title: A possible biochemical basis for fructose-induced inhibition of embryo development in Norway spruce (Picea abies).
abstract: Sugars play an important role in various physiological processes during plant growth and development; however, the developmental roles and regulatory functions of hexoses other than glucose are still largely unclear. Recent studies suggest that blocked embryo development in Norway spruce (Picea abies (L.) Karst) is associated with accumulation of fructose. In the present study, the potential biochemical regulatory mechanism of glucose and fructose was studied during development of somatic embryos of Norway spruce from pro-embryogenic masses to mature embryos. The changes in protein fluorescence, a marker of the Maillard reaction, were monitored in two cell lines of Norway spruce that were grown on media containing sucrose (control), glucose or fructose. Manual time-lapse photography showed that growth of embryogenic cultures on medium containing sucrose was characterized by normal development of mature embryos whereas the embryogenic cultures that were grown on media containing glucose or fructose did not develop mature embryos. The biochemical analyses of embryogenic samples collected during embryo development showed that: (i) the content of glucose and fructose in the embryogenic cultures increased significantly during growth on each medium, respectively; (ii) the accumulation of Maillard products in the embryogenic cultures was highly correlated with the endogenous content of fructose but not glucose; and (iii) the embryogenic cultures grown on fructose displayed the highest protein carbonyl content and DNA damage whereas the highest content of glutathione was recorded in the embryogenic cultures that had grown on sucrose. Our data suggest that blocked development of embryos in the presence of fructose may be associated with the Maillard reaction.
authors.affiliation: Department of Forest Genetics and Plant Physiology, Umeå Plant Science Center, University of Agricultural Sciences, 901 83 Umeå, Sweden.
authors.forename: Edward
authors.initials: E
authors.lastname: Businge
authors.affiliation: Department of Forest Genetics and Plant Physiology, Umeå Plant Science Center, University of Agricultural Sciences, 901 83 Umeå, Sweden G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 500 Tenth Street NW, Atlanta, GA 30332-0620, USA ulrika.egertsdotter@slu.se.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Egertsdotter
mesh_terms: D004249:DNA Damage / Q000187:drug effects; D005632:Fructose / Q000378:metabolism / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D015416:Maillard Reaction / Q000187:drug effects; D028222:Picea / Q000187:drug effects / Q000196:embryology / Q000254:growth & development / Q000502:physiology*; D058439:Plant Somatic Embryogenesis Techniques; D050050:Protein Carbonylation / Q000187:drug effects; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology; D059008:Time-Lapse Imaging
chemical_list: D005632:Fructose; D013395:Sucrose; D005978:Glutathione; D005947:Glucose
keywords: DNA damage; Maillard reaction; protein carbonyl content; reducing sugars; somatic embryogenesis