title: Increased tolerance to salt stress in OPDA-deficient rice ALLENE OXIDE CYCLASE mutants is linked to an increased ROS-scavenging activity.
abstract: Salinity stress represents a global constraint for rice, the most important staple food worldwide. Therefore the role of the central stress signal jasmonate for the salt response was analysed in rice comparing the responses to salt stress for two jasmonic acid (JA) biosynthesis rice mutants (cpm2 and hebiba) impaired in the function of ALLENE OXIDE CYCLASE (AOC) and their wild type. The aoc mutants were less sensitive to salt stress. Interestingly, both mutants accumulated smaller amounts of Na(+) ions in their leaves, and showed better scavenging of reactive oxygen species (ROS) under salt stress. Leaves of the wild type and JA mutants accumulated similar levels of abscisic acid (ABA) under stress conditions, and the levels of JA and its amino acid conjugate, JA-isoleucine (JA-Ile), showed only subtle alterations in the wild type. In contrast, the wild type responded to salt stress by strong induction of the JA precursor 12-oxophytodienoic acid (OPDA), which was not observed in the mutants. Transcript levels of representative salinity-induced genes were induced less in the JA mutants. The absence of 12-OPDA in the mutants correlated not only with a generally increased ROS-scavenging activity, but also with the higher activity of specific enzymes in the antioxidative pathway, such as glutathione S-transferase, and fewer symptoms of damage as, for example, indicated by lower levels of malondialdehyde. The data are interpreted in a model where the absence of OPDA enhanced the antioxidative power in mutant leaves.
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Centre (ARC), Giza, Egypt.
authors: Mohamed
authors: M
authors: Hazman
authors: Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry (IPB), Halle, Germany.
authors: Bettina
authors: B
authors: Hause
authors: Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
authors: Elisabeth
authors: E
authors: Eiche
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany.
authors: Peter
authors: P
authors: Nick
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany michael.riemann@kit.edu.
authors: Michael
authors: M
authors: Riemann
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D007532:Isoleucine / Q000031:analogs & derivatives / Q000378:metabolism; D015227:Lipid Peroxidation; D012275:Oryza / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D017382:Reactive Oxygen Species; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; D012965:Sodium Chloride; C025999:12-oxophytodienoic acid; C011006:jasmonic acid; D000040:Abscisic Acid; D005982:Glutathione Transferase; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase
keywords: 12-oxophytodienoic acid (12-OPDA); ALLENE OXIDE CYCLASE (AOC); Oryza sativa; jasmonate; oxidative stress; reactive oxygen species (ROS); salinity.