INDOLE-3-ACETIC-ACID BIOSYNTHESIS BY XANTHOMONAS-AXONOPODIS PV. CITRIIS INCREASED IN THE PRESENCE OF PLANT LEAF EXTRACTS

Indole-3-acetic acid production by Xanthomonas strains pathogenic to c itrus was analyzed by reversed-phase highperformance liquid chromatogr aphy, thin-layer chromatography, UV spectroscopy and gas chromatograph y-mass spectrometry, and quantified by high-performance liquid chromat ography with fluorescence detection. Amounts of auxin produced by Xant homonas strains were low when compared with indole-3-acetic acid biosy nthesis by other bacteria. In three different experiments it was shown that the addition of plant leaf extracts to bacterial cultures increa sed indole-3-acetic acid biosynthesis by Xanthomonas axonopodis pv. ci tri 223. (C) 1998 Federation of European Microbiological Societies. Pu blished by Elsevier Science B.V.