Skip Navigation



JXB Advance Access published online on July 28, 2003
Journal of Experimental Botany, doi:10.1093/jxb/erg233
© 2003 by Oxford University Press
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
54/390/2071    most recent
erg233v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Pérez-Flores, L.
Right arrow Articles by Benech-Arnold, R. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pérez-Flores, L.
Right arrow Articles by Benech-Arnold, R. L.
Agricola
Right arrow Articles by Pérez-Flores, L.
Right arrow Articles by Benech-Arnold, R. L.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Received January 14, 2003; accepted May 29, 2003
© 2003 Society for Experimental Biology

RESEARCH PAPER

Expression analysis of a GA 20-oxidase in embryos from two sorghum lines with contrasting dormancy: possible participation of this gene in the hormonal control of germination

Laura Pérez-Flores 1, Fernando Carrari 2, Reyna Osuna-Fernández 3, M. Verónica Rodríguez 4, Silvina Enciso 4, Roberto Stanelloni 5, Rodolfo A. Sánchez 4, Rubén Bottini 6, Norberto D. Iusem 2, and Roberto L. Benech-Arnold 4*

1 UAM-Iztapalapa, México
2 Laboratorio de Fisiología y Biología Molecular, FCEyN Universidad de Buenos Aires Argentina
3 Facultad de Ciencias, UNAM, México
4 IFEVA-Cátedra de Cerealicultura, Facultad de Agronomía, Universidad de Buenos Aires/CONICET,Av. San Martín 4453, 1417 Buenos Aires, Argentina
5 Instituto de Investigaciones Bioquímicas, Fundación Campomar, Argentina
6 Laboratorio de Fisiología Vegetal, Departamento de Ciencias Naturales, Universidad Nacional de Río Cuarto, Campus Universitario, 5800 Río Cuarto, Argentina

* To whom correspondence should be addressed. E-mail: benech{at}ifeva.edu.ar.


  Abstract

The role of GAs in promoting seed germination is well known and experiments with seeds from different species have suggested the requirement of de novo synthesis of GAs upon imbibition for germination. There are also strong indications that the enhancement of GA synthesis is part of the mechanism through which environmental signals (i.e. light) induce germination. Since along the GA biosynthetic pathway, oxidation at C-20 carried out by GA 20-oxidases is thought to be a site of regulation, a cDNA clone encoding a GA 20-oxidase was isolated from embryos of sorghum (SbGA 20ox). Expression analysis of this gene in embryos within imbibed caryopses with low dormancy showed detectable amounts of the specific mRNA early upon incubation, increasing thereafter. In contrast, it remained barely detectable in embryos from dormant caryopses. Changes in endogenous GA4 levels were in agreement with those of SbGA 20ox mRNA, suggesting that GA production might be regulated differentially at the level of transcription of this gene. The expression of SbGA 20ox was enhanced in incubated embryos isolated from either type of caryopses, illustrating a physiological control exerted by the surrounding seed tissues on gene expression. The results also show that ABA leads to a suppression of transcription of this gene.

Key words: Dormancy, GA 20-oxidase, germination, gibberellins, Sorghum.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Plant Physiol.Home page
D. Reyes, D. Rodriguez, M. P. Gonzalez-Garcia, O. Lorenzo, G. Nicolas, J. L. Garcia-Martinez, and C. Nicolas
Overexpression of a Protein Phosphatase 2C from Beech Seeds in Arabidopsis Shows Phenotypes Related to Abscisic Acid Responses and Gibberellin Biosynthesis
Plant Physiology, August 1, 2006; 141(4): 1414 - 1424.
[Abstract] [Full Text] [PDF]

Home page
 J Exp BotHome page
G. W. Bassel, R. T. Mullen, and J. D. Bewley
ABI3 expression ceases following, but not during, germination of tomato and Arabidopsis seeds
J. Exp. Bot., March 1, 2006; 57(6): 1291 - 1297.
[Abstract] [Full Text] [PDF]

Home page
 J Exp BotHome page
L. Salaita, R. K. Kar, M. Majee, and A. B. Downie
Identification and characterization of mutants capable of rapid seed germination at 10 {degrees}C from activation-tagged lines of Arabidopsis thaliana
J. Exp. Bot., August 1, 2005; 56(418): 2059 - 2069.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.