The role of the GRAS protein RAM1 in arbuscule development and function.

The arbuscular mycorrhiza (AM) symbiosis between most land plants and glomeromycotan fungi increases plant mineral nutrition and therefore has great potential for sustainable agriculture. At the heart of the symbiosis are highly branched fungal structures called arbuscules, which transfer nutrients into the host cell. During arbuscule development the host cell rearranges and determines arbuscule growth. We identified the GRAS transcription factor gene REDUCED ARBUSCULAR MYCORRHIZA 1 (RAM1) as a regulator of arbuscule development and propose here to study the regulation and function of this important protein.