Evolution and developmental genetics of floral display—A review of progress

Abstract

Angiosperms evolved a great diversity of ways to display their flowers for reproductive success by variation in floral color, size, shape, scent, arrangements, and flowering time. The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences can drive new ecological adaptations, speciation, and angiosperm diversification. Evolutionary developmental biology (evo-devo) seeks to uncover the developmental and genetic basis underlying morphological diversification. Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution. A number of regulatory genes controlling floral and inflorescence development have been identified in model plants (e.g., Arabidopsis thaliana, Antirrhinum majus) using forward genetics and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics. Gene-regulatory networks that mediated the developmental progresses of floral and inflorescence development have also been established in some plant species. Meanwhile, phylogeny-based comparative analysis of morphological and genetic character has enabled the identification of key evolutionary events that lead to morphological complexity and diversification. Here we review the recent progress on evo-devo studies of floral display including floral symmetry, petal fusion, floral color, floral scent, and inflorescences. We also review the molecular genetic approaches applied to plant evo-devo studies and highlight the future directions of evo-devo.