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United States Department of Agriculture

Agricultural Research Service

Title: Glutathione Peroxidase Genes in Arabidopsis Are Ubiquitous and Regulated by Abiotic Stresses Through Diverse Signaling Pathways

Authors
item Rodriguez Milla, Miguel - UNIV OF MISSOURI
item Maurer, Alberto - UNIV OF MISSOURI
item Rodriguez Huete, Alicia - UNIV OF MISSOURI
item Gustafson, J

Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 21, 2003
Publication Date: December 2, 2003
Citation: Rodriguez Milla, M.A., Maurer, A., Rodriguez Huete, A., Gustafson, J.P. 2003.Glutathione peroxidase genes in arabidopsis are ubiquitous and regulated by abiotic stresses through diverse signaling pathways. The Plant Cell. 36(5):602-615.

Interpretive Summary: Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage. The presence of GPXs in plants has been reported, but the roles of individual members of this family in a single plant species have not been studied. A family of seven related proteins were identified and located to the cytosol, chloroplast, mitochondria, and endoplasmic reticulum. Expressed sequence were identified and analyzed. Several of them were expressed in response to abiotic stresses, and are highly expressed throughout development in most tissues, thus supporting an important role for this gene in protection against oxidative damage. These results will benefit geneticists and breeders attempting to analyze gene expression in cereals.

Technical Abstract: Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage generated by reactive oxygen species. The presence of GPXs in plants has been reported by several groups, but the roles of individual members of this family in a single plant species have not been studied. A family of seven related proteins named AtGPX1-7 in Arabidopsis was identified and the genomic organization of this family reported. The putative subcellular localizations of the encoded proteins are the cytosol, chloroplast, mitochondria, and endoplasmic reticulum. Expressed sequence tags for all the genes except AtGPX7 were identified. Expression analysis of AtGPX genes in Arabidopsis tissues was performed and different patterns were detected. Interestingly, several genes were coordinately up-regulated in response to abiotic stresses. AtGPX6, like human phospholipid hydroperoxide GPX, possibly encodes mitochondrial and cytosolic isoforms by alternative initiation. In addition, this gene showed the strongest responses under most abiotic stresses tested. AtGPX6::GUS analysis in transgenic Arabidopsis showed that AtGPX6 was highly expressed throughout development in most tissues, thus supporting an important role for this gene in protection against oxidative damage. The different effects of salicylic acid, jasmonic acid, abscisic acid, and auxin on the expression of the genes indicate that the AtGPX family is regulated by multiple signaling pathways. Analysis of the upstream region of the AtGPX genes revealed the presence of multiple conserved motifs and some of them resembled antioxidant-responsive elements found in plant and human promoters. The potential regulatory role of specific sequences is discussed.

Last Modified: 7/25/2014
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