|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online 24 November 2004
doi: 10.1242/dev.01544
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

1 Institute of Plant Science, University of Berne, Altenbergrain 21, 3013 Bern,
Switzerland
2 Institute of Applied Physics, University of Berne, Sidlerstrasse 5, 3012 Bern,
Switzerland
Author for correspondence (e-mail:
cris.kuhlemeier{at}ips.unibe.ch)
Accepted 25 October 2004
Leaves are arranged according to regular patterns, a phenomenon referred to as phyllotaxis. Important determinants of phyllotaxis are the divergence angle between successive leaves, and the size of the leaves relative to the shoot axis. Young leaf primordia are thought to provide positional information to the meristem, thereby influencing the positioning of new primordia and hence the divergence angle. On the contrary, the meristem signals to the primordia to establish their dorsoventral polarity, which is a prerequisite for the formation of a leaf blade. These concepts originate from classical microsurgical studies carried out between the 1920s and the 1970s. Even though these techniques have been abandoned in favor of genetic analysis, the resulting insights remain a cornerstone of plant developmental biology.
Here, we employ new microsurgical techniques to reassess and extend the classical studies on phyllotaxis and leaf polarity. Previous experiments have indicated that the isolation of an incipient primordium by a tangential incision caused a change of divergence angle between the two subsequent primordia, indicating that pre-existing primordia influence further phyllotaxis. Here, we repeat these experiments and compare them with the results of laser ablation of incipient primordia. Furthermore, we explore to what extent the different pre-existing primordia influence the size and position of new organs, and hence phyllotaxis. We propose that the two youngest primordia (P1 and P2) are sufficient for the approximate positioning of the incipient primordium (I1), and therefore for the perpetuation of the generative spiral, whereas the direct contact neighbours of I1 (P2 and P3) control its delimitation and hence its exact size and position. Finally, we report L1-specific cell ablation experiments suggesting that the meristem L1 layer is essential for the dorsoventral patterning of leaf primordia.
Key words: Tomato, Meristem, Phyllotaxis, Laser ablation, Dorsoventral, Patterning, Meristem layer, L1 layer
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
A. Y. Husbands, D. H. Chitwood, Y. Plavskin, and M. C.P. Timmermans Signals and prepatterns: new insights into organ polarity in plants Genes & Dev., September 1, 2009; 23(17): 1986 - 1997. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Szczesny, A.-L. Routier-Kierzkowska, and D. Kwiatkowska Influence of clavata3-2 mutation on early flower development in Arabidopsis thaliana: quantitative analysis of changing geometry J. Exp. Bot., February 1, 2009; 60(2): 679 - 695. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Efroni, E. Blum, A. Goldshmidt, and Y. Eshed A Protracted and Dynamic Maturation Schedule Underlies Arabidopsis Leaf Development PLANT CELL, September 1, 2008; 20(9): 2293 - 2306. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Han, Q. Li, and Y.-X. Zhu Mutation of Arabidopsis BARD1 Causes Meristem Defects by Failing to Confine WUSCHEL Expression to the Organizing Center PLANT CELL, June 1, 2008; 20(6): 1482 - 1493. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Yao, Q. Ling, H. Wang, and H. Huang Ribosomal proteins promote leaf adaxial identity Development, April 1, 2008; 135(7): 1325 - 1334. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y.-S. Kim, S.-G. Kim, M. Lee, I. Lee, H.-Y. Park, P. J. Seo, J.-H. Jung, E.-J. Kwon, S. W. Suh, K.-H. Paek, et al. HD-ZIP III Activity Is Modulated by Competitive Inhibitors via a Feedback Loop in Arabidopsis Shoot Apical Meristem Development PLANT CELL, April 1, 2008; 20(4): 920 - 933. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. T.S. Nogueira, S. Madi, D. H. Chitwood, M. T. Juarez, and M. C.P. Timmermans Two small regulatory RNAs establish opposing fates of a developmental axis Genes & Dev., April 1, 2007; 21(7): 750 - 755. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Chitwood, M. Guo, F. T. S. Nogueira, and M. C. P. Timmermans Establishing leaf polarity: the role of small RNAs and positional signals in the shoot apex Development, March 1, 2007; 134(5): 813 - 823. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. FAMBRINI, E. BONSIGNORI, F. RAPPARINI, G. CIONINI, V. MICHELOTTI, D. BERTINI, R. BARALDI, and C. PUGLIESI stem fasciated, a Recessive Mutation in Sunflower (Helianthus annuus), Alters Plant Morphology and Auxin Level Ann. Bot., October 1, 2006; 98(4): 715 - 730. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Balanza, M. Navarrete, M. Trigueros, and C. Ferrandiz Patterning the female side of Arabidopsis: the importance of hormones J. Exp. Bot., October 1, 2006; 57(13): 3457 - 3469. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Alvarez, I. Pekker, A. Goldshmidt, E. Blum, Z. Amsellem, and Y. Eshed Endogenous and Synthetic MicroRNAs Stimulate Simultaneous, Efficient, and Localized Regulation of Multiple Targets in Diverse Species PLANT CELL, May 1, 2006; 18(5): 1134 - 1151. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Jonsson, M. G. Heisler, B. E. Shapiro, E. M. Meyerowitz, and E. Mjolsness An auxin-driven polarized transport model for phyllotaxis PNAS, January 31, 2006; 103(5): 1633 - 1638. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Smith, S. Guyomarc'h, T. Mandel, D. Reinhardt, C. Kuhlemeier, and P. Prusinkiewicz A plausible model of phyllotaxis PNAS, January 31, 2006; 103(5): 1301 - 1306. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Pekker, J. P. Alvarez, and Y. Eshed Auxin Response Factors Mediate Arabidopsis Organ Asymmetry via Modulation of KANADI Activity PLANT CELL, November 1, 2005; 17(11): 2899 - 2910. [Abstract] [Full Text] [PDF] |
||||