Development of a mugineic acid family phytosiderophores analog “PDMA” as an iron fertilizer

Abstract

Iron (Fe) is an essential nutrient for plant growth. Fe deficiency occurs frequently in alkaline or calcareous soils because of low solubility of Fe under high pH. Poaceae plants take up Fe(III) complex with mugineic acid family phytosiderophores (MAs) after their secretion. Insufficient secretion of MAs causes Fe deficiency and reduction of crop production. Application of 2’-deoxymugineic acid (DMA) into soil recovered Fe deficiency in rice plants, but the effect was not prolonged because of high biodegradability of DMA. Here, we developed a novel analog of phytosiderophore designated “proline 2’-deoxymugineic acid (PDMA)” by chemical synthesis. Soil application of Fe-PDMA or metal-free PDMA recovered Fe deficiency in rice plants. The effect of soil-applied Fe-PDMA was sustained longer than that of Fe-DMA. In addition, soil application of Fe-PDMA to non-poaceae plants also resulted in better recovery from Fe deficiency compared to other chelating complexes. The reducibility of Fe(III)-PDMA to ferrous ion was higher than that of other chelating complexes. The efficacy of PDMA was demonstrated in rice and peanuts in field experiments. In summary, PDMA is a promising chelate as a fertilizer not only for poaceae plants but also for non-poaceae plants, and its moderate biodegradability might be compatible with environment.