The role of diffusible signals in the establishment of rhizobial and mycorrhizal symbioses.- Infection of Lotus japonicus roots by Mesorhizobium loti.-Signalling and re-structuring of the plant cell architecture in AM symbiosis.- Common pathways in legume and arbuscular mycorrhizal symbioses.- Signalling and communication in the actinorhizal symbioses.- Signalling in the cyanobacterial-plant symbioses.- Signalling in ectomycorrhizal...