18th International Symposium on Iron Nutrition and Interaction in Plants
Madrid – May 30-June 3 2016
ELEVATED CARBON DIOXIDE CONCENTRATION DECREASES IRON UPTAKE AND
INCREASES IRON REMOBILISATION TO LEAVES IN WHEAT DURING GRAIN
FILLING.
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Marianne Weisser *, Michael Tausz , José T. Sánchez-Palacios , Ute Roessner ,Glen J. Fitzgerald ,
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Alexander A. T. Johnson
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School of BioSciences, The University of Melbourne, Victoria 3010, Australia.
School of Ecosystem and Forest Sciences, The University of Melbourne, Victoria 3363, Australia.
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Agriculture Victoria, Horsham Victoria, Australia.
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Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3363, Australia.
*[email protected]
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Increased levels of atmospheric carbon dioxide (CO2) concentration have been shown to reduce the
concentration of iron (Fe) in bread wheat grain (Triticum aestivum) [1,2], yet the biological factors responsible
for this reduction are currently unknown. The aim of this study is to determine whether changes in Fe uptake,
translocation and/or remobilisation in wheat are responsible for decreased grain Fe concentrations under
CO2 enrichment. Field trials were conducted over two years (2013 and 2015) at the Australian Grain Free Air
Carbon Dioxide Enrichment (AGFACE) facility. Bread wheat cv. Yitpi was grown under ambient CO2 (aCO2;
390 ppm) and elevated CO2 conditions (eCO2; 550 ppm). Iron partitioning analysis of plants grown in the
2013 field trial showed an increase in allocation to all leaves by 9% and bracts by 6% and a decrease to
grain by 9% during grain filling under eCO2. Iron uptake and remobilization per total plant was found to be
similar for both CO2 treatments throughout the growth cycle until grain filling, when a decrease of 50% and
14% in iron uptake and remobilization, respectively, was found under eCO2. The 2013 data suggests that
reduced Fe concentrations in wheat grain under eCO2 can be attributed to increased Fe allocation to the
leaves, flag leaves and bracts at the expense of grain; as well as decreased Fe uptake from soil, during grain
filling. The Fe partitioning analysis of plants grown in the 2015 field trial are currently under way and results
to date will be presented.
Keywords: Elevated carbon dioxide, iron-uptake, iron-remobilisation, iron-partitioning, bread wheat.
REFERENCES:
[1] Högy and Fangmeier 2008 J. Cereal Sci 48(3):580-91
[2] Myers et al. 2014 Nature, 510(7503), pp.139-142
ACKNOWLEDGEMENT:
This research was supported by grants from the HarvestPlus Challenge Program and the Australian Grain
Free Air CO2 Enrichment (AGFACE) program. AGFACE is jointly run by The University of Melbourne and
Agriculture Victoria, and receives funding from the Australian Department of Agriculture and Water
Resources and the Grains Research and Development Corporation.
Preferred presentation format:
Oral
Selected session:
Iron interaction with the environment.
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