The science of spring flowers—how petals get their shape

April 30, 2013

Why do rose petals have rounded ends while their leaves are more pointed? In a new study published April 30 in the open access journal PLOS Biology, scientists from the John Innes Centre and University of East Anglia, UK, reveal that the shape of petals is controlled by a hidden map located within the plant's growing buds.

Leaves and petals perform different functions related to their shape. Leaves acquire sugars for a plant via photosynthesis, which can then be transported throughout the plant. Petals develop later in the life cycle and help attract pollinators. In earlier work, this team had discovered that leaves in the plant Arabidopsis contain a hidden map that orients growth in a pattern that converges towards the tip of the bud, giving leaves their characteristic pointed tips. In the new study, the researchers discover that Arabidopsis petals contain a similar, hidden map that orients growth in the flower's bud. However, the pattern of growth is different to that in leaves - in the petal growth is oriented towards the edge giving a more rounded shape - accounting for the different shapes of leaves and petals. The researchers discovered that molecules called PIN proteins are involved in this oriented growth, which are located towards the ends of each cell.

"The discovery of these hidden polarity maps was a real surprise and provides a simple explanation for how different shapes can be generated," said Professor Enrico Coen, senior author of the study.

The team of researchers confirmed their ideas by using computer simulations to test which maps could predict the correct petal shape. They then confirmed experimentally that PIN proteins located to the right sites to be involved in oriented growth, and identified that another protein, called JAGGED, is involved in promoting growth towards the edge of petals and in establishing the hidden map that determines petal growth and shape.

Unlike animal cells, plant cells are unable to move and migrate to form structures of a particular shape, and so these findings help to explain how plants create differently shaped organs - by controlling rates and orientations of cell growth. From an evolutionary perspective, this system creates the flexibility needed for plant organs to adapt to their environment and to develop different functions.

Explore further: How size matters: The beauty of nature explained

More information: Sauret-Güeto S, Schiessl K, Bangham A, Sablowski R, Coen E (2013) JAGGED Controls Arabidopsis Petal Growth and Shape by Interacting with a Divergent Polarity Field. PLoS Biol 11(4): e1001550. doi:10.1371/journal.pbio.1001550

Related Stories

How size matters: The beauty of nature explained

December 12, 2007

The beauty of nature is partly due to the uniformity of leaf and flower size in individual plants, and scientists have discovered how plants arrive at these aesthetic proportions.

Proper flower and leaf development tied to the same gene

January 12, 2010

( -- A group of Dartmouth researchers have discovered a new role for an important plant gene. Dartmouth Biology Professor Tom Jack and his colleagues have learned that a gene regulator called miR319a (micro RNA ...

How the dragon got its 'snap'

November 9, 2010

Scientists at the John Innes Centre and the University of East Anglia are pioneering a powerful combination of computer modeling and experimental genetics to work out how the complex shapes of organs found in nature are produced ...

Scientists present first model of how buds grow into leaves

March 1, 2012

Leaves come in all shapes and sizes. Scientists have discovered simple rules that control leaf shape during growth. Using this 'recipe', they have developed the first computer model able to accurately emulate leaf growth ...

Recommended for you

A common mechanism for human and bird sound production

November 27, 2015

When birds and humans sing it sounds completely different, but now new research reported in the journal Nature Communications shows that the very same physical mechanisms are at play when a bird sings and a human speaks.

Study suggests fish can experience 'emotional fever'

November 25, 2015

(—A small team of researchers from the U.K. and Spain has found via lab study that at least one type of fish is capable of experiencing 'emotional fever,' which suggests it may qualify as a sentient being. In their ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.