Academy of Finland, 310318
One of the key questions in biology is how organisms generate reproducible patterns in a highly precise manner. In plants, inflorescences are the branched structures that bear flowers. Their architecture, in terms of number and arrangement (phyllotaxis) of flowers, show enormous variation in nature and plays a central role in reproductive success and adaptation of plants as well as yield in crops. The unique feature in the Asteraceae (sunflower) plant family is that their inflorescence forms a pseudanthium, or false flower. While it superficially mimics a solitary flower, it is actually a tightly packed flower head (capitulum) composed of morphologically and structurally distinct types of flowers. This transference of a flower-like identity into an inflorescence is considered as the key innovation for the diversification of this largest family of flowering plants. Individual flowers in the capitulum are packed in left and right winding spirals whose number follow a famous mathematical rule found in nature; the Fibonacci numbers. This intriguing geometric regularity has fascinated both botanists and mathematicians for centuries. Our major aim is to tackle the dynamic networks of cellular and molecular interactions during early capitulum patterning. We will specifically focus on early patterning, establishment of spiral phyllotaxis, and on signaling that regulates determinacy of the capitulum and leads to floral dimorphism, i.e. differentiation of distinct flower types or higher order aggregation. The knowledge obtained in this project will be used refine the mathematical models to understand capitulum organization.
Effective start/end date01/09/201731/08/2021