title: Salicylic acid binding of mitochondrial alpha-ketoglutarate dehydrogenase E2 affects mitochondrial oxidative phosphorylation and electron transport chain components and plays a role in basal defense against tobacco mosaic virus in tomato.
abstract: Salicylic acid (SA) plays a critical role in plant defense against pathogen invasion. SA-induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense and involves a specific pathway mediated by mitochondria; however, the underlying mechanisms remain largely unknown. The SA-binding activity of the recombinant tomato (Solanum lycopersicum) alpha-ketoglutarate dehydrogenase (Slα-kGDH) E2 subunit of the tricarboxylic acid (TCA) cycle was characterized. The biological role of this binding in plant defenses against tobacco mosaic virus (TMV) was further investigated via Slα-kGDH E2 silencing and transient overexpression in plants. Slα-kGDH E2 was found to bind SA in two independent assays. SA treatment, as well as Slα-kGDH E2 silencing, increased resistance to TMV. SA did not further enhance TMV defense in Slα-kGDH E2-silenced tomato plants but did reduce TMV susceptibility in Nicotiana benthamiana plants transiently overexpressing Slα-kGDH E2. Furthermore, Slα-kGDH E2-silencing-induced TMV resistance was fully blocked by bongkrekic acid application and alternative oxidase 1a silencing. These results indicated that binding by Slα-kGDH E2 of SA acts upstream of and affects the mitochondrial electron transport chain, which plays an important role in basal defense against TMV. The findings of this study help to elucidate the mechanisms of SA-induced viral defense.
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.|College of Biology and the Environment, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, China.
authors.forename: Yangwenke
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Boyce Thompson Institute for Plant Research, 533 Tower Road, Ithaca, NY, 14853, USA.|Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, 96822, USA.
authors.forename: Miaoying
authors.initials: M
authors.lastname: Tian
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Xia
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.|Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Jingquan
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Horticulture, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Shi
authors.affiliation: Boyce Thompson Institute for Plant Research, 533 Tower Road, Ithaca, NY, 14853, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Klessig
mesh_terms: D019069:Cell Respiration; D060467:Disease Resistance / Q000276:immunology; D004579:Electron Transport; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D007655:Ketoglutarate Dehydrogenase Complex / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000201:enzymology / Q000276:immunology* / Q000821:virology*; D008928:Mitochondria / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D010935:Plant Diseases / Q000276:immunology / Q000821:virology; D010940:Plant Proteins / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism*; D014026:Nicotiana / Q000276:immunology; D014027:Tobacco Mosaic Virus / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D007655:Ketoglutarate Dehydrogenase Complex; D020156:Salicylic Acid
keywords: Solanum lycopersicum (tomato); Solanum lycopersicum alpha-ketoglutarate dehydrogenase (Slα-kGDH) E2; alternative oxidase; mitochondrial electron transport chain; plant-pathogen interactions; salicylic acid (SA); salicylic acid-binding protein; tobacco mosaic virus (TMV)