title: Nuclear magnetic resonance metabolomics of iron deficiency in soybean leaves.
abstract: Iron (Fe) deficiency is an important agricultural concern that leads to lower yields and crop quality. A better understanding of the condition at the metabolome level could contribute to the design of strategies to ameliorate Fe-deficiency problems. Fe-sufficient and Fe-deficient soybean leaf extracts and whole leaves were analyzed by liquid (1)H nuclear magnetic resonance (NMR) and high-resolution magic-angle spinning NMR spectroscopy, respectively. Overall, 30 compounds were measurable and identifiable (comprising amino and organic acids, fatty acids, carbohydrates, alcohols, polyphenols, and others), along with 22 additional spin systems (still unassigned). Thus, metabolite differences between treatment conditions could be evaluated for different compound families simultaneously. Statistically relevant metabolite changes upon Fe deficiency included higher levels of alanine, asparagine/aspartate, threonine, valine, GABA, acetate, choline, ethanolamine, hypoxanthine, trigonelline, and polyphenols and lower levels of citrate, malate, ethanol, methanol, chlorogenate, and 3-methyl-2-oxovalerate. The data indicate that the main metabolic impacts of Fe deficiency in soybean include enhanced tricarboxylic acid cycle activity, enhanced activation of oxidative stress protection mechanisms and enhanced amino acid accumulation. Metabolites showing accumulation differences in Fe-starved but visually asymptomatic leaves could serve as biomarkers for early detection of Fe-deficiency stress.
authors.affiliation: CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto , Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: Marta R M
authors.initials: MR
authors.lastname: Lima
authors.forename: Sílvia O
authors.initials: SO
authors.lastname: Diaz
authors.forename: Inês
authors.initials: I
authors.lastname: Lamego
authors.forename: Michael A
authors.initials: MA
authors.lastname: Grusak
authors.forename: Marta W
authors.initials: MW
authors.lastname: Vasconcelos
authors.forename: Ana M
authors.initials: AM
authors.lastname: Gil
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D055442:Metabolome; D055432:Metabolomics; D015999:Multivariate Analysis; D018384:Oxidative Stress; D010936:Plant Extracts / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D013025:Glycine max / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D010936:Plant Extracts; D007501:Iron