Title : Evaluation of the capacity of tris(3-hydroxy-4-pyridinonate) iron(III) complexes to correct iron deficiency chlorosis in soybean (Glycine max L.)
Abstract:
Successful cultivation of crops with the best nutritional properties is an issue of paramount importance in the Agricultural and Health fields. Iron (Fe) is an essential nutrient for plants and legumes are one of the major sources of Fe in human diet. However the absorption of Fe by the roots of plants is compromised when grown in alkaline soil. As a consequence, plants may suffer from Iron Deficiency Chlorosis (IDC), characterized by chlorosis, yield losses, and lower concentrations of Fe in edible parts of the plant.
To address IDC, farmers must rely on supplementing their crops with Fe-chelates to avoid serious growth deficiencies. Compounds Fe-EDTA and Fe-EDDHA, are commercial products used in agricultural context and some drawbacks have already been reported. The limited number of distinct Fe chelates that are used as fertilizers calls for the identification of new ligands capable of producing Fe-complexes with properties that allow more efficient pathways for root uptake, root to shoot translocation and maintenance of metal homeostasis.
We considered that 3-hydroxy-4-pyridinones were eligible to formulate new Fe fertilizers and herein we report a study regarding the hydroponic growth of soybean (Glycine max L.) in which we tested two 3,4-HPO Fe-chelates in comparison with the commercial fertilizer Fe-EDDHA. Chlorosis development was assessed using SPAD measurements and total chlorophyll quantification. The amount of Fe was quantified in roots and leaves, using atomic absorption spectroscopy.
We found that 3,4-HPO Fe-chelates have great potential as new IDC correctors since plants were significantly greener and had increased biomass. In particular, plants supplied with one of the compounds, were able to translocate more iron from the roots to the shoots not eliciting the expression of the Fe stress related genes. The results suggest that 3,4-HPO Fe-chelates could be economically and environmentally favourable in agricultural contexts.
This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia), under the Partnership Agreement PT2020 through project UID/QUI/50006/2019 (LAQV/REQUIMTE) and PTDC/AGRPRO/3515/2014-POCI-01-0145-FEDER-016599.
