Brassinosteroid levels increase drastically prior to morphogenesis of tracheary elements

Citation
R. Yamamoto et al., Brassinosteroid levels increase drastically prior to morphogenesis of tracheary elements, PLANT PHYSL, 125(2), 2001, pp. 556-563
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT PHYSIOLOGY
ISSN journal
0032-0889 → ACNP
Volume
125
Issue
2
Year of publication
2001
Pages
556 - 563
Database
ISI
SICI code
0032-0889(200102)125:2<556:BLIDPT>2.0.ZU;2-1
Abstract
As the first step toward understanding the involvement of endogenous brassi nosteroids (BRs) in cytodifferentiation, we analyzed biosynthetic activitie s of BRs in zinnia (Zinnia elegans L. cv Canary Bird) cells differentiating into tracheary elements. The results of feeding experiments suggested that both the early and late C6-oxidation pathways occur during tracheary eleme nt differentiation. Gas chromatography-mass spectrometry analysis revealed that five BRs, castasterone, typhasterol, 6-deoxocastasterone, 6-deoxotypha sterol, and 6-deoxoteasterone, actually existed in cultured zinnia cells an d culture medium. Quantification of endogenous BRs in each stage of trachea ry element differentiation by gas chromatography-mass spectrometry exhibite d that they increased dramatically prior to the morphogenesis, which was co nsistent with the idea that BRs are necessary for the initiation of the fin al stage of tracheary element differentiation. Moreover, the proportion of each BR in culture medium was quite different from that in cells, suggestin g that specific BRs are selectively secreted into medium and may function o utside the cells.