title: Effects of Cadmium Treatment on the Uptake and Translocation of Sulfate in Arabidopsis thaliana.
abstract: Cadmium (Cd) is a highly toxic and non-essential element for plants, whereas phytochelatins and glutathione are low-molecular-weight sulfur compounds that function as chelators and play important roles in detoxification. Cadmium exposure is known to induce the expression of sulfur-assimilating enzymes and sulfate uptake by roots. However, the molecular mechanism underlying Cd-induced changes remains largely unknown. Accordingly, we analyzed the effects of Cd treatment on the uptake and translocation of sulfate and accumulation of thiols in Arabidopsis thaliana Both wild type (WT) and null mutant (sel1-10 and sel1-18) plants of the sulfate transporter SULTR1;2 exhibited growth inhibition when treated with CdCl2However, the mutant plants exhibited a lower growth rate and lower Cd accumulation. Cadmium treatment also upregulated the transcription of SULTR1;2 and sulfate uptake activity in WT plants, but not in mutant plants. In addition, the sulfate, phytochelatin and total sulfur contents were preferentially accumulated in the shoots of both WT and mutant plants treated with CdCl2, and sulfur K-edge XANES spectra suggested that sulfate was the main compound responsible for the increased sulfur content in the shoots of CdCl2-treated plants. Our results demonstrate that Cd-induced sulfate uptake depends on SULTR1;2 activity, and that CdCl2treatment greatly shifts the distribution of sulfate to shoots, increases the sulfate concentration of xylem sap and upregulates the expression of SULTRs involved in root-to-shoot sulfate transport. Therefore, we conclude that root-to-shoot sulfate transport is stimulated by Cd and suggest that the uptake and translocation of sulfate in CdCl2-treated plants are enhanced by demand-driven regulatory networks.
authors: Graduate School of Agricultural Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors: Chisato
authors: C
authors: Yamaguchi
authors: Faculty of Bioscience, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-town, Fukui 910-1195, Japan.
authors: Yuki
authors: Y
authors: Takimoto
authors: Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
authors: Naoko
authors: N
authors: Ohkama-Ohtsu
authors: Department of Green and Sustainable Chemistry School of Engineering, Tokyo Denki University, 5 Senju-Asahicho, Adachi, Tokyo 120-8551, Japan.
authors: Akiko
authors: A
authors: Hokura
authors: NARO Hokkaido Agricultural Research Center, 1 Hitsujigaoka, Toyohira-ku, Sapporo, 062-8555, Japan.|Present address: Agricultural Radiation Research Center, NARO Tohoku Agricultural Research Center, 50 Aza-Harajyukuminami, Arai, Fukushima, 210-2156.
authors: Takuro
authors: T
authors: Shinano
authors: Graduate School of Agricultural Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors: Toshiki
authors: T
authors: Nakamura
authors: Graduate School of Agricultural Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors: Akiko
authors: A
authors: Suyama
authors: Graduate School of Agricultural Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan amaru@agr.kyushu-u.ac.jp.|Faculty of Bioscience, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-town, Fukui 910-1195, Japan.
authors: Akiko
authors: A
authors: Maruyama-Nakashita
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002104:Cadmium / Q000494:pharmacology*; D003545:Cysteine / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects; D054811:Phytochelatins / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism; D052584:Xylem / Q000187:drug effects / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D013431:Sulfates; D013438:Sulfhydryl Compounds; D002104:Cadmium; D013455:Sulfur; D054811:Phytochelatins; D005978:Glutathione; D003545:Cysteine
keywords: 
  Arabidopsis thaliana
  ; Cadmium tolerance; K- edge XANES; Sulfate assimilation; Sulfate transporter