title: Thymol Mitigates Cadmium Stress by Regulating Glutathione Levels and Reactive Oxygen Species Homeostasis in Tobacco Seedlings.
abstract: Thymol is a famous plant-derived compound that has been widely used in pharmacy due to its antioxidant and antimicrobial properties. However, the modulation of intrinsic plant physiology by thymol remains unclear. It is a significant challenge to confer plant tolerance to Cd (cadmium) stress. In the present study physiological, histochemical, and biochemical methods were applied to investigate thymol-induced Cd tolerance in tobacco (Nicotiana tabacum) seedlings. Thymol was able to alleviate Cd-induced growth inhibition of tobacco seedlings in both dose- and time-dependent manners. Both histochemical detection and in-tube assays suggested that thymol treatment blocked Cd-induced over-generation of reactive oxygen species (ROS), lipid peroxidation, and loss of membrane integrity in both leaves and roots. Thymol decreased Cd-induced cell death that was indicated in vivo by propidium iodide (PI) and trypan blue, respectively. Thymol stimulated glutathione (GSH) biosynthesis by upregulating the expression of γ-glutamylcysteine synthetase 1(GSH1) in Cd-treated seedlings, which may contribute to the alleviation of Cd-induced oxidative injury. In situ fluorescent detection of intracellular Cd2+revealed that thymol significantly decreased free Cd2+in roots, which could be explained by the thymol-stimulated GSH biosynthesis and upregulation of the expression ofphyochelatin synthase 1(PCS1). Taken together, these results suggested that thymol has great potential to trigger plant resistant responses to combat heavy metal toxicity, which may help our understanding of the mechanism for thymol-modulated cell metabolic pathways in response to environmental stimuli.
authors.affiliation: College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. yexiefeng@163.com.
authors.forename: Xiefeng
authors.initials: X
authors.lastname: Ye
authors.affiliation: College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. 18837103304@163.com.
authors.forename: Tianxiao
authors.initials: T
authors.lastname: Ling
authors.affiliation: Nanjing Yangzi Modern Agriculture Investment and Development Co. Ltd., Nanjing 211899, China. hnndxyf@163.com.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Central Laboratory, Jiangsu Academy of Agricultural Science, Nanjing 210014, China. jaasxucunfa@163.com.
authors.forename: Cunfa
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China. zhouweihistfood@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China. hulb973@163.com.
authors.forename: Liangbin
authors.initials: L
authors.lastname: Hu
authors.affiliation: Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China. jacksonchen206@gmail.com.|Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Provincial Department of Agriculture and Forestry, Nanjing 210014, China. jacksonchen206@gmail.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China. shizhiqi@jaas.ac.cn.|Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Provincial Department of Agriculture and Forestry, Nanjing 210014, China. shizhiqi@jaas.ac.cn.
authors.forename: Zhiqi
authors.initials: Z
authors.lastname: Shi
mesh_terms: D002104:Cadmium / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D006706:Homeostasis; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism; D013943:Thymol / Q000494:pharmacology*; D013997:Time Factors; D014026:Nicotiana / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D002104:Cadmium; D013943:Thymol; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione
keywords: cadmium; cell death; glutathione; reactive oxygen species; thymol; tobacco