How plants deal with beneficial and pathogenic microorganisms how they can tolerate ones face pathogens at the same time are questions that remain puzzling to plant biologists. Legume good models explore those issues, as their interactions nitrogen-fixing bacteria called rhizobia results in a drastic easy-to-follow phenotype of nodulation. Intriguingly, despite massive chronic infection, legume...

Ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease, which colonizes susceptible Medicago truncatula via the intact root tip. Infection involves four steps: appearance of root tip symptoms, root tip cortical cell invasion, vessel colonization, and foliar wilting. We examined this pathosystem by in vitro inoculation of intact roots of susceptible or resistant M. ...

The phytopathogenic bacterium Ralstonia solanacearum encodes a family of seven type III secretion system (T3SS) effectors that contain both a leucine-rich repeat and an F-box domain. This structure is reminiscent of a class of typical eukaryotic proteins called F-box proteins. The latter, together with Skp1 and Cullin1 subunits, constitute the SCF-type E3 ubiquitin ligase complex and control sp...

In tobacco (Nicotiana tabacum), Ralstonia solanacearum OE1-1 (RsOE1-1) is pathogenic, whereas R. solanacearum 8107 (Rs8107) is nonpathogenic and induces the hypersensitive response (HR). To elucidate the molecular mechanisms of plant-R. solanacearum interactions, we used differential display to isolate a cDNA fragment, A6, regulated in tobacco by inoculation with RsOE1-1. The deduced amino acid...

RsRGA4 (for Ralstonia solanacearum-responsive gene A4) encodes a polypeptide similar to S-locus glycoprotein (SGP) from Brassica rapa and SGP-like proteins from Ipomoea trifida and Medicago truncatula. Therefore, we designated RsRGA4 as NtSGLP (for Nicotiana tabacum SGP-like protein) and NbSGLP (its Nicotiana benthamiana ortholog). NbSGLP is expressed in root, leaf, petal, gynoecium, and stamen...

This chapter synthesizes our current knowledge on the ecological genetics of the model legume Medicago truncatula. After a short introduction to the life cycle of the species, we describe the mating system of M truncatula and how selfing rates in nature can be inferred both by progeny testing and population surveys. We then review what is currently known on the distribution of genetic diversity...

Ralstonia solanacearum strain FQY_4 was isolated from a bacterial wilt nursery, which is used for breeding crops for Ralstonia resistance in China. Here, we report the complete genome sequence of FQY_4 and its comparison with other published R. solanacearum genomes, especially with the strains GMI1000 and Y45 in the same group.