Arbuscular mycorrhiza is one of the most common type of mycorrhiza in plant kingdom. Process of plant root colonization by arbuscular mycorrhizal fungi is consisted of four phases: presymbiotic phase, phase of contact and hyphae penetration to the roots, growth phase of hyphae inside the roots and phase of mycorrhizal intracellular structure development. The formation of symbiosis between fungi and host plant requires the exchange of molecular signals between these organisms. Plant signal molecules are described as strigolactones and cutin monomers whereas fungal signal molecules are lipo-chito-oligo-saccharides and short chito-oligosaccharides. During the contact with plant roots fungal hyphae form appresorium on the surface of epidermis. After appresorium creation, the pre-penetration apparatus (PPA) is formed in plant cell, which is a structure defining a route of the hyphae overgrowing across the plant cell. Afterwards the fungus penetrates the epidermal cell and the cell of root cortex, where hyphae leave the cell and enter into appoplast, growing and branching along the root axis.

73-78