title: Enhanced levels of nicotianamine promote iron accumulation and tolerance to calcareous soil in soybean.
abstract: Iron (Fe) is an essential nutrient in both plants and humans. Fe deficiency on calcareous soil with low Fe availability is a major agricultural problem. Nicotianamine (NA) is one of the Fe chelator in plants, which is involved in metal translocation into seeds, and serves as an antihypertensive substance in humans. In this study, soybean plants overexpressing the barley NA synthase 1 (HvNAS1) gene driven by the constitutive CaMV 35S promoter were produced using Agrobacterium-mediated transformation. The transgenic soybean showed no growth defect and grew normally. The NA content of transgenic soybean seeds was up to four-fold greater than that of non-transgenic (NT) soybean seeds. The level of HvNAS1 expression was positively correlated with the amount of NA, and a high concentration of NA was maintained in the seeds in succeeding generations. The Fe concentration was approximately two-fold greater in transgenic soybean seeds than in NT soybean seeds. Furthermore, the transgenic soybeans showed tolerance to low Fe availability in calcareous soil. Our results suggested that increasing the NA content in soybean seeds by the overexpression of HvNAS1 offers potential benefits for both human health and agricultural productivity.
authors.affiliation: a Department of Global Agricultural Sciences , Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo , Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nozoye
authors.forename: Suyoen
authors.initials: S
authors.lastname: Kim
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kakei
authors.forename: Michiko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nakanishi
authors.forename: Naoko K
authors.initials: NK
authors.lastname: Nishizawa
mesh_terms: D060054:Agrobacterium / Q000235:genetics; D019883:Alkyl and Aryl Transferases / Q000235:genetics; D001383:Azetidinecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002119:Calcium Carbonate / Q000032:analysis*; D001467:Hordeum / Q000235:genetics; D007501:Iron / Q000032:analysis / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics; D012987:Soil / Q000737:chemistry*; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D014170:Transformation, Genetic; D015032:Zinc / Q000378:metabolism
chemical_list: D012987:Soil; C082893:nicotianamine; D001383:Azetidinecarboxylic Acid; D007501:Iron; D019883:Alkyl and Aryl Transferases; C118230:nicotianamine synthase; D002119:Calcium Carbonate; D015032:Zinc
keywords: calcareous soil; iron (Fe); nicotianamine (NA); soybean; transformation