First published online July 6, 2007; 10.1104/pp.107.100560
Plant Physiology 145:87-97 (2007)
© 2007 American Society of Plant Biologists
DEVELOPMENT AND HORMONE ACTION
A Putative Hydroxysteroid Dehydrogenase Involved in Regulating Plant Growth and Development1
Fengling Li2,
Tadao Asami,
Xianzhong Wu2,
Edward W.T. Tsang and
Adrian J. Cutler*
Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Canada S7N 0W9 (F.L., X.W., E.W.T.T., A.J.C.); and Plant Functions Lab, Institute of Physical and Chemical Research, 2–1 Hirosawa, Wako, Saitama 351–0198, Japan (T.A.)
We have functionally characterized an Arabidopsis (Arabidopsis thaliana) gene AtHSD1 (At5g50600) that encodes a protein with homology to animal 11- -hydroxysteroid dehydrogenase (HSD). Transgenic Arabidopsis plants overexpressing AtHSD1 (designated AOHSD plants) under the control of the cauliflower mosaic virus 35S promoter showed increased growth and seed yield as well as increased tolerance of saline stress and reduced seed dormancy. In canola (Brassica napus), transgenic plants overexpressing AtHSD1 also outgrew wild-type plants. AOHSD phenotypes were similar to those of plants that overproduced brassinosteroids (BRs) or overexpressed the BR receptor gene BRI1. A loss-of-function hsd mutant produced by RNA interference displayed a semidwarfed phenotype with reduced sensitivity to BRs. In contrast, AOHSD plants were hypersensitive to BRs and exhibited increased catabolism of abscisic acid (ABA). Germination of AOHSD seeds was less sensitive to ABA, while hsd seed was more sensitive to ABA during germination. AtHSD transcription was rapidly induced by BR treatment in wild type and was expressed widely in aerial plant parts, especially vascular tissues. This study demonstrates that AtHSD1 is involved in regulating growth and development in plants and is likely to promote or mediate BR effects. The gene has significant potential for improving growth and yield of canola and other agricultural crops.
1 This work was supported by the Genome and Health initiative of the National Research Council of Canada and by Genome Canada and Genome Prairie under the program "Enhancing canola through genomics." This article is National Research Council of Canada number 48416.
2 Present address: Department of Botany, 6270 University Blvd., University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Adrian J. Cutler (adrian.cutler{at}nrc-cnrc.gc.ca).
www.plantphysiol.org/cgi/doi/10.1104/pp.107.100560
* Corresponding author; e-mail adrian.cutler{at}nrc-cnrc.gc.ca.
Received April 3, 2007;
accepted June 22, 2007;
published July 6, 2007.
This article has been cited by other articles:

|
 |

|
 |
 
S. Baud, N. R. Dichow, Z. Kelemen, S. d'Andrea, A. To, N. Berger, M. Canonge, J. Kronenberger, D. Viterbo, B. Dubreucq, et al.
Regulation of HSD1 in Seeds of Arabidopsis thaliana
Plant Cell Physiol.,
August 1, 2009;
50(8):
1463 - 1478.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Alonso, L. Onate-Sanchez, F. Weltmeier, A. Ehlert, I. Diaz, K. Dietrich, J. Vicente-Carbajosa, and W. Droge-Laser
A Pivotal Role of the Basic Leucine Zipper Transcription Factor bZIP53 in the Regulation of Arabidopsis Seed Maturation Gene Expression Based on Heterodimerization and Protein Complex Formation
PLANT CELL,
June 1, 2009;
21(6):
1747 - 1761.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|