Auxin-mediated regulation of arbuscular mycorrhizal symbiosis: A role of SlGH3.4 in tomato.

Most land plants can establish symbiosis with arbuscular mycorrhizal (AM) fungi to increase fitness to environmental challenges. The development of AM symbiosis is controlled by intricate procedures involving all phytohormones. However, the mechanisms underlying the auxin-mediated regulation of AM symbiosis remains largely unknown.

A mycorrhiza-specific H -ATPase is essential for arbuscule development and symbiotic phosphate and nitrogen uptake.

Most land plants can form symbiosis with arbuscular mycorrhizal (AM) fungi to enhance uptake of mineral nutrients, particularly phosphate (Pi) and nitrogen (N), from the soil. It is established that transport of Pi from interfacial apoplast into plant cells depends on the H gradient generated by the H -ATPase located on the periarbuscular membrane (PAM); however, little evidence regarding the potential link between mycorrhizal N transport and H -ATPase activity is available to date. Here, we report that a PAM-localized tomato H -ATPase, SlHA8, is indispensable for arbuscule development and mycorrhizal P and N uptake.