Document Detail


Conversion of tryptophan to indole-3-acetic acid by TRYPTOPHAN AMINOTRANSFERASES OF ARABIDOPSIS and YUCCAs in Arabidopsis.
MedLine Citation:
PMID:  22025721     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Auxin is an essential hormone, but its biosynthetic routes in plants have not been fully defined. In this paper, we show that the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) family of amino transferases converts tryptophan to indole-3-pyruvate (IPA) and that the YUCCA (YUC) family of flavin monooxygenases participates in converting IPA to indole-3-acetic acid, the main auxin in plants. Both the YUCs and the TAAs have been shown to play essential roles in auxin biosynthesis, but it has been suggested that they participate in two independent pathways. Here, we show that all of the taa mutant phenotypes, including defects in shade avoidance, root resistance to ethylene and N-1-naphthylphthalamic acid (NPA), are phenocopied by inactivating YUC genes. On the other hand, we show that the taa mutants in several known auxin mutant backgrounds, including pid and npy1, mimic all of the well-characterized developmental defects caused by combining yuc mutants with the auxin mutants. Furthermore, we show that overexpression of YUC1 partially suppresses the shade avoidance defects of taa1 and the sterile phenotypes of the weak but not the strong taa mutants. In addition, we discovered that the auxin overproduction phenotypes of YUC overexpression lines are dependent on active TAA genes. Our genetic data show that YUC and TAA work in the same pathway and that YUC is downstream of TAA. The yuc mutants accumulate IPA, and the taa mutants are partially IPA-deficient, indicating that TAAs are responsible for converting tryptophan to IPA, whereas YUCs play an important role in converting IPA to indole-3-acetic acid.
Authors:
Christina Won; Xiangling Shen; Kiyoshi Mashiguchi; Zuyu Zheng; Xinhua Dai; Youfa Cheng; Hiroyuki Kasahara; Yuji Kamiya; Joanne Chory; Yunde Zhao
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2011-10-24
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  108     ISSN:  1091-6490     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  2011 Nov 
Date Detail:
Created Date:  2011-11-09     Completed Date:  2012-01-25     Revised Date:  2013-02-14    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  18518-23     Citation Subset:  IM    
Affiliation:
Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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MeSH Terms
Descriptor/Qualifier:
Arabidopsis / enzymology,  genetics,  metabolism*
Arabidopsis Proteins / metabolism*
Genes, Plant
Indoleacetic Acids / metabolism*
Tryptophan Transaminase / metabolism*
Grant Support
ID/Acronym/Agency:
R01 GM052413/GM/NIGMS NIH HHS; R01 GM068631-09/GM/NIGMS NIH HHS; R01GM68631/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Arabidopsis Proteins; 0/Indoleacetic Acids; 6U1S09C61L/indoleacetic acid; EC 2.6.1.27/Tryptophan Transaminase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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