Publication
Title
Gibberellin signaling controls cell proliferation rate in **Arabidopsis**
Author
Abstract
Plant growth involves the integration of many environmental and endogenous signals that together with the intrinsic genetic program determine plant size. At the cellular level, growth rate is regulated by the combined activity of two processes: cell proliferation and expansion. Gibberellins (GA) are plant-specific hormones that play a central role in the regulation of growth and development with respect to environmental variability [1], [2] and [3]. It is well established that GA promote growth through cell expansion by stimulating the destruction of growth-repressing DELLA proteins (DELLAs) [1], [4], [5] and [6]; however, their effects on cell proliferation remain unknown. Kinematic analysis of leaf and root meristem growth revealed a novel function of DELLAs in restraining cell production. Moreover, by visualizing the cell cycle marker cyclinB1::â-glucuronidase in GA-signaling mutants, we show that GA modulate cell cycle activity in the root meristem via a DELLA-dependent mechanism. Accordingly, expressing gai (a nondegradable DELLA protein [4]) solely in root meristem reduced substantially the number of dividing cells. We also show that DELLAs restrain cell production by enhancing the levels of the cell cycle inhibitors Kip-related protein 2 (KRP2) and SIAMESE (SIM). Therefore, DELLAs exert a general plant growth inhibitory activity by reducing both cell proliferation and expansion rates, enabling phenotypic plasticity.
Language
English
Source (journal)
Current biology. - London
Publication
London : 2009
ISSN
0960-9822
Volume/pages
19:14(2009), p. 1188-1193
ISI
000268530200025
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 21.01.2010
Last edited 02.11.2017
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