Development of a mugineic acid family phytosiderophore analog as an iron fertilizer

Iron (Fe) is an essential nutrient, but is poorly bioavailable because of its low solubility in alkaline soils; this leads to reduced agricultural productivity. To overcome this problem, we first showed that the soil application of synthetic 2'-deoxymugineic acid, a natural phytosiderophore from the Poaceae, can recover Fe deficiency in rice grown in calcareous soil. However, the high cost and poor stability of synthetic 2'-deoxymugineic acid preclude its agricultural use. In this work, we develop a more stable and less expensive analog, proline-2'-deoxymugineic acid, and demonstrate its practical synthesis and transport of its Fe-chelated form across the plasma membrane by Fe(III) 2'-deoxymugineic acid transporters. Possibility of its use as an iron fertilizer on alkaline soils is supported by promotion of rice growth in a calcareous soil by soil application of metal free proline-2'-deoxymugineic acid.

Motofumi Suzuki, Atsumi Urabe, Sayaka Sasaki, Ryo Tsugawa, Satoshi Nishio, Haruka Mukaiyama, Yoshiko Murata, Hiroshi Masuda, May Sann Aung, Akane Mera, Masaki Takeuchi, Keijo Fukushima, Michika Kanaka, Kaori Kobayashi, Yuichi Chiba, Binod Babu Shrestha, Hiromi Nakanishi, Takehiro Watanabe, Atsushi Nakayama, Hiromichi Fujino, Takanori Kobayashi, Keiji Tanino, Naoko K. Nishizawa, Kosuke Namba