Publication
Title
Gibberellin signaling in the endodermis controls **Arabidopsis** root meristem size
Author
Abstract
Plant growth is driven by cell proliferation and elongation [1]. The hormone gibberellin (GA) regulates Arabidopsis root growth [2], [3], [4] and [5] by controlling cell elongation [6], but it is currently unknown whether GA also controls root cell proliferation. Here we show that GA biosynthetic mutants are unable to increase their cell production rate and meristem size after germination. GA signals the degradation of the DELLA growth repressor proteins [7], [8], [9], [10], [11] and [12] GAI and RGA, promoting root cell production. Targeting the expression of gai (a non-GA-degradable mutant form of GAI) in the root meristem disrupts cell proliferation. Moreover, expressing gai in dividing endodermal cells was sufficient to block root meristem enlargement. We report a novel function for GA regulating cell proliferation where this signal acts by removing DELLA in a subset of, rather than all, meristem cells. We suggest that the GA-regulated rate of expansion of dividing endodermal cells dictates the equivalent rate in other root tissues. Cells must double in size prior to dividing but cannot do so independently, because they are physically restrained by adjacent tissues with which they share cell walls. Our study highlights the importance of probing regulatory mechanisms linking molecular- and cellular-scale processes with tissue and organ growth responses.
Language
English
Source (journal)
Current biology. - London
Publication
London : 2009
ISSN
0960-9822
Volume/pages
19:14(2009), p. 1194-1199
ISI
000268530200026
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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