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J Plant Growth Regul (2012) 31:498508 DOI 10.1007/s00344-012-9259-7
Synthesis of Iron-Amino Acid Chelates and Evaluation of Their Efcacy as Iron Source and Growth Stimulator for Tomatoin Nutrient Solution Culture
Somayeh Ghasemi Amir H. Khoshgoftarmanesh
Hassan Hadadzadeh Mehran Jafari
Received: 12 November 2011 / Accepted: 22 December 2011 / Published online: 2 February 2012 Springer Science+Business Media, LLC 2012
Abstract Supplying a sufcient amount of available iron (Fe) for plant growth in hydroponic nutrient solutions is a great challenge. The chelators commonly used to supply Fe in nutrient solutions have several disadvantages and may negatively affect plant growth. In this research study we have synthesized certain Fe-amino acid chelates, including Fe-arginine [Fe(Arg)2], Fe-glycine [Fe(Gly)2], and Fe-histidine [Fe(His)2], and evaluated their efcacy as an Fe source for two tomato cultivars (Lycopersicon esculentum
Mill. cvs. Rani and Sarika) grown in nutrient solution.
Application of Fe-amino acid chelates signicantly increased root and shoot dry matter yield of both tomato cultivars compared with Fe-EDTA. Tomato plants supplied with Fe-amino acid chelates also accumulated signicantly higher levels of Fe, Zn, and N in their roots and shoots compared with those supplied with Fe-EDTA. In Sarika, the effect of Fe-amino acid chelates on shoot Fe content was in the order Fe(His)2 [ Fe(Gly)2 [ Fe(Arg)2. In Rani, the addition of all synthesized Fe-amino acid chelates signicantly increased activity of ascorbate peroxidase (APX) in comparison with Fe-EDTA, whereas in Sarika, only Fe(His)2 increased shoot APX activity. The results obtained indicated that using Fe-amino acid chelates
in the nutrient solution could supply a sufcient amount of Fe for plant uptake and also improve root and shoot growth of tomato plants, although this increase was cultivar-dependent. According to the results, Fe-amino acid chelates can be used as an alternative for Fe-EDTA to supply Fe in nutrient solutions.
Keywords Amino acids Chelate Fe availability
Fe-EDTA Tomato
Introduction
Iron (Fe) is an important micronutrient that plays a role in several crop physiological processes such as photosynthesis, respiration, and synthesis of heme proteins, DNA, RNA, and hormones (Curie and others 2009; Rivero and others 2003). In nutrient solution cultures, synthetic Fe chelates are widely used to maintain a desirable concentration of this element for the plant (Parker and Norvell 1999; Vadas and others 2007). The most common...