title: Salicylic acid mediates antioxidant defense system and ABA pathway related gene expression in Oryza sativa against quinclorac toxicity.
abstract: The auxin herbicide quinclorac is widely used for controlling weeds in transplanted and direct-seeded rice fields. However, its phytotoxic responses on rice are still unknown. Therefore, in the present investigation we studied the effects of different concentrations (0, 0.1 and 0.5g/L) of quinclorac herbicide on the physiological and biochemical changes of two rice cultivars (XS 134 and ZJ 88) and further analyzed the ameliorating role of salicylic acid (SA) on quinclorac toxicity in rice plants. The results revealed that exogenous application of SA significantly increased plant biomass and total chlorophyll contents in herbicide stressed plants. The lipid peroxidation and ROS (H2O2, O2(-.), (-)OH) production were significantly increased in roots and leaves of both rice cultivars under quinclorac stress, demonstrating an oxidative burst in rice plants. Whereas, application of SA significantly lowered ROS contents under quinclorac stress. Further, exogenous SA treatment significantly modulated antioxidant enzymes and enhanced GSH concentration in stress plants. Anatomical observations of leaf and root revealed that herbicide affected internal structures, while SA played a vital role in protection from toxic effects. Expression analysis of stress hormone ABA genes (OsABA8oxs, OsNCEDs) revealed that quinclorac application enhanced stress condition in cultivar ZJ 88, while SA treatment downregulated ABA genes more in cultivar XS 134, which correlated with the enhanced tolerance to quinclorac induced oxidative stress in this cultivar. The present study delineated that SA played a critical role under quinclorac stress in both rice cultivars by regulating antioxidant defense system, reducing ROS formation and preventing the degradation of internal cell organelles.
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
authors.forename: Mengting
authors.initials: M
authors.lastname: Lv
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
authors.forename: Faisal
authors.initials: F
authors.lastname: Islam
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
authors.forename: Rafaqat A
authors.initials: RA
authors.lastname: Gill
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Yang
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China; Institute of Crop Science and Resource Conservation (INRES), Abiotic Stress Tolerance in Crops, University of Bonn, 53115 Bonn, Germany.
authors.forename: Basharat
authors.initials: B
authors.lastname: Ali
authors.affiliation: School of Plant Biology, Faculty of Science and The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009, Australia.
authors.forename: Guijun
authors.initials: G
authors.lastname: Yan
authors.affiliation: Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China. Electronic address: wjzhou@zju.edu.cn.
authors.forename: Weijun
authors.initials: W
authors.lastname: Zhou
mesh_terms: D000040:Abscisic Acid / Q000235:genetics / Q000378:metabolism*; D000975:Antioxidants / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D005982:Glutathione Transferase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D058503:Mesophyll Cells / Q000187:drug effects / Q000648:ultrastructure; D012275:Oryza / Q000254:growth & development / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D018515:Plant Leaves / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects; D011804:Quinolines / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D011804:Quinolines; D017382:Reactive Oxygen Species; D002734:Chlorophyll; C489048:quinclorac; D008315:Malondialdehyde; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D005982:Glutathione Transferase; D020156:Salicylic Acid
keywords: Glutathione transferases; OsABA8oxs genes; OsNCEDs genes; Oxidative stress; Quinclorac stress; Rice; Salicylic acid