Pyoverdines are siderophores synthesized by fluorescent pseudomonas spp. Under iron-limiting conditions, these high-affinity ferric iron chelators are excreted by bacteria in the soil to acquire iron. Pyoverdines produced by beneficial Pseudomonas ameliorate plant growth. Here, we investigate the physiological incidence and mode of action of pyoverdine from P. fluorescens C7R12 on Arabidopsis thaliana plants grown under iron-sufficient or -deficient conditions. Pyoverdine was provided to the medium in its iron free structure (apo-pyoverdine), thus mimicking a situation in which it is produced by bacteria. Remarkably, apo-pyoverdine abolished the iron deficiency phenotype and restored the growth of plants maintained in the iron-deprived medium. In contrast to a P. fluorescens C7R12 strain impaired in apo-pyoverdine production, the wild-type C7R12 reduced the accumulation of anthocyanins in plants grown in iron-deficient conditions. A microarray analysis showed that under this condition, apo-pyoverdine modulated the expression of around 2000 genes. Notably, apo-pyoverdine positively regulated the expression of genes related to development and iron acquisition/redistribution while it repressed the expression of defense-related genes. Accordingly, the growth promoting effect of apo-pyoverdine in plants grown under iron-deficient conditions was impaired in irt1 and fro2 knock-out mutants and was prioritized over immunity as highlighted by an increased susceptibility to the pathogen Botrytis cinerea. This process was accompanied by an over-expression of the transcription factor HBI1, a key node for the cross-talk between growth and immunity. This study reveals an unprecedented mode of action of pyoverdine in Arabidopsis and demonstrates that its incidence on physiological traits depends on the plant iron status.