The role of auxin in the pattern formation of the Asteraceae flower head (capitulum)

Nicholas Zoulias, S. Duttke, Helena Garces, Victoria Spencer, Minsung Kim

Research output: Contribution to journalArticlepeer-review

19 Downloads (Pure)


Nature often creates complex structures by rearranging pre-existing units. One such example is the flower head (capitulum) in daisies, where a group of flowers (florets) and phyllaries (modified bracts) are arranged to superficially mimic a single flower. The capitulum is a key taxonomical innovation that defines the daisy family (Asteraceae), the largest flowering plant group. However, patterning mechanisms underlying its structure remain elusive. Here, we show that auxin, a plant hormone, provides a developmental patterning cue for the capitulum. During capitulum development, a temporal auxin gradient occurs, regulating the successive and centripetal formation of distinct florets and phyllaries. Disruption of the endogenous auxin gradient led to homeotic conversions of florets and phyllaries in the capitulum. Furthermore, auxin regulates floral meristem identity genes, such as Matricaria inodora RAY2 and Matricaria inodora LFY, which determine floret and phyllary identity. This study reveals the mechanism of capitulum patterning and highlights how common developmental tools, such as hormone gradients, have independently evolved in plants and animals.
Original languageEnglish
JournalPlant Physiology
Publication statusPublished - Feb 2019


Dive into the research topics of 'The role of auxin in the pattern formation of the Asteraceae flower head (capitulum)'. Together they form a unique fingerprint.

Cite this