Mechanism of Gene Expression of Arabidopsis Glutathione S-Transferase, AtGST1, and AtGST11 in Response to Aluminum Stress

• Published in: Plant physiology (Bethesda) 2004-04, Vol.134 (4), p.1672-1682
• Main Authors: Bunichi Ezaki, Masakatsu Suzuki, Hirotoshi Motoda, Masako Kawamura, Susumu Nakashima, Matsumoto, Hideaki
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - drug effects; Aluminum; Aluminum - toxicity; Arabidopsis - drug effects; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Base Sequence; Calcium - pharmacology; Environmental Stress and Adaptation; Enzyme Induction - drug effects; Enzyme Induction - genetics; Gene expression; Gene Expression Regulation, Enzymologic - drug effects; Gene Expression Regulation, Plant - drug effects; Genes; Glucuronidase - genetics; Glucuronidase - metabolism; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Leaves; Molecular Sequence Data; Oxidative stress; Plant Leaves - drug effects; Plant Leaves - enzymology; Plant Leaves - genetics; Plant roots; Plant Roots - drug effects; Plant Roots - enzymology; Plant Roots - genetics; Plant Shoots - drug effects; Plant Shoots - enzymology; Plant Shoots - genetics; Plants; Plants, Genetically Modified; Promoter regions; Promoter Regions, Genetic - genetics; Seedlings; Sequence Homology, Nucleic Acid; Signal Transduction - drug effects; Signal Transduction - genetics; Transgenic plants
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.103.037135

The gene expression of two Al-induced Arabidopsis glutathione S-transferase genes, AtGST1 and AtGST11, was analyzed to investigate the mechanism underlying the response to Al stress. An approximately 1-kb DNA fragment of the 5′-upstream region of each gene was fused to a β-glucuronidase (GUS) reporter gene (pAtGST1::GUS and pAtGST11::GUS) and introduced into Arabidopsis ecotype Landsberg erecta. The constructed transgenic lines showed a time-dependent gene expression to a different degree in the root and/or leaf by Al stress. The pAtGST1::GUS gene was induced after a short Al treatment (maximum expression after a 2-h exposure), while the pAtGST11::GUS gene was induced by a longer Al treatment (approximately 8 h for maximum expression). Since the gene expression was observed in the leaf when only the root was exposed to Al stress, a signaling system between the root and shoot was suggested in Al stress. A GUS staining experiment using an adult transgenic line carrying the pAtGST11::GUS gene supported this suggestion. Furthermore, Al treatment simultaneously with various Ca depleted conditions in root region enhanced the gene expression of the pAtGST11::GUS in the shoot region. This result suggested that the degree of Al toxicity in the root reflects the gene response of pAtGST11::GUS in the shoot via the deduced signaling system. Both transgenic lines also showed an increase of GUS activity after cold stress, heat stress, metal toxicity, and oxidative damages, suggesting a common induction mechanism in response to the tested stresses including Al stress.