title: The effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce somatic embryos.
abstract: Somatic embryogenesis (SE) represents a useful experimental system for studying the regulatory mechanisms of embryo development. In this study, the effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce [Picea abies (L.) Karst] somatic embryos were investigated. Using time lapse photography, we monitored development from proliferation of proembryogenic masses (PEMs) to maturation of somatic embryos in two P. abies cell lines cultured on two maturation treatments. A combination of sugar assays, metabolic and proteomic analyses were used to quantify storage reserves in the mature somatic embryos. The maturation treatment containing a nonpermeating osmoticum, polyethylene glycol (PEG, 7.5%) and maltose (3%) as the carbohydrate gave significantly high maturation and low germination frequencies of somatic embryos compared to the treatment with only 3% sucrose. Somatic embryos treated with 3% sucrose contained high levels of sucrose, raffinose and late embryogenesis abundant (LEA) proteins. These compounds are known to be involved in the acquisition of desiccation tolerance during seed development and maturation. In addition the sucrose treatment significantly increased the content of starch in the somatic embryos while the maltose and PEG treatment resulted in somatic embryos with a high content of storage proteins. The high levels of sucrose, raffinose and LEA proteins in the embryos treated with 3% sucrose suggest that sucrose may improve the germination of somatic embryos by promoting the acquisition of desiccation tolerance.
authors: Department of Forest Genetics and Plant Physiology, Umeå Plant Science Center, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden.
authors: Edward
authors: E
authors: Businge
authors: Joakim
authors: J
authors: Bygdell
authors: Gunnar
authors: G
authors: Wingsle
authors: Thomas
authors: T
authors: Moritz
authors: Ulrika
authors: U
authors: Egertsdotter
mesh_terms: D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D018525:Germination / Q000187:drug effects*; D008320:Maltose / Q000378:metabolism / Q000494:pharmacology*; D055432:Metabolomics / Q000379:methods; D015999:Multivariate Analysis; D009664:Norway; D009997:Osmotic Pressure; D028222:Picea / Q000166:cytology / Q000196:embryology*; D010940:Plant Proteins / Q000378:metabolism; D058439:Plant Somatic Embryogenesis Techniques / Q000379:methods; D011092:Polyethylene Glycols / Q000378:metabolism / Q000494:pharmacology; D025341:Principal Component Analysis; D011887:Raffinose / Q000378:metabolism; D012639:Seeds / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013213:Starch / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D010940:Plant Proteins; D011092:Polyethylene Glycols; D013395:Sucrose; D008320:Maltose; D013213:Starch; D011887:Raffinose