Obligatory Reduction of Ferric Chelates in Iron Uptake by Soybeans

Chaney, Rufus L.; Brown, J. C.; Tiffin, L. O.

doi:10.1104/pp.50.2.208

Cited by 652 publications

(335 citation statements)

References 19 publications

Supporting

Mentioning

311

Contrasting

Unclassified

Order By: Relevance

“…Plants have evolved different uptake systems for iron (Takagi et al, 1984;Marschner et al, 1986;Römheld, 1987). The dicotyledons may increase iron availability in the rhizosphere by proton excretion (Römheld et al, 1984) and the release of reductants (Chaney et al, 1972). In contrast, the Gramineae release phytosiderophores (Takagi et al, 1984).…”

Section: Discussionmentioning

confidence: 99%

**The global regulator GacA of Pseudomonas fluorescens CHA0 is required for suppression of root diseases in dicotyledons but not in Gramineae**

1997

View full text Add to dashboard Cite

Pseudomonas fluorescens strain CHA0 suppresses various plant diseases caused by soil‐borne fungi. The pseudomonad produces the antimicrobial metabolites 2,4‐diacetylphloroglucinol (Phl), pyoluteorin (Plt) and hydrogen cyanide, which are important for disease suppression, as well as the siderophores pyoverdine (Pvd), salicylic acid (Sal) and pyochelin (Pch). In the current work, a derivative of CHA0 with a mutation in the global regulator gene gacA (GacA−), which is unable to produce Phl, Plt and HCN, failed to protect the dicotyledonous plants cress and cucumber against damping‐off caused by Pythium ultimum. In contrast, the GacA− mutant could still protect the Gramineae wheat and maize against damping‐off mediated by the same strain of P. ultimum, and wheat against take‐all caused by Gaeumannomyces graminis. However, the GacA− mutant overproduced Pch and Pvd. To gain more insight into disease protection afforded by the GacA− mutant, a GacA− Pvd− double mutant (strain CHA496) was constructed by gene replacement. Strain CHA496 overproduced Pch and Sal compared with CHA0 and protected wheat against P. ultimum and G. graminis, whereas cress and cucumber were not protected. Addition of FeCl3 repressed Pch and Sal production by strain CHA496 in vitro and impaired the protection of wheat in soil microcosms. In conclusion, a functional gacA gene was necessary for the protection of dicotyledons against root diseases, but not for that of Gramineae. Results indicated also that Pch and/or Sal were involved in the ability of the GacA− Pvd− mutant of CHA0 to suppress root diseases in Gramineae.

show abstract

Section: Discussionmentioning

confidence: 99%

**The global regulator GacA of Pseudomonas fluorescens CHA0 is required for suppression of root diseases in dicotyledons but not in Gramineae**

1997

View full text Add to dashboard Cite

show abstract

“…The results also show that 50% or more of the Fe in litter leachate is in the reduced form (Fe(II)). Reduced Fe is the bioavailable form of Fe taken up by plants; ferric compounds are reduced prior to assimilation (Chaney et al 1972). Consequently, it is not surprising to find large amounts of ferrous iron in vegetation.…”

Section: Relation Of Iron Chemistry To Dissolved Organic Carbon and Phmentioning

confidence: 99%

Dynamics of oxidized and reduced iron in a northern hardwood forest

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The demonstration of Fe3+ reduction at the root surface [29,31] resulted in the proposal that a 'ferric ion reductase' is an intimate component of iron assimilation in plants.…”

Section: Plant Iron Assimilation Modelsmentioning

confidence: 99%