20-21 November 2014
National Centre for Synchrotron Science
Australia/Melbourne timezone
Save the date: User Meeting 2015 - 26-27 November

Distribution of aluminium in plant roots: Understanding its toxicity through correlative microscopy

21 Nov 2014, 13:45
30m
NCSS Seminar Room ()

NCSS Seminar Room

Oral Earth and Environment Earth and Environment

Speaker

Dr Peter Kopittke (The University of Queensland)

Description

Aluminium (Al) is toxic to plant root growth in the acid soils comprising ca. 40-70% of the world’s arable land, but the mechanisms whereby Al reduces growth remain unclear. Despite 30 µM Al decreasing root growth within 30 min, we are unaware of any study that has provided information on the distribution of Al in roots within this timeframe. Using roots of soybean (Glycine max (L.) Merr.) exposed to 30 µM Al, we identified and separated individual mechanisms of toxicity through the use of high resolution kinematic analyses together with the complementary use of synchrotron-based low-energy X-ray fluorescence spectromicroscopy (LEXRFS) and nano secondary ion mass spectroscopy (nanoSIMS). The latter techniques revealed the majority of Al to be located in the outer cellular layers within 30 min of exposure, decreasing markedly with increasing distance from the root surface. At the sub-cellular level, the majority of the Al was found to accumulate in the cell wall. Of particular importance, Al was bound strongly by (i) pectin in the corner junctions between cells, with this typically the location where Al first accumulated in the inner tissues, (ii) walls of the border cells (c.f. the walls of the adjacent rhizodermal cells), and (iii) the mucigel on the root surface. For the first time, correlative microscopy (LEXAFS and nanoSIMS) and other complementary techniques have provided important evidence as to where Al accumulates in the short term and how Al rapidly reduces the growth of plant roots.
Keywords or phrases (comma separated) Correlative microscopy, Metal toxicity, Plant roots

Primary author

Dr Peter Kopittke (The University of Queensland)

Co-authors

Dr Alessandra Gianoncelli (Synchrotron Radiation Facility, Elettra Sincrotrone, Trieste-Basovizza, Italy) Prof. Enzo Lombi (University of South Australia, Centre for Environmental Risk Assessment and Remediation, Mawson Lakes, South Australia, 5095, Australia) Dr Katie Moore (University of Oxford, Department of Materials, Oxford, OX1 3PH, United Kingdom) Prof. Neal Menzies (The University of Queensland, School of Agriculture and Food Sciences, St. Lucia, Queensland, 4072, Australia) Prof. Pax Blamey (The University of Queensland, School of Agriculture and Food Sciences, St. Lucia, Queensland, 4072, Australia)

Presentation Materials

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