glomalin