title: Ethylene and reactive oxygen species are involved in root aerenchyma formation and adaptation of wheat seedlings to oxygen-deficient conditions.
abstract: Exposing plants to hypoxic conditions greatly improves their anoxic stress tolerance by enhancing the activities of glycolysis and fermentation in roots. Ethylene may also be involved in these adaptive responses because its synthesis is increased in roots under hypoxic conditions. Here it is reported that pre-treatment of wheat seedlings with an ethylene precursor, 1-aminocyclopropanecarboxylic acid (ACC), enhanced accumulation of ethylene in the roots of wheat seedlings, and enhanced their tolerance of oxygen-deficient conditions through increasing the expression of genes encoding ethanol fermentation enzymes, alcohol dehydrogenase and pyruvate decarboxylase, in the roots. Lysigenous aerenchyma formation in root was induced by ACC pre-treatment and was further induced by growth under oxygen-deficient conditions. ACC pre-treatment increased the expression of three genes encoding respiratory burst oxidase homologue (a plant homologue of gp91(phox) in NADPH oxidase), which has a role in the generation of reactive oxygen species (ROS), in roots of seedlings. Co-treatment with ACC and an NADPH oxidase inhibitor, diphenyleneiodonium, partly suppressed the ACC-induced responses. These results suggest that ethylene and ROS are involved in adaptation of wheat seedlings to oxygen-deficient conditions through controlling lysigenous aerenchyma formation and the expression of genes encoding ethanol fermentation enzymes.
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Takaki
authors.initials: T
authors.lastname: Yamauchi
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Aya
authors.initials: A
authors.lastname: Fukazawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mori
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Abe
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Oyanagi
authors.forename: Mikio
authors.initials: M
authors.lastname: Nakazono
mesh_terms: D000222:Adaptation, Physiological; D000426:Alcohol Dehydrogenase / Q000235:genetics; D000598:Amino Acids, Cyclic / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005030:Ethylenes / Q000032:analysis / Q000378:metabolism; D005285:Fermentation; D018506:Gene Expression Regulation, Plant; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D009861:Onium Compounds / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000032:analysis / Q000378:metabolism*; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D011767:Pyruvate Decarboxylase / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D015398:Signal Transduction; D013997:Time Factors; D014908:Triticum / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D000598:Amino Acids, Cyclic; D004791:Enzyme Inhibitors; D005030:Ethylenes; D009861:Onium Compounds; D010937:Plant Growth Regulators; D010940:Plant Proteins; D017382:Reactive Oxygen Species; C023863:1-aminocyclopropane-1-carboxylic acid; C007517:diphenyleneiodonium; C036216:ethylene; D000426:Alcohol Dehydrogenase; D019255:NADPH Oxidases; D011767:Pyruvate Decarboxylase; D010100:Oxygen
keywords: Aerenchyma; ethylene; fermentation; oxygen deficiency; reactive oxygen species; wheat (Triticum aestivum L.).