Regulation of the Arabidopsis thaliana vitamin B6 biosynthesis genes by abiotic stress.

Full Abstract

Vitamin B(6) (pyridoxine and its vitamers) plays an essential role as a co-factor for enzymatic reactions and has also recently been implicated in defense against cellular oxidative stress. The biosynthetic pathway was thoroughly characterized in Escherichia coli, however most organisms, including plants, utilize an alternate pathway involving two genes, PDX1 and PDX2. Arabidopsis thaliana contains one copy of PDX2, but three full-length copies of PDX1, one each on chromosomes 2, 3, and 5 (referred to as PDX1.1, PDX1.2, and PDX1.3, respectively). Phylogenetic analysis of the PDX1 homologues in A. thaliana showed that PDX1.1 and PDX1.3 clustered with the homologues from the other dicots, whereas PDX1.2 was more divergent, and did not cluster with either the dicots or monocots. Expression analysis using quantitative PCR showed that PDX1.1 and PDX1.3 were highly expressed in A. thaliana rosettes, while PDX1.2 showed only low level expression. All three PDX1 genes and PDX2 were responsive to abiotic stressors including high light, chilling, drought, and ozone, however, the response of PDX1.2 was disparate from that of the other PDX genes, showing a lessened response to high light, chilling, and drought, but an increased response to ozone. Green fluorescent protein fusion studies demonstrated that PDX2 localizes in the nucleus and membranes of cells, consistent with recent published data for PDX1. Insight into regulation of the biosynthetic genes during abiotic stress could have important applications in the development of stress-tolerant crops.

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Author information

Author/s: Denslow, Sheri A (SA); Rueschhoff, Elizabeth E (EE); Daub, Margaret E (ME);

Affiliation: Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695-7616, USA.

Journal and publication information

Publication Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.

Journal: Plant physiology and biochemistry : PPB / Société française de physiologie végétale (Plant Physiol Biochem), published in France. (Language: eng)

Reference: 2007-Feb; vol 45 (issue 2) : pp 152-61

Dates: Created 2007/03/26; Completed 2007/06/18;

PMID: 17344055, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Antioxidants - metabolism
Arabidopsis - metabolism
Arabidopsis Proteins - metabolism; physiology
Escherichia coli - metabolism
Gene Expression Regulation, Plant
Genes, Plant
Green Fluorescent Proteins - metabolism
Microscopy, Fluorescence

Microscopy, Fluorescence
Nitrogenous Group Transferases - metabolism; physiology
Oxidative Stress
Phylogeny
Plant Proteins - metabolism
RNA, Messenger - metabolism
Time Factors
Vitamin B 6 - metabolism

Associated Chemicals: Antioxidants (0) ; Arabidopsis Proteins (0) ; Plant Proteins (0) ; RNA, Messenger (0) ; Green Fluorescent Proteins (147336-22-9) ; Vitamin B 6 (8059-24-3) ; Nitrogenous Group Transferases (EC 2.6.-) ; PDX1 protein, Arabidopsis (EC 2.6.-) ; PDX2 protein, Arabidopsis (EC 2.6.-)

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