Response of the symbiont Ensifer meliloti to the plant flavonoid lutelin: not only symbiosis.

The present work was mainly addressed to provide an extensive phenotypic investigation of the luteolin effects on the phenotypes of E. meliloti to get an interpretative framework in modeling luteolin-induced metabolic switches. In the context of the luteolin-responsive phenotypes, the changes dependent or independent from the NodD regulation (i.e the major luteolin sensor) were elucidated using a deletion nodD mutant of E. meliloti and the possible contribution of other luteolin mediators, beyond NodD, was then investigated.