World’s first blue rose

CSIRO PLANT INDUSTRY

Breeding a blue rose has been the ‘Holy Grail’ of rose breeding for centuries, but roses have proven a particularly difficult candidate to turn blue. That has all now changed with the joint venture between the Australian based Florigene and the Japanese Suntory company, successfully using CSIRO’s gene silencing technology to help create the world’s first blue rose.

Roses are famous for their

beautiful colours including red, pink, orange, yellow and even

white. These colours have been developed through traditional

breeding but never has a blue rose successfully been bred.

Some mauve roses have been

bred but as it turns out these

colours are actually produced by variations of red pigment

not by the production of blue pigment.

To develop the world’s first blue rose with blue pigment three steps had to be achieved: 1. Turn off the production of red pigment; 2. Open the ‘door’ to production of blue pigment; and then 3. Produce blue pigment. One gene involved in flower colour, is the dihydroflavonol reductase (DFR) gene. The DFR gene makes the enzyme dihydroflavonol reductase (DFR) which turns on the manufacturing process in the plant that produces pigment that in turn colours flowers. In roses the DFR gene is very good at producing red pigment and hence the range of commonly seen rose colours. However, the rose DFR gene is particularly bad at producing blue pigment, hence the difficulty in breeding a blue rose. The first critical step in producing a blue rose was to stop the rose DFR gene making red pigment. Preventing red pigment CSIRO first developed gene silencing, or hairpin RNAi, in 1997. It was a significant breakthrough allowing scientists to turn down or switch off completely the activity of genes. Gene silencing uses a natural mechanism that degrades RNA – the courier that delivers the gene’s instructions to make proteins, like the enzyme DFR. Florigene and Suntory used CSIRO’s gene silencing technology to turn off the activity of the rose DFR gene so that it didn’t produce red pigment. Gene silencing has been used in a number of research applications to determine gene function and in the development of experimental plants with favourable properties. Its use in the development of the blue rose is likely to be its first commercial application.

World’s first blue rose The blue rose – developed using CSIRO’s hairpin RNAi Photo courtesy of Florigne Ltd / Suntory Ltd