Iron deficiency causes zinc excess in Zea mays

Authors

  • Masatake KANAI,

    1. Department of Applied Biology and Chemistry, Faculty of Applied Bio-Science, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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    • Present address: Department of Cell Biology, National Institute of Basic Biology, Nishigo-naka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan.

    • Masatake Kanai and Midori Hirai have contributed equally to this work.

  • Midori HIRAI,

    1. Department of Applied Biology and Chemistry, Faculty of Applied Bio-Science, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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    • Masatake Kanai and Midori Hirai have contributed equally to this work.

  • Masaaki YOSHIBA,

    1. Department of Applied Biology and Chemistry, Faculty of Applied Bio-Science, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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  • Toshiaki TADANO,

    1. Department of Applied Biology and Chemistry, Faculty of Applied Bio-Science, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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  • Kyoko HIGUCHI

    1. Department of Applied Biology and Chemistry, Faculty of Applied Bio-Science, Tokyo University of Agriculture, Tokyo 156-8502, Japan
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: K. HIGUCHI, Laboratory of Plant Production Chemistry, Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan. Email: khiguchi@nodai.ac.jp

Abstract

Iron deficiency stress causes a severe reduction in plant growth. Although Fe deficiency causes an imbalance in divalent heavy metal nutrients, the mechanisms underlying the growth reduction caused by this imbalance remain unclear. We investigated Zn uptake and accumulation in maize under Fe-deficient conditions. Under Fe-deficient conditions, Zn uptake was 15-fold higher and Zn accumulation was 16-fold higher than that under normal nutrient conditions. The Zn content of maize leaves under Fe-deficient conditions was >0.4 mg g−1 dry weight, which was higher than the content of plants grown in a nutrient solution containing 50 µM ZnCl2. Plant growth under conditions of both Fe and Zn deficiency was significantly higher than that under only Fe-deficient conditions. Moreover, Fe deficiency increased the thiol content of the plant. These results indicate that Fe deficiency causes excess uptake and accumulation of Zn, and that the stress resulting from the Zn overload accelerates growth reduction in maize.

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