Scientists have discovered an unusual and novel role for the plant hormone
auxin in the development of the female organs of the flower. Plant
scientists Professor Lars ?stergaard and Laila Moubayidin from the John
Innes Centre in Norwich have discovered that tissue at the tip of the
gynoecium, the structure that forms the female reproductive organ of a
flower, goes through a bilateral to radial transition. The resulting radial
structure makes up the style of the gynoecium.
Using Arabidopsis thaliana in their experiments, the researchers found this
unusual transition to be controlled by two genes directly affecting auxin
distribution. A radial style is crucial for effective fertilization since
the tubular shape supports the growth of pollen tubes into the gynoecium.
These carry sperm from the flower's male parts towards the female gametes,
ultimately leading to the development of a new plant embryo.