First published online April 13, 2007
Development 134, 902e (2007)
© The Company of Biologists Limited
The shape of attraction
Petal colour intensity is an adaptation that flowering plants have made to
lure pollinating insects. A conical-shaped petal epidermal cell has increased
colour intensity because more incidental light is reflected into it. MIXTA, a
MYB-related transcription factor, regulates conical cell shape development in
snapdragon (Antirrhinum majus) petals. Cathie Martin and co-workers
report that proteins closely related to MIXTA from both A. majus and
other angiosperms have similar, but distinct, roles in petal epidermal cell
shape formation (p.
1691). Cell shape contributes to the overall petal curvature, and
thus flower shape, a role not previously associated with MIXTA-like proteins.
Using genetic mutants from snapdragon and petunia (Petunia hybrida),
the authors reveal the occurrence of flatter epidermal cells in mixta
mutants and of shallow, conically shaped cells in petunia phmyb1
mutants. They propose that an altered direction of growth, followed by growth
extension, generates cell shape in this setting. This family of transcription
factors, in modifying the petal epidermal cell shape, fulfil a crucial role in
attracting insects, thus ensuring pollination.
Related articles in Development:
- Control of cell and petal morphogenesis by R2R3 MYB transcription factors
- Kim Baumann, Maria Perez-Rodriguez, Desmond Bradley, Julien Venail, Paul Bailey, Hailing Jin, Ronald Koes, Keith Roberts, and Cathie Martin
Development 2007 134: 1691-1701.
[Abstract]
[Full Text]
