ISSN:
1572-8773
Keywords:
Siderophore identification
;
Ferrirhodin
;
Botrytis cinerea
;
NMR studies
;
Transport
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary The plant pathogenic hyphomyceteBotrytis cinerea has been shown to produce several trihydroxamate siderophores under conditions of low-iron stress. The total siderophores amounted to approximately 30 mg/l culture filtrate after 5 days of incubation in an asparagine/salt/glucose medium. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) on a reversed phase indicated that ferrirhodin is the predominant siderophore of this fungus. Chemical characterization of the principal siderophore by fast-atom-bombardment (FAB) mass spectrometry, nuclear magnetic resonance (1H-NMR,13C-NMR) and comparison with a reference revealed the identity with ferrirhodin. NMR studies performed on desferrirhodin (desferrirhodin) in dimethylsulfoxide and water revealed the existence of two conformers in D2O resulting from acis-trans isomerization of the hydroxamic acid groups. Comparative iron-uptake studies showed the following order of uptake inB. cinerea: ferrichrysin (100%), ferrirubin (57%), ferrirhodin (45%), hexahydroferrirhodin (45%), coprogen 6%. Concentration-dependent uptake of ferrirhodin resulted in saturation kinetics only in the low concentration range of 0–30 μM (K m = 2.5 μM,V max = 80 pmol min−1 mg(−1). A non-saturable, linear uptake was observed in the high concentration range of 30–80 μM. The low concentration range appears to be the physiologically significant range, where siderophore-mediated iron transport inB. cinerea occurs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01138066
