Recognition and infection process, basis for host specificity of arbuscular mycorrhizal fungi

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs, which derive nutrients from living cells of host plants (Lewis, 1973). The process of infection of host roots is characterized by distinct stages involving a number of complex morphogenetic changes in the fungi: spore germination, hyphal differentiation, appressorium formation, root penetration, intercellular growth and arbuscule formation.