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Updated: May 22, 2026

Synthesis of Indoxyl-glycosides for Detection of Glycosidase Activities
Published on: May 27, 2015
Biosynthesis of the halogenated auxin, 4-chloroindole-3-acetic acid
Nathan D Tivendale1, Sandra E Davidson, Noel W Davies
1School of Plant Science , University of Tasmania, Sandy Bay, Tasmania, Australia 7005.
Abstract:
Seeds of several agriculturally important legumes are rich sources of the only halogenated plant hormone, 4-chloroindole-3-acetic acid. However, the biosynthesis of this auxin is poorly understood. Here, we show that in pea (Pisum sativum) seeds, 4-chloroindole-3-acetic acid is synthesized via the novel intermediate 4-chloroindole-3-pyruvic acid, which is produced from 4-chlorotryptophan by two aminotransferases, TRYPTOPHAN AMINOTRANSFERASE RELATED1 and TRYPTOPHAN AMINOTRANSFERASE RELATED2. We characterize a tar2 mutant, obtained by Targeting Induced Local Lesions in Genomes, the seeds of which contain dramatically reduced 4-chloroindole-3-acetic acid levels as they mature. We also show that the widespread auxin, indole-3-acetic acid, is synthesized by a parallel pathway in pea.
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