Working toward the emergence of visibly blue roses

Even after blue pigments are produced, how blue the flower become depends greatly on the original characteristics of the roses to which genes are introduced. For example, if the pH is low (acidic) in the cell vacuoles in which blue pigments are accumulated, the color becomes red, and if it is neutral, the color becomes blue. The color also depends largely on whether components that can or cannot enhance blue exist in the vacuoles. In other words, the existence of blue pigments does not necessarily turn the flower color into blue.

We therefore chose, from among several hundred varieties, about 40 rose varieties which would be likely to result in the accumulation of a high percentage of blue pigments and a more bluish color, including those that were not commercialized, and continued experiments to introduce the blue genes in order to produce roses that really would look blue. At the same time, we continued our research to improve methods of tissue culture so that genes could be introduced into various rose varieties.

We were excited about the prospect of blue roses coming! (Senior General Manager Yoshikazu Tanaka Ph.D.)

Mate of the destiny; pansies

Genes of various plants, such as gentian and lavender were tried, but what produced blue pigments in roses were pansies. This was found with no necessity. We selected representative blue flower species from each category of plant classification named “family,” and tried various flowers, and succeeded in the experiments of pansies quite by chance. There was no presumption that pansies would work.

Experiments were conducted jointly in Japan and Australia, and blue pigments were first produced in Australia, so I felt a little disappointed. Since the time when I returned to Japan in 1994, experimental systems in Japan improved, and experiments were conducted in parallel with experiments in Australia. Subsequently, experiments introducing genes of pansies were also conducted in Japan.

Blue pigment led to breakthrough although no blue color

When blue pigments were expressed in roses for the first time, their content was about 50% of total pigments. Still, we were all excited to receive the news. The change from zero to one (from absence to presence) was a big breakthrough.

The color of the roses was not blue but murky dark red at best. But we had a bright prospect because we believed that the color would turn blue someday with continuous efforts to improve it.

Even if the amount is small, there is a big difference between zero and one when we think about future possibilities. We were convinced that “this was a good result, indicating that our research was advancing in the right direction.” This was a big turning point in the blue rose project.

Our research was worthwhile though we had to cope with pressure (Principal Researcher Yukihisa Katsumoto, Ph.D.)

White roses with blue genes did not turn blue!?

Introduction of blue genes is relatively easy for some rose varieties whereas it is not for the other varieties. First, we introduced the genes into red roses. It was difficult to turn them blue, so we started to choose varieties for which introduction of the genes was relatively easy and which would easily turn blue.

It has been often pointed out that white roses may easily turn blue, but many white roses do not have the ability to produce pigments, and they do not necessarily turn blue even if blue genes are introduced.

We do not know yet why it was more difficult to produce blue pigments in roses than in carnations. As plants have mechanisms to degrade unnecessary nucleotide sequences, for example, the petunia blue gene might have happened to be the sequences that the roses wanted to degrade. However, this is only my imagination. There is no big difference between roses and carnations as to how easy it is to introduce genes.

All the members believed in the success of the project

Some people have said to me, “You must have been patient not to give up the project when no fruitful result was obtained.” If the members who are directly involved in this kind of project do not believe in the success, it will never be successful.

To think positively and consider that “there is no reason not to be successful” is just about the right attitude. If there had been even one team member who had given up, APPLAUSE would not have been born.

I felt pressure due to the expectations and dreams that many people had, but I even enjoyed the sense of pressure. If nobody had cared, there would have been no pressure, but the work itself would not have been worthwhile. I have worked, considering that I have been expected to do so.

• Research papers on flower
• Conference presentations on flower