caa a22 4500 477101984 CHVBK 20180405111544.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF00196573 doi (NATIONALLICENCE)springer-10.1007/BF00196573 Cell divisions in cotyledons after germination: localization, time course and utilization for a mutagenesis assay [Elektronische Daten] [Marcelo Fridlender, Simcha Lev-Yadun, Ivan Baburek, Karel Angelis, Avraham Levy] Post-germinative proliferation of cells was studied in cotyledons of Nicotiana tabacum L., Petunia hybrida Vilm. and Arabidopsis thaliana (L.) Heynh. Patterns of cell divisions after germination were characterized by clonal analysis in cotyledons of N. tabacum. The fate of initial cells, which are formed by the end of embryogenesis, was quite variable: cells could undergo between one to seven, and most often, between three to five anticlinal divisions after germination. Sector shape suggested that there were more divisions in length than in width, particularly at the periphery of the cotyledon. The boundaries of clones generated by irradiation of mature seeds did not intersect the midvein, and in most cases, did not intersect lateral veins. The time course of cell divisions during post-germinative development was analyzed cytologically in cotyledons of N. tabacum and P. hybrida. No divisions were detected up to the second day after sowing (DAS), when the radicle emerged. Cotyledon cells started to divide at a rapid rate between 2 and 3 DAS, reaching a mitotic index of about 2% at 3-4 DAS. A rapid decline followed the peak, and no divisions were detected 6-7 DAS. Similarities between leaf and cotyledon development are discussed. In addition, we show that divisions in cotyledons of N. tabacum and A. thaliana chlorophyll mutants can be exploited for a quick and sensitive bioassay from which the effects of various mutagens and DNA repair genes can be assessed. Springer-Verlag, 1996 Clonal analysis nationallicence Cotyledon development nationallicence Mutations nationallicence Seed germination nationallicence Nicotiana nationallicence DAS : days after sowing nationallicence MMS : methyl methane-sulfonate nationallicence MNU : N-nitrosourea nationallicence Fridlender Marcelo Department of Plant Genetics, The Weizmann Institute of Science, 76100, Rehovot, Israel aut Lev-Yadun Simcha Department of Plant Genetics, The Weizmann Institute of Science, 76100, Rehovot, Israel aut Baburek Ivan Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Na Karlovce 1, 6, Praha, Czech Republic aut Angelis Karel Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Na Karlovce 1, 6, Praha, Czech Republic aut Levy Avraham Department of Plant Genetics, The Weizmann Institute of Science, 76100, Rehovot, Israel aut Planta Springer-Verlag 199/2(1996-06-01), 307-313 0032-0935 199:2<307 1996 199 425 https://doi.org/10.1007/BF00196573 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00196573 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fridlender Marcelo Department of Plant Genetics, The Weizmann Institute of Science, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Lev-Yadun Simcha Department of Plant Genetics, The Weizmann Institute of Science, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Baburek Ivan Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Na Karlovce 1, 6, Praha, Czech Republic aut NATIONALLICENCE 700 1- Angelis Karel Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Na Karlovce 1, 6, Praha, Czech Republic aut NATIONALLICENCE 700 1- Levy Avraham Department of Plant Genetics, The Weizmann Institute of Science, 76100, Rehovot, Israel aut NATIONALLICENCE 773 0- Planta Springer-Verlag 199/2(1996-06-01), 307-313 0032-0935 199:2<307 1996 199 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer