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From priming to plasticity: the changing fate of rhizodermic cells
Author(s) -
Savage Natasha Saint,
Schmidt Wolfgang
Publication year - 2008
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.20693
Subject(s) - root hair , microbiology and biotechnology , biology , downregulation and upregulation , priming (agriculture) , cell fate determination , biophysics , botany , biochemistry , gene , transcription factor , germination
The fate of root epidermal cells is controlled by a complex interplay of transcriptional regulators, generating a genetically determined, position‐biased arrangement of root hair cells. This pattern is altered during postembryonic development and in response to environmental signals to confer developmental plasticity that acclimates the plant to the prevailing conditions. Based on the hypothesis that events downstream of this initial mechanism can modulate the pattern installed during embryogenesis, we have developed a reaction diffusion model that reproduces the root hair patterning previously observed experimentally. Under all growth conditions, an almost equal spacing between root hair forming cells was observed both in vitro and in silico, indicating that long‐range intercellular communication is crucial for the trichoblasts' decision to form a root hair. We assume that a hair growth promoter (HGP) is upregulated in root‐hair‐forming cells by a trichoblast‐specific component. Once established, HGP production is self‐enhancing. The autocatalytic regulation of HGP is antagonized by an HGP‐produced hair growth inhibitor (HGI). HGI is exported from trichoblasts and diffuses to neighboring cells, where it inhibits further HGP production and promotes the non‐hair cell fate. Under conditions of phosphate deficiency, we hypothesise that HGP production is increased and HGI diffusion rate is reduced, leading to a position‐independent formation of extra root hairs. BioEssays 30:75–81, 2008. © 2007 Wiley Periodicals, Inc.