John T. Sullivan

TL;DR: The chromosomal symbiotic element of M. loti strain ICMP3153 is transmissible in laboratory matings to at least three genomic species of nonsymbiotic mesorhizobia and is termed a symbiosis island on the basis of its many similarities to pathogenicity islands.

TL;DR: It is shown that host-encoded mechanisms control three alternative entry processes operating in the epidermis, the root cortex and at the single cell level, which provides support for the origin of rhizobial infection through direct intercellular epidermal invasion and subsequent evolution of crack entry and root hair invasions observed in most extant legumes.

TL;DR: The results suggest that the diverse strains arose by transfer of chromosomal symbiotic genes from ICMP3153 to nonsymbiotic rhizobia in the environment.

TL;DR: The nucleotide sequence of the R7A island is determined and its deduced genetic complement is compared with that reported for the 611-kb putative symbiosis island of M. loti strain MAFF303099, indicating that the island lacks plasmid replication genes, suggesting that it is a site-specific conjugative transposon.

TL;DR: The results suggest that ligand recognition through direct ligand binding is a key step in the receptor-mediated activation mechanism leading to root nodule development in legumes.