Ethylene-responsive element binding protein (EREBP) expression and the transcriptional regulation of class I beta-1,3-glucanase during tobacco seed germination

Citation
G. Leubner-metzger et al., Ethylene-responsive element binding protein (EREBP) expression and the transcriptional regulation of class I beta-1,3-glucanase during tobacco seed germination, PLANT MOL B, 38(5), 1998, pp. 785-795
Citations number
46
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT MOLECULAR BIOLOGY
ISSN journal
0167-4412 → ACNP
Volume
38
Issue
5
Year of publication
1998
Pages
785 - 795
Database
ISI
SICI code
0167-4412(199811)38:5<785:EEBP(E>2.0.ZU;2-4
Abstract
Class I beta-1,3-glucanase (beta GLU I) is transcriptionally induced in the micropylar endosperm just before its rupture prior to the germination (i.e . radicle emergence) of Nicotiana tabacum L. cv. 'Havana 425' seeds. Ethyle ne is involved in endosperm rupture and high-level beta GLU I expression; b ut, it does not affect the spatial and temporal pattern of beta GLU I expre ssion. A promoter deletion analysis of the tobacco beta GLU I B gene sugges ts that (1) the distal -1452 to -1193 region, which contains the positively acting ethylene-responsive element (ERE), is required for high-level, ethy lene-sensitive expression, (2) the regions - 1452 to -1193 and -402 to 0 co ntribute to downregulation by abscisic acid (ABA), and (3) the region -402 to -211 is necessary and sufficient for low-level micropylar-endosperm-spec ific expression. Transcripts of the ERE-binding proteins (EREBPs) showed a novel pattern of expression during seed germination: light or gibberellin w as required for EREBP-3 and EREBP-4 expression; EREBP-4 expression was cons titutive and unaffected by ABA or ethylene; EREBP-3 showed transient induct ion just before endosperm rupture, which was earlier in ethylene-treated se eds and inhibited by ABA. No expression of EREBP-1 and EREBP-2 was detected . In contrast to beta GLU I, EREBP-3 and EREBP-4 were not expressed specifi cally in the micropylar endospenn. The results suggest that transcriptional regulation of beta GLU I could depend on: activation of ethylene signallin g pathways acting via EREBP-3 with the ERE as the target, and ethylene-inde pendent signalling pathways with targets in the proximal promoter region th at are likely to determine spatial and temporal patterns of expression.