title: Nickel biopathways in tropical nickel hyperaccumulating trees from Sabah (Malaysia).
abstract: The extraordinary level of accumulation of nickel (Ni) in hyperaccumulator plants is a consequence of specific metal sequestering and transport mechanisms, and knowledge of these processes is critical for advancing an understanding of transition element metabolic regulation in these plants. The Ni biopathways were elucidated in three plant species, Phyllanthus balgooyi, Phyllanthus securinegioides (Phyllanthaceae) and Rinorea bengalensis (Violaceae), that occur in Sabah (Malaysia) on the Island of Borneo. This study showed that Ni is mainly concentrated in the phloem in roots and stems (up to 16.9% Ni in phloem sap in Phyllanthus balgooyi) in all three species. However, the species differ in their leaves - in P. balgooyi the highest Ni concentration is in the phloem, but in P. securinegioides and R. bengalensis in the epidermis and in the spongy mesophyll (R. bengalensis). The chemical speciation of Ni2+does not substantially differ between the species nor between the plant tissues and transport fluids, and is unambiguously associated with citrate. This study combines ion microbeam (PIXE and RBS) and metabolomics techniques (GC-MS, LC-MS) with synchrotron methods (XAS) to overcome the drawbacks of the individual techniques to quantitatively determine Ni distribution and Ni2+chemical speciation in hyperaccumulator plants.
authors.affiliation: Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Queensland, Australia.|Université de Lorraine-INRA, Laboratoire Sols et Environnement, UMR 1120, France.
authors.forename: Antony
authors.initials: A
authors.lastname: van der Ent
authors.affiliation: Deakin University, Geelong, Australia. School of Life and Environmental Sciences, Centre for Chemistry and Biotechnology (Burwood Campus), Victoria, Australia.
authors.forename: Damien L
authors.initials: DL
authors.lastname: Callahan
authors.affiliation: Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Queensland, Australia.
authors.forename: Barry N
authors.initials: BN
authors.lastname: Noller
authors.affiliation: Materials Research Department, iThemba LABS, National Research Foundation, Somerset West, South Africa.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Mesjasz-Przybylowicz
authors.affiliation: Materials Research Department, iThemba LABS, National Research Foundation, Somerset West, South Africa.|AGH University of Science and Technology, Faculty of Physics &Applied Computer Science, Krakow, Poland.
authors.forename: Wojciech J
authors.initials: WJ
authors.lastname: Przybylowicz
authors.affiliation: Materials Research Department, iThemba LABS, National Research Foundation, Somerset West, South Africa.
authors.forename: Alban
authors.initials: A
authors.lastname: Barnabas
authors.affiliation: Department of Chemistry, The University of Adelaide, South Australia, Australia.
authors.forename: Hugh H
authors.initials: HH
authors.lastname: Harris
mesh_terms: D019684:Magnoliopsida / Q000737:chemistry / Q000378:metabolism*; D008296:Malaysia; D009532:Nickel / Q000032:analysis / Q000378:metabolism*; D052585:Phloem / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism
chemical_list: D009532:Nickel