caa a22 4500 477100422 CHVBK 20180405111539.0 cr unu---uuuuu 170330e19961001xx s 000 0 eng 10.1007/BF00208303 doi (NATIONALLICENCE)springer-10.1007/BF00208303 Endo-β-mannanase isoforms are present in the endosperm and embryo of tomato seeds, but are not essentially linked to the completion of germination [Elektronische Daten] [Peter Toorop, J. Bewley, Henk Hilhorst] A current hypothesis is that endo-β-mannanase activity in the endosperm cap of tomato (Lycopersicon esculentum Mill. cv. Moneymaker) seeds is induced by gibberellin (GA) and weakens the endosperm cap thus permitting radicle protrusion. We have tested this hypothesis. In isolated parts, the expression of endo-β-mannanase in the endosperm after germination is induced by GAs, but the expression of endo-β-mannanase in the endosperm cap prior to radicle protrusion is not induced by GAs. Also, abscisic acid (ABA) is incapable of inhibiting endo-β-mannanase activity in the endosperm cap, even though it strongly inhibits germination. However, ABA does inhibit enzyme activity in the endosperm and embryo after germination. There are several isoforms in the endosperm cap and embryo prior to radicle protrusion that are tissue-specific. Tissue prints showed that enzyme activity in the embryo spreads from the radicle tip to the cotyledons with time after the start of imbibition. The isoform and developmental patterns of enzyme activity on tissueprints are unaffected when seeds are incubated in ABA, even though germination is inhibited. We conclude that the presence of endo-β-mannanase activity in the endosperm cap is not in itself sufficient to permit tomato seeds to complete germination. Springer-Verlag, 1996 Abscisic acid nationallicence Endo-β-mannanase isoforms nationallicence Germination (tomato) nationallicence Gibberellin nationallicence Lycopersicon (seeds) nationallicence ABA : cis/trans-abscisic acid nationallicence GA(s) : gibberellin(s) nationallicence IEF : isoelectric focussing nationallicence pI(s) : isoelectric point(s) nationallicence Toorop Peter Department of Plant Physiology, Agricultural University Wageningen, Arboretumlaan 4, NL-6703 BD, Wageningen, The Netherlands aut Bewley J. Department of Botany, University of Guelph, N1G 2W1, Guelph, Ontario, Canada aut Hilhorst Henk Department of Plant Physiology, Agricultural University Wageningen, Arboretumlaan 4, NL-6703 BD, Wageningen, The Netherlands aut Planta Springer-Verlag 200/2(1996-10-01), 153-158 0032-0935 200:2<153 1996 200 425 https://doi.org/10.1007/BF00208303 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00208303 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Toorop Peter Department of Plant Physiology, Agricultural University Wageningen, Arboretumlaan 4, NL-6703 BD, Wageningen, The Netherlands aut NATIONALLICENCE 700 1- Bewley J. Department of Botany, University of Guelph, N1G 2W1, Guelph, Ontario, Canada aut NATIONALLICENCE 700 1- Hilhorst Henk Department of Plant Physiology, Agricultural University Wageningen, Arboretumlaan 4, NL-6703 BD, Wageningen, The Netherlands aut NATIONALLICENCE 773 0- Planta Springer-Verlag 200/2(1996-10-01), 153-158 0032-0935 200:2<153 1996 200 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer