Glutathione metabolic genes coordinately respond to heavy metals and jasmonic acid in Arabidopsis.
Glutathione plays a pivotal role in protecting plants from environmental stresses, oxidative stress, xenobiotics, and some heavy metals. Arabidopsis plants treated with cadmium or copper responded by increasing transcription of the genes for glutathione synthesis, gamma-glutamylcysteine synthetase and glutathione synthetase, as well as glutathione reductase. The response was specific for those metals whose toxicity is thought to be mitigated through phytochelatins, and other toxic and nontoxic metals did not alter mRNA levels. Feeding experiments suggested that neither oxidative stress, as results from exposure to H2O2, nor oxidized or reduced glutathione levels were responsible for activating transcription of these genes. Jasmonic acid also activated the same suite of genes, which suggests that it might be involved in the signal transduction pathway for copper and cadmium. Jasmonic acid treatment increased mRNA levels and the capacity for glutathione synthesis but did not alter the glutathione content in unstressed plants, which supports the idea that the glutathione concentration is controlled at multiple levels.
Xiang
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Department of Botany, Iowa State University, Ames, Iowa 50011-1020, USA.
Oliver
D J
DJ
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D003517:Cyclopentanes / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D017343:Genes, Plant / Q000187:drug effects; D005978:Glutathione / Q000096:biosynthesis / Q000378:metabolism*; D006706:Homeostasis; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008667:Metalloproteins / Q000096:biosynthesis; D019216:Metals, Heavy / Q000633:toxicity; D018384:Oxidative Stress; D054883:Oxylipins; D054811:Phytochelatins; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000096:biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
D003517:Cyclopentanes; D008667:Metalloproteins; D019216:Metals, Heavy; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; C011006:jasmonic acid; D054811:Phytochelatins; D006861:Hydrogen Peroxide; D005978:Glutathione