title: The reduction of reactive oxygen species formation by mitochondrial alternative respiration in tomato basal defense against TMV infection.
abstract: The role of mitochondrial alternative oxidase (AOX) and the relationship between systemic AOX induction, ROS formation, and systemic plant basal defense to Tobacco mosaic virus (TMV) were investigated in tomato plants. The results showed that TMV inoculation significantly increased the level of AOX gene transcripts, ubiquinone reduction levels, pyruvate content, and cyanide-resistant respiration (CN-resistant R) in upper, un-inoculated leaves. Pretreatment with potassium cyanide (KCN, a cytochrome pathway inhibitor) greatly increased CN-resistant R and reduced reactive oxygen species (ROS) formation, while application of salicylhydroxamic acid (SHAM, an AOX inhibitor) blocked the AOX activity and enhanced the production of ROS in the plants. Furthermore, TMV systemic infection was enhanced by SHAM and reduced by KCN pretreatment, as compared with the un-pretreated TMV counterpart. In addition, KCN application significantly diminished TMV-induced increase in antioxidant enzyme activities and dehydroascorbate/total ascorbate pool, while an opposite change was observed with SHAM-pretreated plants. These results suggest that the systemic induction of the mitochondrial AOX pathway plays a critical role in the reduction of ROS to enhance basal defenses. Additional antioxidant systems were also coordinately regulated in the maintenance of the cellular redox homeostasis.
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, 310058 Hangzhou, People's Republic of China.
authors.forename: Yang-Wen-Ke
authors.initials: YW
authors.lastname: Liao
authors.forename: Kai
authors.initials: K
authors.lastname: Shi
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Fu
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: De-Kun
authors.initials: DK
authors.lastname: Dong
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Jiang
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Zhou
authors.forename: Xiao-Jian
authors.initials: XJ
authors.lastname: Xia
authors.forename: Wu-Sheng
authors.initials: WS
authors.lastname: Liang
authors.forename: Jing-Quan
authors.initials: JQ
authors.lastname: Yu
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D019069:Cell Respiration; D003683:Dehydroascorbic Acid / Q000378:metabolism; D060467:Disease Resistance; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000821:virology*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011190:Potassium Cyanide / Q000494:pharmacology; D019289:Pyruvic Acid / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012457:Salicylamides / Q000494:pharmacology; D014027:Tobacco Mosaic Virus / Q000276:immunology / Q000472:pathogenicity*; D014158:Transcription, Genetic; D014451:Ubiquinone / Q000378:metabolism; D000099188:Alternative Oxidase
chemical_list: D000975:Antioxidants; D003683:Dehydroascorbic Acid; D004791:Enzyme Inhibitors; D006861:Hydrogen Peroxide; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D011190:Potassium Cyanide; D019289:Pyruvic Acid; D017382:Reactive Oxygen Species; D012457:Salicylamides; D014451:Ubiquinone; D000099188:Alternative Oxidase; C005703:salicylhydroxamic acid