Genetic control of flower development, color and senescence of Dendrobium orchids

• This review focuses on the floral transition from the vegetative to the reproductive phase in Dendrobium orchids.
• The review also focuses on the genetics of flower development, color and senescence.
• The economic importance of Dendrobium and the rich literature make it a suitable model orchid.
• Introduction of Dendrobium homologs into Arabidopsis thaliana sheds light on the ABCDE model and the “orchid code”.

For ornamental plants, in particular orchids, the flower is central to their beauty and commercial value. The ability to manipulate the floral transition from the vegetative to the reproductive phase and floral traits requires an understanding of the underlying molecular genetic mechanisms and robust transgenic protocols. Using Dendrobium species and hybrids, this review explores the advances that have been made in the genetics of flower development, color and senescence. Although the homologs of several MADS-box genes are still to be found, those that have already been cloned and analyzed bring promise to what has yet to be unraveled about the control of flower color and development. Recent advances in orchid transformation and the introduction of Dendrobium homologs into Arabidopsis thaliana have shed new light on the complexities of flower color and the ABCDE model of flower development in orchids, or the ‘orchid code’.