title: Electron paramagnetic resonance (EPR) spectroscopy characterization of wheat grains from plants of different water stress tolerance.
abstract: Grains of five genotypes of wheat (four Polish and one Finnish), differing in their tolerance to drought stress were chosen for this investigation. Electron paramagnetic resonance spectroscopy allowed observation of transition metal ions (Mn, Fe, Cu) and different types of stable radicals, including semiquinone centers, present in seed coats, as well as several types of carbohydrate radicals found mainly in the inner parts of grains. The content of paramagnetic metal centers was higher in sensitive genotypes (Radunia, Raweta) than in tolerant ones (Parabola, Nawra), whereas the Finnish genotype (Manu) exhibited intermediate amounts. Similarly, the concentrations of both types of radicals, carbohydrates and semiquinone were significantly higher in the grains originating from more sensitive wheat genotypes. The nature of carbohydrate radicals and their concentrations were confronted with the kinds and amounts of sugars found by the biochemical analyses and microscopy observations. It is suggested that some long lived radicals (semiquinone and starch radicals) occurring in grains could be indicators of stress resistance of wheat plants.
authors: Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland. labanows@chemia.uj.edu.pl
authors: Maria
authors: M
authors: Łabanowska
authors: Maria
authors: M
authors: Filek
authors: Magdalena
authors: M
authors: Kurdziel
authors: Elżbieta
authors: E
authors: Bednarska
authors: Aleksandra
authors: A
authors: Dłubacz
authors: Helina
authors: H
authors: Hartikainen
mesh_terms: D000222:Adaptation, Physiological; D016227:Benzoquinones / Q000032:analysis; D015415:Biomarkers; D002241:Carbohydrates / Q000032:analysis; D003300:Copper / Q000032:analysis; D055864:Droughts; D004578:Electron Spin Resonance Spectroscopy; D005387:Finland; D005609:Free Radicals / Q000032:analysis; D014644:Genetic Variation; D005838:Genotype; D007501:Iron / Q000032:analysis; D008345:Manganese / Q000032:analysis; D011044:Poland; D012639:Seeds / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D013312:Stress, Physiological / Q000502:physiology*; D014908:Triticum / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D016227:Benzoquinones; D015415:Biomarkers; D002241:Carbohydrates; D005609:Free Radicals; C025232:semiquinone radicals; D008345:Manganese; D003300:Copper; D007501:Iron