title: Relationship between cultivar difference in the sensitivity of net photosynthesis to ozone and reactive oxygen species scavenging system in Japanese winter wheat (Triticum aestivum).
abstract: To clarify the relationship between cultivar difference in the sensitivity of net photosynthesis to ozone (O(3)) and the reactive oxygen species (ROS) scavenging system in wheat (Triticum aestivum), we investigated the effects of chronic exposure to ambient levels of O(3) on gas exchange rates, activity and concentration of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), activity of ROS scavenging enzymes and concentration of antioxidants of the flag leaf in two Japanese winter wheat cultivars (Norin 61 and Shirogane-komugi). Although the net photosynthetic rate of the flag leaf in Norin 61 was not significantly reduced by exposure to O(3), that in Shirogane-komugi was significantly reduced by the exposure to O(3) during the anthesis and early grain-filling stages. In the two cultivars, stomatal diffusive conductance to H(2) O of the flag leaf was not significantly affected by the exposure to O(3). The exposure to O(3) induced significant reductions in the activity and concentration of Rubisco, activities of catalase (CAT) and monodehydroascorbate reductase (MDAR) and concentrations of reduced form of ascorbate and total glutathione of the flag leaf in Shirogane-komugi. It was concluded that the sensitivity of net photosynthesis of flag leaf to O(3) is higher in Shirogane-komugi than in Norin 61, and the difference in the sensitivity to O(3) between the two cultivars is mainly due to that in the effects of O(3) on the detoxification ability of ROS, mainly determined by the activity of ROS scavenging enzymes, such as CAT and MDAR.
authors.affiliation: Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Inada
authors.forename: Taisuke
authors.initials: T
authors.lastname: Kondo
authors.forename: Nahid
authors.initials: N
authors.lastname: Akhtar
authors.forename: Daiki
authors.initials: D
authors.lastname: Hoshino
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Izuta
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D014644:Genetic Variation; D005838:Genotype; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007564:Japan; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D010126:Ozone / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D013312:Stress, Physiological; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D010126:Ozone; D006861:Hydrogen Peroxide; D002374:Catalase; D009247:NADH, NADPH Oxidoreductases; C023927:monodehydroascorbate reductase (NADH); D012273:Ribulose-Bisphosphate Carboxylase; D005978:Glutathione; D001205:Ascorbic Acid