Foliar Application of Iron Fortified Bacteriosiderophore Improves Growth and Grain Fe Concentration in Wheat and Soybean

Abstract

Iron (Fe) is one of the key micronutrients essential for plant growth, yield and quality. Wheat (Triticum aestivum) and soybean (Glycine max) are important food crops but have relatively low Fe content in grains/seeds. Foliar application of Fe-invigorated bacteriosiderophore might increase Fe content in grain as well as improve overall plant growth. From a preliminary experiment conducted on soybean using 20 bacterial strains, Arthrobacter sp. (low siderophore producing) and Lysinibacillus fusiformis (high siderophore producing) were selected based on amount of siderophore produced and response of plants. This result was validated on field grown soybean and wheat crops by applying bacteriosiderophore with or without Fe on foliage. Siderophore was applied at flowering stage in both crops and observations were recorded on the sixth day after foliar spray. Significantly higher shoot biomass, area of leaves or flag leaf and tissue Fe concentration was recorded by siderophore produced by L. fusiformis with Fe as compared to Arthrobacter sp. In comparison to control (water), application of Fe fortified bacterial siderophore resulted not only in increased grain yield by 45% and 28% in wheat and soybean, respectively but also enhanced Fe concentration in grains by 1.7-fold in soybean to 2.0-fold in wheat. Partitioning of Fe in grain was higher in wheat as compared to soybean after foliar spray. Thus, we reported for the first time that bacteriosiderophore with added Fe as foliar application could be an economical and targeted agronomic approach towards Fe fortification in crop plants.