Abstract: Genetically-modified, colour-altered varieties of the important cut-flower crop
carnation have now been commercially available for nearly ten years. In this review we
describe the manipulation of the anthocyanin biosynthesis pathway that has lead to the
development of these varieties and how similar manipulations have been successfully
applied to both pot plants and another cut-flower species, the rose. From this experience it
is clear that down- and up-regulation of the flavonoid and anthocyanin pathway is both
possible and predictable. The major commercial benefit of the application of this
technology has so far been the development of novel flower colours through the
development of transgenic varieties that produce, uniquely for the target species,
anthocyanins derived from delphinidin. These anthocyanins are ubiquitous in nature, and
occur in both ornamental plants and common food plants. Through the extensive regulatory
approval processes that must occur for the commercialization of genetically modified
organisms, we have accumulated considerable experimental and trial data to show the
accumulation of delphinidin based anthocyanins in the transgenic plants poses no
environmental or health risk.
Keywords: anthocyanin; flavonoid; flower colour; genetic engineering; genetically
modified organism (GMO)