Endogenous indoles and the biosynthesis and metabolism of indole-3-acetic acid in cultures ofRhizobium phaseoli

✍ Scribed by A. Ernstsen; G. Sandberg; A. Crozier; C. T. Wheeler

• Publisher: Springer-Verlag
• Year: 1987
• Tongue: English
• Weight: 680 KB
• Volume: 171
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00398689

✦ Synopsis

Gas chromatography-mass spectrometric analyses of purified extracts from cultures of Rhizobium phaseoli wild-type strain 8002, grown in a non-tryptophan-supplemented liquid medium, demonstrated the presence of indole-3-acetic acid (IAA), indole-3-ethanol (IEt), indole-3-aldehyde and indole-3-methanol (IM). In metabolism studies with (3)H-, (14)C- and (2)H-labelled substrates the bacterium was shown to convert tryptophan to IEt, IAA and IM; IEt to IAA and IM; and IAA to IM. Indole-3-acetamide (IAAm) could not be detected as either an endogenous constituent or a metabolite of [(3)H]tryptophan nor did cultures convert [(14)C]IAAm to IAA. Biosynthesis of IAA in R. phaseoli, thus, involves a different pathway from that operating in Pseudomonas savastanio and Agrobacterium tumefaciens-induced crown-gall tumours.