title: Subcellular distribution and chemical forms of thorium in Brassica juncea var. foliosa.
abstract: Brassica juncea var. foliosa (B. juncea var. foliosa) is a promising species for thorium (Th) phytoextraction due to its large biomass, fast growth rate and high tolerance toward Th. To further understand the mechanisms of Th tolerance, the present study investigated the subcellular distribution and chemical forms of Th found in B. juncea var. foliosa Our results indicated that in both roots and leaves, Th contents in different parts of the cells follow the order of cell wall > membranes and soluble fraction > organelles. In particular, Transmission Electron Microscope (TEM) analysis showed that Th was abundantly located in cell walls of the roots. Additionally, when plants were exposed to different concentrations of Th, we have found that Th existed in B. juncea var. foliosa with different chemical forms. Much of the Th extracted by 2% acetic acid (HAc), 1 M NaCl and HCl in roots with the percentage distribution varied from 47.2% to 62.5%, while in leaves, most of the Th was in the form of residue and the subdominant amount of Th was extracted by HCl, followed by 2% HAc. This suggested that Th compartmentation in cytosol and integration with phosphate or proteins in cell wall might be responsible for the tolerance of B. juncea var. foliosa to the stress of Th.
authors.affiliation: College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Sai
authors.initials: S
authors.lastname: Zhou
authors.affiliation: College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Hailu
authors.initials: H
authors.lastname: Kai
authors.affiliation: Logistic Engineering University, Chongqing 401311, China.
authors.forename: Zhongyong
authors.initials: Z
authors.lastname: Zha
authors.affiliation: Logistic Engineering University, Chongqing 401311, China.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Fang
authors.affiliation: College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Dingna
authors.initials: D
authors.lastname: Wang
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Du
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Logistic Engineering University, Chongqing 401311, China. Electronic address: fxjhg@126.com.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Feng
authors.affiliation: College of Chemistry, Sichuan University, Chengdu 610064, China. Electronic address: jinyongdong@scu.edu.cn.
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Jin
authors.affiliation: College of Chemistry, Sichuan University, Chengdu 610064, China. Electronic address: xiachqin@163.com.
authors.forename: Chuanqin
authors.initials: C
authors.lastname: Xia
mesh_terms: D002473:Cell Wall / Q000378:metabolism / Q000648:ultrastructure; D003600:Cytosol / Q000378:metabolism / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009149:Mustard Plant / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018547:Plant Stems / Q000187:drug effects / Q000378:metabolism; D013910:Thorium / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D013910:Thorium
keywords: Chemical form; Subcellular distribution; Th; Toxicity