title: Comparative quantitative proteomic analysis of embryogenic and non-embryogenic calli in maize suggests the role of oxylipins in plant totipotency.
abstract: Totipotency, the ability of somatic plant cell to generate whole plant through somatic embryogenesis, is still not well understood. In this study, maize immature zygotic embryos were used to generate embryogenic (EC) and non-embryogenic (NEC) calli. In order to compare proteomes of EC and NEC, two-dimensional electrophoresis (2-DE) in combination with mass spectrometry was used. This approach resulted into 361 quantified 2-DE spots out of which 44 were found statistically significantly differentially abundant between EC and NEC. Mass spectrometry provided the identity for 23 proteins that were classified into 8 metabolic categories. The most abundant were proteins associated with energy followed by proteins associated with disease and defense. Based on the abundances of identified proteins in this and other studies, working model for plant totipotency was proposed. One aspect of this working model suggests that increased abundances of proteins associated with pyruvate biosynthesis and suppression of embryogenic genes might be responsible for differences between EC and NEC cells. Furthermore we speculate that the increased abundance of lipoxygenase in the NEC cells results in changes in the equilibrium levels of one or more signaling molecules and is at least partly responsible for somatic cell reprogramming during totipotency.
  
  
  CONCLUSIONS
  Totipotency, the ability of somatic plant cell to generate whole plant through somatic embryogenesis, is still not well understood. In order to further advance understanding of this biological phenomenon, proteomes of embryogenic and non-embryogenic callus, derived from immature zygotic embryos of inbred maize line A19, were compared using 2-DE based proteomic technology. Based on the abundances of identified proteins in this and other studies, working model for plant totipotency was proposed. One aspect of this working model suggests that increased abundances of proteins associated with pyruvate biosynthesis and suppression of embryogenic genes might be responsible for differences between EC and NEC cells. Furthermore we speculate that the increased abundance of lipoxygenase in the NEC cells results in changes in the equilibrium levels of one or more signaling molecules and is at least partly responsible for somatic cell reprogramming during totipotency. This article is part of a Special Issue entitled: Environmental and structural proteomics.
authors: Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia.
authors: Miroslava
authors: M
authors: Varhaníková
authors: Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia.
authors: Lubica
authors: L
authors: Uvackova
authors: Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia; Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors: Ludovit
authors: L
authors: Skultety
authors: Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia; University of Cyril and Method, Trnava, Slovakia.
authors: Anna
authors: A
authors: Pretova
authors: Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia.
authors: Bohuš
authors: B
authors: Obert
authors: Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia; Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia. Electronic address: hajduch@savba.sk.
authors: Martin
authors: M
authors: Hajduch
mesh_terms: D047108:Embryonic Development / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D020543:Proteome / Q000378:metabolism; D012639:Seeds / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D039901:Totipotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D003313:Zea mays / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*
chemical_list: D054883:Oxylipins; D010940:Plant Proteins; D020543:Proteome
keywords: 2-DE; Embryogenic genes; Lipoxygenase; MS(E); Model; Pyruvate