The MADS-box Genes Involved in Orchid Flower Development
Pp. 113-142 (30)
Serena Aceto and Luciano Gaudio
Since the advent of Darwinian genetics, there has been much interest in the
evolutionary origin of the Orchidaceae, one of the most species-rich angiosperm
families. Orchids have highly diversified and specialized flowers, and some species
exhibit an uncoupled rate of morphological and molecular evolution. Recently, these
peculiar characteristics have enhanced the study of the orchid MADS-box genes
involved in flower development. This large gene family encodes transcription factors
that constitute the main regulatory network driving the formation of flower organs.
Recent analyses have highlighted the role of the MADS-box genes in orchids and
shown that different evolutionary forces act on the coding and non-coding regions of
these genes. The most widely accepted theory proposed to explain the evolution of the
orchid perianth is the “orchid code”, which posits that the orchid floral organs became
diversified through a series of duplications and mutations of the MADS-box genes,
followed by functional diversification.
ABCDE model, adaptation, column, consensus sequence, development,
evolution, flower, inflorescence, labellum, MADS-box, Orchidaceae, orchid code,
ovary, phylogeny, quartet model, regulation, resupination, tepals, transcription,
Department of Biology, University of Naples Federico II, via Mezzocannone 8, 80134 Napoli, Italy.