The biosynthesis of the main auxin in plants (indole-3-acetic acid [IAA]) has been elucidated recently and is thought to involve the sequential conversion of Trp to indole-3-pyruvic acid to IAA. However, the pathway leading to a less well studied auxin, phenylacetic acid (PAA), remains unclear. Here, we present evidence from metabolism experiments that PAA is synthesized from the amino acid Phe, via phenylpyruvate. In pea (Pisum sativum), the reverse reaction, phenylpyruvate to Phe, is also demonstrated. However, despite similarities between the pathways leading to IAA and PAA, evidence from mutants in pea and maize (Zea mays) indicate that IAA biosynthetic enzymes are not the main enzymes for PAA biosynthesis. Instead, we identified a putative aromatic aminotransferase (PsArAT) from pea that may function in the PAA synthesis pathway.

Item Type:	Refereed Article
Keywords:	auxin, biosynthesis, amino acids
Research Division:	Biological Sciences
Research Group:	Plant biology
Research Field:	Plant physiology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Grains and seeds
Objective Field:	Rice
UTAS Author:	Cook, SD (Mr Sam Cook)
UTAS Author:	Nichols, DS (Dr David Nichols)
UTAS Author:	Smith, J (Associate Professor Jason Smith)
UTAS Author:	McAdam, EL (Dr Erin McAdam)
UTAS Author:	Quittenden, L (Dr Laura Quittenden)
UTAS Author:	Ross, JJ (Associate Professor John Ross)
ID Code:	109435
Year Published:	2016
Funding Support:	Australian Research Council (DP130103357)
Web of Science® Times Cited:	23
Deposited By:	Plant Science
Deposited On:	2016-06-16
Last Modified:	2017-11-02
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