Cloning and Biochemical Characterization of ToFZY, a Tomato Gene Encoding a Flavin Monooxygenase Involved in a Tryptophan-dependent Auxin Biosynthesis Pathway

Expósito-Rodríguez, Marino; Borges, Andrés A.; Borges-Pérez, Andrés; Hernández, Marita; Pérez, Jose Antonio Pérez

doi:10.1007/s00344-007-9019-2

Cited by 65 publications

(55 citation statements)

References 32 publications

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“…Initially, it was proposed based on in vitro assays that YUCs catalyze the N-hydroxylation of tryptamine (Zhao et al, 2001;Expósito-Rodríguez et al, 2007, Kim et al, 2007LeCLere et al, 2010). However, the early biochemical work had several caveats.…”

Section: The Biochemical Mechanisms Of Yuc Flavin Monooxygenasesmentioning

confidence: 99%

“…The YUC proteins purified from E. coli were probably not folded correctly. Early enzyme assays of YUC proteins were all qualitative and only tryptamine was tested as a substrate (Zhao et al, 2001;Expósito-Rodríguez et al, 2007, Kim et al, 2007LeCLere et al, 2010). In addition, the early enzymatic assays required the addition of free FAD to the reaction mixture, probably causing off-enzyme reactions.…”

Section: The Biochemical Mechanisms Of Yuc Flavin Monooxygenasesmentioning

confidence: 99%

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Auxin Biosynthesis

Zhao

2014

The Arabidopsis Book

188

171

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Indole-3-acetic acid (IAA), the most important natural auxin in plants, is mainly synthesized from the amino acid tryptophan (Trp). Recent genetic and biochemical studies in Arabidopsis have unambiguously established the first complete Trp-dependent auxin biosynthesis pathway. The first chemical step of auxin biosynthesis is the removal of the amino group from Trp by the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) family of transaminases to generate indole-3-pyruvate (IPA). IPA then undergoes oxidative decarboxylation catalyzed by the YUCCA (YUC) family of flavin monooxygenases to produce IAA. This two-step auxin biosynthesis pathway is highly conserved throughout the plant kingdom and is essential for almost all of the major developmental processes. The successful elucidation of a complete auxin biosynthesis pathway provides the necessary tools for effectively modulating auxin concentrations in plants with temporal and spatial precision. The progress in auxin biosynthesis also lays a foundation for understanding polar auxin transport and for dissecting auxin signaling mechanisms during plant development.

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Section: The Biochemical Mechanisms Of Yuc Flavin Monooxygenasesmentioning

confidence: 99%

Section: The Biochemical Mechanisms Of Yuc Flavin Monooxygenasesmentioning

confidence: 99%

Auxin Biosynthesis

Zhao

2014

The Arabidopsis Book

188

171

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“…Until recently, it was thought that the enzymes involved in converting Trp to IPyA, the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) family (Stepanova et al, 2008;Tao et al, 2008), acted in a separate pathway from the YUCCA (YUC) family (Zhao et al, 2001;Zhao, 2010). The YUCs were originally thought to function in the tryptamine pathway, converting tryptamine to N-hydroxytryptamine (Zhao et al, 2001;Expósito-Rodríguez et al, 2007;LeClere et al, 2010). However, the original biochemical function of the YUCs was called into question (Tivendale et al, 2010), and it has now been reported that YUCs act downstream of the TAA family, converting IPyA to IAA Stepanova et al, 2011;Won et al, 2011;Kriechbaumer et al, 2012).…”

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confidence: 99%

Biosynthesis of the Halogenated Auxin, 4-Chloroindole-3-Acetic Acid

et al. 2012

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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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“…We can be confident that PsTAR2 is a key auxin synthesis gene at the late stages of seed development, required to maintain normal levels of 4-Cl-IAA, the predominant auxin at that stage. 1,[14][15][16]24 Pisum sativum, 3,5,25 Solanum lycopersicum, 9,26 Zea mays, 27,28 and petunia. 29 the direct metabolites of trp, and some proposed enzymes, are indicated plants.…”

Section: A Mutation Affecting the Synthesis Of 4-chloroindole-3-acetimentioning

confidence: 99%

A mutation affecting the synthesis of 4-chloroindole-3-acetic acid

Ross

Tivendale

Davidson

et al. 2012

Plant Signaling & Behavior

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Evidence for the IPyA pathway in pea seeds comes from metabolism experiments with labeled compounds, the isolation of genes, and the effects of a mutation in one of those genes.2 Pea seeds are an excellent system for studying the metabolism of potential auxin intermediates. They are large, and labeled compounds can be injected into the seeds either in situ or after they are excised and placed in vitro. Typically, potential intermediates are injected at the liquid endosperm stage, and their subsequent metabolism determined by mass spectrometry. Additional compounds are injected into separate seeds as controls. For example, to test whether the tryptamine pathway operates in pea seeds, (see Fig. 1) labeled tryptamine was injected. Labeled tryptophan was injected into separate control seeds.3 Label was detected in IAA in the latter but not the former case, indicating that tryptamine is not an intermediate between tryptophan and IAA in this system. The lack of conversion of tryptamine to IAA cannot be attributed to wounding caused by the injection, because tryptophan was converted to IAA. Metabolism experiments also ruled out the indole-3-acetamide pathway (see Fig. 1), 2 while a fourth tryptophan-dependent pathway, via indole-3-acetaldoxime (see Fig. 1), is thought not to operate outside the Brassicaceae. When it became clear that the tryptamine pathway does not operate in pea seeds 3 (although it can operate in roots 5 ), we decided to investigate the IPyA pathway. We cloned three aminotransferase genes from pea and showed that two of the encoded enzymes convert tryptophan to IPyA, which is then converted in some way to IAA.2 In pea seeds IAA is the most abundant auxin traditionally, schemes depicting auxin biosynthesis in plants have been notoriously complex. they have involved up to four possible pathways by which the amino acid tryptophan might be converted to the main active auxin, indole-3-acetic acid (iaa), while another pathway was suggested to bypass tryptophan altogether. it was also postulated that different plants use different pathways, further adding to the complexity. in 2011, however, it was suggested that one of the four tryptophan-dependent pathways, via indole-3-pyruvic acid (iPya), is the main pathway in Arabidopsis thaliana, 1 although concurrent operation of one or more other pathways has not been excluded. We recently showed that, for seeds of Pisum sativum (pea), it is possible to go one step further.2 our new evidence indicates that the iPya pathway is the only tryptophan-dependent iaa synthesis pathway operating in pea seeds. We also demonstrated that the main auxin in developing pea seeds, 4-chloroindole-3-acetic acid (4-Cl-iaa), which accumulates to levels far exceeding those of iaa, is synthesized via a chlorinated version of the iPya pathway.

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Cloning and Biochemical Characterization of ToFZY, a Tomato Gene Encoding a Flavin Monooxygenase Involved in a Tryptophan-dependent Auxin Biosynthesis Pathway

Cited by 65 publications

References 32 publications

Auxin Biosynthesis

Auxin Biosynthesis

Biosynthesis of the Halogenated Auxin, 4-Chloroindole-3-Acetic Acid

A mutation affecting the synthesis of 4-chloroindole-3-acetic acid

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