title: Glutathione homeostasis and Cd tolerance in the Arabidopsis sultr1;1-sultr1;2 double mutant with limiting sulfate supply.
abstract: Cadmium sensitivity in sultr1;1 - sultr1;2 double mutant with limiting sulfate supply is attributed to the decreased glutathione content that affected oxidative defense but not phytochelatins' synthesis. In plants, glutathione (GSH) homeostasis plays pivotal role in cadmium (Cd) detoxification. GSH is synthesized by sulfur (S) assimilation pathway. Many studies have tried to investigate the role of GSH homeostasis on Cd tolerance using mutants; however, most of them have focused on the last few steps of S assimilation. Until now, mutant evidence that explored the relationship between GSH homeostasis on Cd tolerance and S absorption is rare. To further reveal the role of GSH homeostasis on Cd stress, the wild-type and a sultr1;1-sultr1;2 double mutant which had a defect in two distinct high-affinity sulfate transporters were used in this study. Growth parameters, biochemical or zymological indexes and S assimilation-related genes' expression were compared between the mutant and wild-type Arabidopsis plants. It was found that the mutations of SULTR1;1 and SULTR1;2 did not affect Cd accumulation. Compared to the wild-type, the double mutant was more sensitive to Cd under limited sulfate supply and suffered from stronger oxidative damage. More importantly, under the same condition, lower capacity of S assimilation resulted in decreased GSH content in mutant. Faced to the limited GSH accumulation, mutant seedlings consumed a large majority of GSH in pool for the synthesis of phytochelatins rather than participating in the antioxidative defense. Therefore, homeostasis of GSH, imbalance between antioxidative defense and severe oxidative damage led to hypersensitivity of double mutant to Cd under limited sulfate supply.
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.|Colleges of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, Zhejiang, People's Republic of China.
authors.forename: Fei-Hua
authors.initials: FH
authors.lastname: Wu
authors.affiliation: Marine Ecology Research Center, First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, Shandong, People's Republic of China.
authors.forename: Jing-Xi
authors.initials: JX
authors.lastname: Li
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Wang
authors.affiliation: Fujian Key Laboratory of Subtropical Plant Physiology and Biochemistry, Fujian Institute of Subtropical Botany, Xiamen, 361005, Fujian, People's Republic of China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Wang
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.|Sericultural Research Institute, Zhejiang Academy of Agricultural Science, Hangzhou, 310021, Zhejiang, People's Republic of China.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Hu
authors.affiliation: Marine Ecology Research Center, First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, Shandong, People's Republic of China.
authors.forename: Li-Jie
authors.initials: LJ
authors.lastname: Gao
authors.affiliation: Marine Ecology Research Center, First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, Shandong, People's Republic of China.
authors.forename: Zong-Ling
authors.initials: ZL
authors.lastname: Wang
authors.affiliation: Marine Ecology Research Center, First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, Shandong, People's Republic of China.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Chen
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.
authors.forename: Martin
authors.initials: M
authors.lastname: Simon
authors.affiliation: Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China. zhenghl@xmu.edu.cn.
authors.forename: Hai-Lei
authors.initials: HL
authors.lastname: Zheng
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D002104:Cadmium / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D002104:Cadmium; D013455:Sulfur; D005978:Glutathione
keywords: Antioxidative defense; Arabidopsis; Cadmium toxicity; Glutathione homeostasis; Sulfate transporter; Sulfur assimilation-related genes