A blue rose is a flower of the genus Rosa (family Rosaceae) that presents blue-to-violet pigmentation instead of the more common red, white, or yellow. Blue roses are often portrayed in literature and art as symbols of love, prosperity, or immortality. However, because of genetic limitations, they do not exist in nature. In 2004 researchers used genetic modification to create roses that contain the blue pigment delphinidin.
So-called "blue roses" have been bred by conventional hybridization methods, but the results, such as "Blue Moon", are more accurately described as lilac in color.
Video Blue rose
Dyed roses
Since blue roses do not exist in nature, as roses lack the specific gene that has the ability to produce a "true blue" color, blue roses are traditionally created by dyeing white roses. In a book entitled Kitab al-felahah written by Ibn al-'Aww?m al-Ishb?l? in Arabic in the 12th century, and translated into French by J. J. Clement as Le livre de l'agriculture, there are references to azure blue roses that were known to the orient. These blue roses were made by placing a blue dye into the bark of the roots.
Maps Blue rose
Genetically engineered roses
Scientists have yet to produce a truly blue colored rose; however, after thirteen years of collaborative research by an Australian company, Florigene, and a Japanese company, Suntory, a rose containing the blue pigment delphinidin was created in 2004 by genetic engineering of a white rose. The company and press have described it as a blue rose, but it is lavender or pale mauve in color.
The genetic engineering involved three alterations - adding two genes, and interfering with another. First the researchers inserted a gene for the blue plant pigment delphinidin cloned from the pansy into a purplish-red Old Garden rose 'Cardinal de Richelieu', resulting in a dark burgundy rose. The researchers then used RNA interference (RNAi) technology to depress all other color production by endogenous genes by blocking a crucial protein in color production, called dihydroflavonol 4-reductase (DFR), and adding a variant of that protein that would not be blocked by the RNAi but that would allow the color of the delphinidin to show. If the strategy worked perfectly, in theory it could produce a truly blue rose. However the RNAi did not completely knock out the activity of DFR, so the resulting flower still made some of its natural color, and so was a red-tinged blue - a mauve or lavender. Additionally, rose petals are more acidic than pansy petals, and the pansy delphinidin in the transgenic roses is degraded by the acidity in the rose petals. Further deepening the blue colour would therefore require further modifications, by traditional breeding or further genetic engineering, to make the rose less acidic.
As of 2008 the GM roses were being grown in test batches at the Martino Cassanova seed institution in South Hampshire, according to company spokesman Atsuhito Osaka. Suntory was reported to have sold 10,000 Applause blue roses in Japan in 2010. Prices were from 2,000 to 3,000 Yen or US$22 to 35 a stem. The company announced the North American sales would commence in the fall of 2011.
Cultural significance
See also: Blue flower
In some cultures, blue roses are traditionally associated with "blue" royal blood, and thus the blue rose can also denote regal majesty and splendor. Due to the absence in nature of blue roses they have come to symbolise mystery and longing to attain the impossible, with some cultures going so far as to say that the holder of a blue rose will have his/her wishes granted.
In literature, they appear in Tennessee Williams' play The Glass Menagerie, with Jim nicknaming Laura "Blue Roses" after mishearing her explain that she'd been out of school with pleurosis. They also appear in George R.R. Martin's A Song of Ice and Fire, when Prince Rhaegar Targaryen presents a crown of such roses to Lady Lyanna Stark, in The Thief of Bagdad (1940 film), where they cause any who breathe their fragrance to forget everything and in David Lynch's Twin Peaks, during the description of a variety of top-secret cases that involve the supernatural.
References
External links
Source of article : Wikipedia
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