First published online May 9, 2008
Development 135, 1102e (2008)
© The Company of Biologists Limited
Complexities of trichome patterning
In plants, the regular pattern of trichomes (leaf hairs) is thought to be
generated during development through intercellular communication. That is,
trichome inhibitors, which are activated by self-enhanced trichome activators,
move between cells to determine the trichome pattern. On
p. 1991, Zhao and
colleagues refine this model, which is largely based on data obtained from the
root hair system, through a detailed analysis of the TTG1-bHLH-MYB complex,
which activates trichome initiation and patterning in Arabidopsis. By
co-precipitation, they confirm that the WD40 repeat protein TTG1 associates
with the bHLH protein GL3 and the R2R3-MYB protein GL1 in vivo. They identify
the trichome activators GL2 and TTG2, and repressors
CPC and ETC1 as being transcriptional targets of this
complex by showing that GL1 and TTG1 bind to their promoters in vivo. Finally,
they provide the first direct evidence that the trichome repressor CPC moves
between cells in developing leaves. Thus, they conclude, the TTG1-bHLH-MYB
complex affects trichome patterning by directly regulating downstream targets
and the movement of trichome repressors.
Related articles in Development:
- The TTG1-bHLH-MYB complex controls trichome cell fate and patterning through direct targeting of regulatory loci
- Mingzhe Zhao, Kengo Morohashi, Greg Hatlestad, Erich Grotewold, and Alan Lloyd
Development 2008 135: 1991-1999.
[Abstract]
[Full Text]
