Glutathione peroxidase genes inArabidopsisare ubiquitous and regulated by abiotic stresses through diverse signaling pathways

• Published in: The Plant journal : for cell and molecular biology 2003-12, Vol.36 (5), p.602
• Main Authors: Milla, Miguel A. Rodriguez, Maurer, Alberto, Huete, Alicia Rodriguez, Gustafson, J. Perry
• Format: Article
• Language: English
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.2003.01901.x

Summary Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage generated by reactive oxygen species (ROS). 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- AtGPX7 inArabidopsiswas identified, and the genomic organization of this family was reported. The putative subcellular localizations of the encoded proteins are the cytosol, chloroplast, mitochondria, and endoplasmic reticulum. Expressed sequence tags (ESTs) for all the genes exceptAtGPX7were identified. Expression analysis ofAtGPXgenes inArabidopsistissues was performed, and different patterns were detected. Interestingly, several genes were up-regulated coordinately in response to abiotic stresses.AtGPX6, like humanphospholipid hydroperoxide GPX(PHGPX), possibly encodes mitochondrial and cytosolic isoforms by alternative initiation. In addition, this gene showed the strongest responses under most abiotic stresses tested.AtGPX6::GUSanalysis in transgenicArabidopsisshowed thatAtGPX6is 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 (SA), jasmonic acid (JA), abscisic acid (ABA), 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 theAtGPXgenes 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.