title: Localization of aluminium in tea (Camellia sinensis) leaves using low energy X-ray fluorescence spectro-microscopy.
abstract: Information on localization of Al in tea leaf tissues is required in order to better understand Al tolerance mechanism in this Al-accumulating plant species. Here, we have used low-energy X-ray fluorescence spectro-microscopy (LEXRF) to study localization of Al and other low Z-elements, namely C, O, Mg, Si and P, in fully developed leaves of the tea plant [Camellia sinensis (L.) O. Kuntze]. Plants were grown from seeds for 3 months in a hydroponic solution, and then exposed to 200 microM AlCl(3) for 2 weeks. Epidermal-mesophyll and xylem phloem regions of 20 microm thick cryo-fixed freeze-dried tea-leaf cross-sections were raster scanned with 1.7 and 2.2 keV excitation energies to reach the Al-K and P-K absorption edges. Al was mainly localized in the cell walls of the leaf epidermal cells, while almost no Al signal was obtained from the leaf symplast. The results suggest that the retention of Al in epidermal leaf apoplast represent the main tolerance mechanism to Al in tea plants. In addition LEXRF proved to be a powerful tool for localization of Al in plant tissues, which can help in our understanding of the processes of Al uptake, transport and tolerance in plants.
authors.affiliation: Laboratorio de Fisiología Vegetal, Facultad de Biociencias, Universidad Autónoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Roser
authors.initials: R
authors.lastname: Tolrà
authors.forename: Katarina
authors.initials: K
authors.lastname: Vogel-Mikuš
authors.forename: Roghieh
authors.initials: R
authors.lastname: Hajiboland
authors.forename: Peter
authors.initials: P
authors.lastname: Kump
authors.forename: Paula
authors.initials: P
authors.lastname: Pongrac
authors.forename: Burkhard
authors.initials: B
authors.lastname: Kaulich
authors.forename: Alessandra
authors.initials: A
authors.lastname: Gianoncelli
authors.forename: Vladimir
authors.initials: V
authors.lastname: Babin
authors.forename: Juan
authors.initials: J
authors.lastname: Barceló
authors.forename: Marjana
authors.initials: M
authors.lastname: Regvar
authors.forename: Charlotte
authors.initials: C
authors.lastname: Poschenrieder
mesh_terms: D000535:Aluminum / Q000378:metabolism*; D028241:Camellia sinensis / Q000166:cytology / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000379:methods*; D052585:Phloem / Q000166:cytology; D019441:Plant Epidermis / Q000166:cytology / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism*; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D052584:Xylem / Q000166:cytology
chemical_list: D000535:Aluminum