Iron Acquisition from Fe-Pyoverdine by Arabidopsis thaliana

Abstract

Taking into account the strong iron competition in the rhizosphere and the high affinity of pyoverdines for Fe(III), these molecules are expected to interfere with the iron nutrition of plants, as they do with rhizospheric microbes. The impact of Fe-pyoverdine on iron content of Arabidopsis thaliana was compared with that of Fe-EDTA. Iron chelated to pyoverdine was incorporated in a more efficient way than when chelated to EDTA, leading to increased plant growth of the wild type. A transgenic line of A. thaliana overexpressing ferritin showed a higher iron content than the wild type when supplemented with Fe-EDTA but a lower iron content when supplemented with Fe-pyoverdine despite its increased reductase activity, suggesting that this activity was not involved in the iron uptake from pyoverdine. A mutant knock-out iron transporter IRT1 showed lower iron and chlorophyll contents when supplemented with Fe-EDTA than the wild type but not when supplemented with Fe-pyoverdine, indicating that, in contrast to iron from EDTA, iron from pyoverdine was not incorporated through the IRT1 transporter. Altogether these data suggest that iron from Fe-pyoverdine was not incorporated in planta through the strategy I, which is based on reductase activity and IRT1 transporter. This is supported by the presence of pyoverdine in planta as shown by enzyme-linked immunosorbent assay and by tracing 15N of 15N-pyoverdine.

Characterization of Siderophore Producing Rhizobacteria and Its Effect on Growth Performance of Different Vegetables

“…Siderophore produced by rhizosphericbacteria improve rhizosphere colonization and play an important role in iron mineralization &supplement to plant (Vansuyt et al, 2007). Moreover it also play important antagonistic role against phytopathogens (Chincholkar et al, 2007b).…”

Review on iron availability in soil: interaction of Fe minerals, plants, and microbes

“…In any case, strategy II plants are able to use, although to a low extent, Fe from Fe III -MS s complexes via, at least in part, indirect mechanisms (Duijff et al 1994;Robin et al 2008). Also for plants belonging to strategy I (dicots), an impact of Fe III -MS s on the micronutrient nutrition has been assessed (see also Lemanceau et al 2009), with the hypothesis of the involvement of a putative transporter different than IRT1 for the uptake of the integral Fe III -MS s complex (Vansuyt et al 2007). On the other hand, plant-derived Fe-PS S or Fe-organic acids (like Fe citrate) complexes can be a good source of nutrient (Fe) and energy (via PS s and organic compound degradation), inducing the microbes to depress the release of their own MS s and taking advantage of the Fe mobilized by these plant chelators (Marschner and Crowley 1998;Von Wiren et al 1993;Jones 1998).…”

Siderophoregenic Acinetobacter calcoaceticus isolated from wheat rhizosphere with strong PGPR activity

“…Siderophoregenic strains have ability to mediate plant growth promotion directly as well as indirectly. Iron-siderophore complex is accepted by plants to quench iron thirst in soil, a direct mechanism, (Sharma and Johri, 2003;Vansuyt et al, 2007) moreover chelation of soluble iron by microbial siderophores leads to growth inhibition of phytopathogen (Bano and Musarrat, 2003).…”

“…Lost ability to synthesize siderophores lead to loss of ability to synthesize cyanide and thus marred biocontrol abilities of strain proves physiological importance of iron (Voisard et al, 1989). Siderophores produced by rhizosphere inhabitants has been studied well and it has been reported that ability to produce siderophores not only improve rhizosphere colonization of producer strain but also play an important role in iron nutrition of plant (Vansuyt et al, 2007) and antagonism against phytopathogens (Chincholkar et al, 2007b). Role of siderophores in induced systemic resistance (ISR) in plants was also well appreciated (De Meyer et al, 1999).…”