title: In situ localisation of cytokinins in the shoot apical meristem of Sinapis alba at floral transition.
abstract: In plants of Sinapis alba L. induced to flower by one long day (LD), previous work showed that the phloem sap feeding the shoot apex is enriched in cytokinins of the isopentenyladenine (iP)-type between 9 and 25 h after start of the LD [P. Lejeune et al. (1994) Physiol Plant 90:522-528]. We have checked the hypothesis that the cytokinin content of the shoot apical meristem (SAM) should increase in response to floral induction by one LD using histoimmunolocalisation techniques and rabbit antiserum against isopentenyladenosine or zeatin riboside. The free bases iP and zeatin are present only in apical tissues containing dividing cells. At 30 h after the start of an inductive LD, a markedly increased iP immune reaction is observed in SAM tissues while the level of zeatin is not modified. Our results are in line with the data obtained by analysis of phloem sap.
authors.affiliation: Laboratoire de Physiologie Végétale, Département des sciences de la vie, Institut de Botanique, Université de Liège, Sart Tilman, 4000, Belgium. annie.jacqmard@ulg.ac.be
authors.forename: Annie
authors.initials: A
authors.lastname: Jacqmard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Detry
authors.forename: Walter
authors.initials: W
authors.lastname: Dewitte
authors.forename: Harry
authors.initials: H
authors.lastname: Van Onckelen
authors.forename: Georges
authors.initials: G
authors.lastname: Bernier
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000032:analysis; D000818:Animals; D003583:Cytokinins / Q000032:analysis*; D007150:Immunohistochemistry; D007541:Isopentenyladenosine; D018519:Meristem / Q000737:chemistry* / Q000528:radiation effects; D009149:Mustard Plant / Q000737:chemistry* / Q000528:radiation effects; D017440:Photoperiod; D018520:Plant Shoots / Q000737:chemistry* / Q000528:radiation effects; D011817:Rabbits; D012098:Reproduction; D015026:Zeatin / Q000032:analysis
chemical_list: D003583:Cytokinins; C001478:N(6)-(delta(2)-isopentenyl)adenine; D007541:Isopentenyladenosine; D015026:Zeatin; D000225:Adenine