The fully linked HTML version of this article has now been published.
Development ePress online publication date 8 Apr 2004
doi: 10.1242/dev.01096
Research article
The HALTED ROOT gene encoding the 26S proteasome subunit RPT2a is essential for the maintenance of Arabidopsis meristems
Minako Ueda,
Keisuke Matsui,
Sumie Ishiguro,
Ryosuke Sano,
Takuji Wada,
Ivan Paponov,
Klaus Palme,
and
Kiyotaka Okada*
* Author for correspondence (e-mail: kiyo{at}ok-lab.bot.kyoto-u.ac.jp)
In higher plants, post-embryonic development is dependent on the activity of the root and shoot apical meristem (RAM and SAM). The quiescent center (QC) in the RAM and the organizing center (OC) in the SAM are known to be essential for the maintenance of meristematic activity. To understand the mechanism that maintains post-embryonic meristems, we isolated an Arabidopsis mutant, halted root (hlr). In this mutant, the cellular organization was disrupted in post-embryonic meristems both in the root and in the shoot, and their meristematic activity was reduced or became abnormal. We showed that the mutant RAM lost its QC identity after germination, which was specified during embryogenesis, whereas the identity of differentiated tissues was maintained. In the post-embryonic SAM, the expression pattern of a typical OC marker gene, WUSCHEL, was disturbed in the mutant. These observations indicate that the HLR gene is essential to maintain the cellular organization and normal nature of the RAM and SAM. The HLR gene encodes RPT2a, which is a subunit of the 26S proteasome that degrades key proteins in diverse cellular processes. We showed that the HLR gene was expressed both in the RAM and in the SAM, including in the QC and the OC, respectively, and that the activity of proteasomes were reduced in the mutant. We propose that proteasome-dependent programmed proteolysis is required to maintain the meristem integrity both in the shoot and in the root.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:

|
 |

|
 |
 
J. Kurepa, S. Wang, Y. Li, D. Zaitlin, A. J. Pierce, and J. A. Smalle
Loss of 26S Proteasome Function Leads to Increased Cell Size and Decreased Cell Number in Arabidopsis Shoot Organs
Plant Physiology,
May 1, 2009;
150(1):
178 - 189.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
N. Yagi, S. Takeda, N. Matsumoto, and K. Okada
VAJ/GFA1/CLO is Involved in the Directional Control of Floral Organ Growth
Plant Cell Physiol.,
March 1, 2009;
50(3):
515 - 527.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J.-L. Gallois, A. Guyon-Debast, A. Lecureuil, D. Vezon, V. Carpentier, S. Bonhomme, and P. Guerche
The Arabidopsis Proteasome RPT5 Subunits Are Essential for Gametophyte Development and Show Accession-Dependent Redundancy
PLANT CELL,
February 1, 2009;
21(2):
442 - 459.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. J. Book, J. Smalle, K.-H. Lee, P. Yang, J. M. Walker, S. Casper, J. H. Holmes, L. A. Russo, Z. W. Buzzinotti, P. D. Jenik, et al.
The RPN5 Subunit of the 26s Proteasome Is Essential for Gametogenesis, Sporophyte Development, and Complex Assembly in Arabidopsis
PLANT CELL,
February 1, 2009;
21(2):
460 - 478.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Han, H. Cao, J. Jiang, Y. Xu, J. Du, X. Wang, M. Yuan, Z. Wang, Z. Xu, and K. Chong
Rice ROOT ARCHITECTURE ASSOCIATED1 Binds the Proteasome Subunit RPT4 and Is Degraded in a D-Box and Proteasome-Dependent Manner
Plant Physiology,
October 1, 2008;
148(2):
843 - 855.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. Chae, Q. K.-G. Tan, T. A. Hill, and V. F. Irish
An Arabidopsis F-box protein acts as a transcriptional co-factor to regulate floral development
Development,
April 1, 2008;
135(7):
1235 - 1245.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Shishkova, T. L. Rost, and J. G. Dubrovsky
Determinate Root Growth and Meristem Maintenance in Angiosperms
Ann. Bot.,
February 1, 2008;
101(3):
319 - 340.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Bouchard, A. Bailly, J. J. Blakeslee, S. C. Oehring, V. Vincenzetti, O. R. Lee, I. Paponov, K. Palme, S. Mancuso, A. S. Murphy, et al.
Immunophilin-like TWISTED DWARF1 Modulates Auxin Efflux Activities of Arabidopsis P-glycoproteins
J. Biol. Chem.,
October 13, 2006;
281(41):
30603 - 30612.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. Huang, L. Pi, W. Liang, B. Xu, H. Wang, R. Cai, and H. Huang
The Proteolytic Function of the Arabidopsis 26S Proteasome Is Required for Specifying Leaf Adaxial Identity
PLANT CELL,
October 1, 2006;
18(10):
2479 - 2492.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. Jin, S. Li, and A. Villegas Jr.
Down-Regulation of the 26S Proteasome Subunit RPN9 Inhibits Viral Systemic Transport and Alters Plant Vascular Development
Plant Physiology,
October 1, 2006;
142(2):
651 - 661.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. Brukhin, J. Gheyselinck, V. Gagliardini, P. Genschik, and U. Grossniklaus
The RPN1 Subunit of the 26S Proteasome in Arabidopsis Is Essential for Embryogenesis
PLANT CELL,
October 1, 2005;
17(10):
2723 - 2737.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
I. Baurle and T. Laux
Regulation of WUSCHEL Transcription in the Stem Cell Niche of the Arabidopsis Shoot Meristem
PLANT CELL,
August 1, 2005;
17(8):
2271 - 2280.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. C. Carles, D. Choffnes-Inada, K. Reville, K. Lertpiriyapong, and J. C. Fletcher
ULTRAPETALA1 encodes a SAND domain putative transcriptional regulator that controls shoot and floral meristem activity in Arabidopsis
Development,
March 1, 2005;
132(5):
897 - 911.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2004