First published online June 25, 2007
Development 134, 1401e (2007)
© The Company of Biologists Limited
Antagonism in Arabidopsis mediates patterning
Auxin regulates gene expression in Arabidopsis through Auxin
Response Factors (ARFs). While most ARF functions remain elusive, patterning
functions have been assigned to some, including MONOPTEROS
(MP/ARF5), which promotes stem cell formation in the root and shoot
apical meristem. Thomas Berleth's group now show that MP primarily
functions to counteract the activity of the carboxypeptidase ALTERED
MERISTEM PROGRAM 1 (AMP1), which restricts meristem size. Their
analysis of single and double mutants in Arabidopsis, reported on
p. 2561, reveals that
in the absence of AMP1 activity, MP patterning activity is
largely dispensible, and that in MP mutants, meristem cells
differentiate because of unimpeded AMP1 activity. These researchers
propose that MP represses AMP1's activity and maintains
niches, an idea that is supported by the two genes' overlapping expression
domains: where they overlap, antagonism occurs. As AMP1 transcript
levels are normal in MP mutants, this antagonism is not
transcriptionally regulated. Moreover, MP and AMP1 localise to different
cellular compartments, so exactly how this antagonism occurs remains
unknown.
Related articles in Development:
- AMP1 and MP antagonistically regulate embryo and meristem development in Arabidopsis
- Danielle P. Vidaurre, Sara Ploense, Naden T. Krogan, and Thomas Berleth
Development 2007 134: 2561-2567.
[Abstract]
[Full Text]