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Article|01 Jul 2018|OPEN
Flower heads in Asteraceae—recruitment of conserved developmental regulators to control the flower-like inflorescence architecture
Paula Elomaa1, Yafei Zhao1 & Teng Zhang1
1Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, P.O.Box 27, 00014 Helsinki, Finland

Horticulture Research 5,
Article number: 36 (2018)
doi: 10.1038/hortres.2018.36
Views: 506

Received: 03 Apr 2018
Revised: 31 May 2018
Accepted: 31 May 2018
Published online: 01 Jul 2018

Abstract

Inflorescences in the Asteraceae plant family, flower heads, or capitula, mimic single flowers but are highly compressed structures composed of multiple flowers. This transference of a flower-like appearance into an inflorescence level is considered as the key innovation for the rapid tribal radiation of Asteraceae. Recent molecular data indicate that Asteraceae flower heads resemble single flowers not only morphologically but also at molecular level. We summarize this data giving examples of how rewiring of conserved floral regulators have led to evolution of morphological innovations in Asteraceae. Functional diversification of the highly conserved flower meristem identity regulator LEAFY has shown a major role in the evolution of the capitulum architecture. Furthermore, gene duplication and subsequent sub- and neofunctionalization of SEPALLATA- and CYCLOIDEA-like genes in Asteraceae have been shown to contribute to meristem determinacy, as well as flower type differentiation—key traits that specify this large family. Future challenge is to integrate genomic, as well as evolutionary developmental studies in a wider selection of Asteraceae species to understand the detailed gene regulatory networks behind the elaborate inflorescence architecture, and to promote our understanding of how changes in regulatory mechanisms shape development.