World’s first blue chrysanthemums through gene engineering

Chrysanthemums (Chrysanthemum morifolium) are the second best-selling flowers after roses in the world. In Japan, they are by far the most popular and the 16 petal chrysanthemum with sixteen tips represents the Imperial Crest. Cultivated chrysanthemums have been generated by hybridization breeding of many wild species for hundreds or possibly thousands of years. Their flowers are pink, red, magenta, yellow, or white, but never violet-blue because chrysanthemums lack the key gene (the so-called blue gene, flavonoid 3′,5′-hydroxylase (F3′5′H) gene) to synthesize the delphinidin-based pigments which most violet-blue flowers accumulate.
Bluish-colored cultivars are not available in major cut flowers such as rose, carnation, chrysanthemum, lily, and gerbera due to the deficiency of F3′5′H gene. Genetic engineering techniques have enabled expression of the F3′5′H gene in rose (Rosa hybrida) and carnation (Dianthus caryophyllus) leading to novel varieties with violet-blue hued flowers accumulating delphinidin-based anthocyanins. The color-modified carnations are sold in USA, EU, Japan, and other countries; the rose is sold only in Japan. Until now comparable genetically modified chrysanthemum varieties had not been developed due to recalcitrant and unpredictable expression of introduced genes; the chrysanthemum tends to shut them off by as yet unknown mechanisms.

Also under development: fragrant moss, glow-in-the-dark plants, hyper-fragrant blossoms and flowers that don’t wilt. A Colorado company is working to engineer petunias that change colors throughout the day — from pink to blue and back to pink again, over 12 hours.
There were two technical barriers that had to be solved to produce blue flowers, according to researchers. One was to isolate the genes necessary to synthesize a blue pigment from among tens of thousands of genes contained in other types of blue flowers. The other was to develop the methods to introduce these genes to cells of chrysanthemums, roses and carnations — and then produce genetically-modified blossoms from these cells.