Ozone-induced expression of the Arabidopsis FAD7 gene requires salicylic acid, but not NPR1 and SID2.
The Arabidopsis FAD7 gene encodes a plastid omega-3 fatty acid desaturase that catalyzes the desaturation of dienoic fatty acids to trienoic fatty acids in chloroplast membrane lipids. The expression of FAD7 was rapidly and locally induced by ozone exposure, which causes oxidative responses equivalent to pathogen-induced hypersensitive responses and subsequently activates various defense-related genes. This induction was reduced in salicylic acid (SA)-deficient NahG plants expressing SA hydroxylase, but was unaffected in etr1 and jar1 mutants, which are insensitive to ethylene and jasmonic acid (JA), respectively. The SA dependence of the FAD7 induction was confirmed by the exogenous application of SA. SA-induced expression of FAD7 in the npr1 mutant which is defective in an SA signaling pathway occurred to the same extent as in the wild type. Furthermore, in the sid2 mutant which lacks an enzyme required for SA biosynthesis, the expression of FAD7 was induced by ozone exposure. These results suggest that the ozone-induced expression of FAD7 gene requires SA, but not ethylene, JA, NPR1 and SID2.
Yaeno
Takashi
T
Department of Biology, Faculty of Sciences, Kyushu University, Hakozaki, Fukuoka, Japan.
Saito
Bunnai
B
Katsuki
Tsutomu
T
Iba
Koh
K
D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D019751:Intramolecular Transferases / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009713:Nucleotidyltransferases / Q000235:genetics; D054883:Oxylipins; D010126:Ozone / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics; D020156:Salicylic Acid / Q000378:metabolism / Q000494:pharmacology*; D015398:Signal Transduction; D013997:Time Factors; D010453:Peptide Synthases
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005030:Ethylenes; D044943:Fatty Acid Desaturases; D019751:Intramolecular Transferases; D006899:Mixed Function Oxygenases; D009713:Nucleotidyltransferases; D054883:Oxylipins; D010126:Ozone; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D020156:Salicylic Acid; C494590:ETR1 protein, Arabidopsis; C105496:NPR1 protein, Arabidopsis; C011006:jasmonic acid; C036216:ethylene; C022619:salicylate 1-monooxygenase; C084083:Fad7 protein, Arabidopsis; C058486:isochorismate synthase; C412831:AT2G46370 protein, Arabidopsis; D010453:Peptide Synthases