caa a22 4500 477100082 CHVBK 20180405111538.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF00196662 doi (NATIONALLICENCE)springer-10.1007/BF00196662 Stress as the major signal controlling the developmental fate of tobacco microspores: towards a unified model of induction of microspore/pollen embryogenesis [Elektronische Daten] [A. Touraev, M. Pfosser, O. Vicente, E. Heberle-Bors] Specific stress treatments (sucrose starvation, alone or combined with a heat shock) applied to isolated tobacco (Nicotiana tabacum L.) microspores irreversibly blocked normal gametophytic development and induced the formation of embryogenic cells, which developed subsequently into pollen-derived embryos by culture at 25°C in a sugar-containing medium. A cold shock at 4°C did not inhibit microspore maturation in vitro and did not induce cell division activity, even when combined with a starvation treatment. In the absence of sucrose, microspores isolated in the G1 phase of the cell cycle replicated their DNA and accumulated in G2. Late microspores underwent miotosis during the first day of culture which resulted in a mixed population of bicellular pollen grains and uninucleate microspores, both embryogenic. After the inductive stress treatments the origin of the first multicellular structures, formed in the sugar-containing medium, could be traced to divisions of the microspore cell or divisions of the vegetative cell of bicellular pollen, indicating that the symmetry of microspore mitosis in vitro is not important for embryogenic induction. These results represent a step forward towards a unified model of induction of embryogenesis from microspores/pollen which, within a relatively wide developmental window, are competent to deviate from normal gametophytic development and initiate the alternative sporophytic programme, in response to specific stress signals. Springer-Verlag, 1996 Heat shock nationallicence Microspore embryogenesis nationallicence Nicotiana nationallicence Pollen development nationallicence Starvation nationallicence Stress nationallicence DAPI : 4,6-diamidino-2-phenylindole nationallicence Touraev A. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut Pfosser M. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut Vicente O. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut Heberle-Bors E. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut Planta Springer-Verlag 200/1(1996-09-01), 144-152 0032-0935 200:1<144 1996 200 425 https://doi.org/10.1007/BF00196662 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00196662 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Touraev A. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut NATIONALLICENCE 700 1- Pfosser M. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut NATIONALLICENCE 700 1- Vicente O. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut NATIONALLICENCE 700 1- Heberle-Bors E. Vienna Biocenter, Institute of Microbiology and Genetics, University of Vienna, Dr. Bohr-Gasse 9, A-1030, Vienna, Austria aut NATIONALLICENCE 773 0- Planta Springer-Verlag 200/1(1996-09-01), 144-152 0032-0935 200:1<144 1996 200 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer