Application of capillary liquid chromatography — electrospray mass spectrometry to identify major siderophores of Erwinia amylovora as proferrioxamines and their potential role in virulence

摘要: A large number of hydroxamate siderophores Erwinia amylovora have been identified using capillary liquid chromatography — electrospray mass spectrometry in combination with ferric ion complexation studies. Specifically, we the trihydroxamate siderophores, proferrioxamines E, D2, X1 X2, and novel X7, corresponding open chain G1, G2a G2b, G1t (a truncated G1), tetrahydroxamate T1-T3, as well a partially characterized siderophore T4. Production was achieved minimal medium iron concentrations equal to or less than 10-6 M. No qualitative differences pattern were found between E. strains from different parts world dihydrophenylalanine-producing -non-producing strains. Proferrioxamines may be important virulence factors proferrioxamine biosynthesis offer targets for new fire blight control agents. Before launching program develop specific inhibitors biosynthesis, it is desirable confirm that mutants solely defective are indeed avirulent. Sneath et al. previously reported on Ea321T140, Ea321T145, Ea321T160 avirulent siderophore-deficient could partly complemented by cosmid pCPP610 [Acta Horticult. 273, 255 (1990)]. It not conclusively shown, however, avirulence result blocked mutations regulatory genes deficiencies merely being pleiotropic effects. According our spectrometric analysis, only has clear deficiency can reversed complementation pCPP610. Ea321T140 still capable expressing amounts proferrioxamines, whereas does restore production Ea321T145. Traces also Ea321T145 Ea321T160. These results suggest that, other thought, affected rather biosynthetic contain all necessary production. The question whether controlled via interference thus remains open.