This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 136/2/3209    most recent pp.104.047068v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Ohkama-Ohtsu, N. Articles by Naito, S. Search for Related Content PubMed PubMed Citation Articles by Ohkama-Ohtsu, N. Articles by Naito, S. Agricola Articles by Ohkama-Ohtsu, N. Articles by Naito, S.

PLANT NUTRITION

Isolation and Characterization of an Arabidopsis Mutant That Overaccumulates O-Acetyl-L-Ser^1,[w]

Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo 060–8589, Japan (N.O.-O., S.N.); Department of Applied Biological Chemistry, Graduate School of Agricultural Life Sciences (I.K.), and Biotechnology Research Center (T.F.), The University of Tokyo, Tokyo 113–8657; and Precursory Research for Embryonic Science and Technology, Japan Science and Technology Corporation, Kawaguchi, Saitama 332–0012, Japan (T.F.)

O-Acetyl-L-Ser (OAS) is a positive regulator for the expression of sulfur (S) deficiency-inducible genes. In this study, through the isolation and analysis of Arabidopsis mutants exhibiting altered expression of S-responsive genes, we identified a thiol reductase as a regulator of the OAS levels. Ethyl methanesulfonate-mutagenized M2 seeds of transgenic Arabidopsis NOB7 carrying a chimeric S-responsive promoter driving the green fluorescent protein gene were screened for mutants with altered levels of green fluorescence compared to parental NOB7 line. One of the lines exhibited elevated levels of green fluorescence and mRNA accumulation of several endogenous S-responsive genes and carried a single recessive mutation responsible for the phenotype. OAS concentration in the rosette leaves of the mutant was about five times higher than that of wild-type plants. Based upon the high OAS levels, the mutant was named osh1-1 (OAS high accumulation). The OSH1 locus was mapped to a 30-kb region in chromosome V. DNA sequence analysis revealed no base change in this region; however, a demethylated C residue was found in the first exon of At5g01580. At5g01580 mRNA accumulation was higher in osh1-1 than in wild type, while transcript levels of other genes in the mapped region were not significantly altered in osh1-1. A line of transgenic plants overexpressing At5g01580 had elevated levels of endogenous S-responsive genes. These results suggest that elevated expression of At5g01580 is the cause of osh1 phenotype. Based on sequence similarity to animal thiol reductases, At5g01580 was tested for and exhibited thiol reductase activity. Possible roles of a thiol reductase in OAS metabolism are discussed.

² Present address: Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011.

^[w] The online version of this article contains Web-only data.

Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.104.047068.

^* Corresponding author; e-mail atorufu{at}mail.ecc.u-tokyo.ac.jp; fax 81–3–5841–2408.

Received June 1, 2004; returned for revision July 26, 2004; accepted July 26, 2004.

This article has been cited by other articles:

				K. Loizeau, V. De Brouwer, B. Gambonnet, A. Yu, J.-P. Renou, D. Van Der Straeten, W. E. Lambert, F. Rebeille, and S. Ravanel A Genome-Wide and Metabolic Analysis Determined the Adaptive Response of Arabidopsis Cells to Folate Depletion Induced by Methotrexate Plant Physiology, December 1, 2008; 148(4): 2083 - 2095. [Abstract] [Full Text] [PDF]

				J.-P. Reichheld, M. Khafif, C. Riondet, M. Droux, G. Bonnard, and Y. Meyer Inactivation of Thioredoxin Reductases Reveals a Complex Interplay between Thioredoxin and Glutathione Pathways in Arabidopsis Development PLANT CELL, June 1, 2007; 19(6): 1851 - 1865. [Abstract] [Full Text] [PDF]