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VOICE No. 32

Associate Professor

Katsuhiro Shiratake

Graduate School of Bioagricultural Sciences

My favorite phrase: Connecting the Dots


Q: Why did you choose this phrase?

I listened to speech that Steve Jobs gave about “connecting the dots,” and the concept of connecting the dots really resonated with me. It's the same as what's important to me in my own research and work. Each individual piece of knowledge or information or skill may be nothing more than a small fragment, but by connecting them together, we can build up big, revolutionary ideas. Likewise, by connecting with researchers who have different knowledge and experiences from mine, I can conduct major research that I couldn't have done on my own.


Q: What kind of research are you doing?

My research involves designing flowers, fruits, and vegetables by gene modification. I design crops — not only the color and shape but also the taste, smell, and nutritional composition. Our research focuses on horticultural crops like flowers, fruits, and vegetables. Although horticultural research doesn't prevent starvation, these studies are necessary to improve our quality of life — giving people access to the good nutrition they need to live, and enriching people's lives with the tastes, smells, and appearances of these plants. Using the latest techniques in biology, I try to identify the genes that are key to the quality of horticultural crops and alter those genes using genome editing and other genetic engineering in order to develop better breeds. This is how I want to help improve people's lives.





Upper: Petunias with brightly color petals. Gene modification had made it possible

to synthesize betalain pigment, which was originally unable to be synthesized.

   Lower: The gene, which induces greening of petals, was introduced in morning glory and petunia.



Q: How did you get into this research?

Ever since I was a child, I’ve liked science stuff, like growing plants, excavating ruins near my house, and programming on my computer. So I wanted to become a botanist, an archaeologist, or a computer engineer. When I was in high school, I figured out that I had the greatest aptitude for biology. I was especially interested in crop breeding. So I enrolled at Nagoya University’s School of Agricultural Sciences, and I’ve been trapped in the world of research ever since!


Q: What sorts of things make you think that research is interesting or rewarding?

I think it's really exciting and interesting when I can connect the dots in my mind and come up with a new idea for a study, or when I meet a fellow researcher and we hit it off and launch a new joint research project together. Actually conducting research means running into many failures and hardships, but when I'm working with students and collaborators and we pour a lot of effort and ingenuity into our work and finally produce our results, it's a thrilling and rewarding experience. It's particularly exciting when I get just the right color for my flowers or just the right taste for my fruits — that makes me want to scream, “I did it!”


Q: Your research team’s study on using genome-editing technologies to increase the sugar content of tomatoes by 30%, published in the journal Scientific Reports in November 2021, may make it possible to offer consumers sweeter tomatoes at more reasonable prices, right? Tell us more about this study. How is it revolutionary?

Genomes are said to be the blueprint of life. Genome editing is the technology of rewriting the information of genomes. We rewrote the genetic information that plays a role in suppressing excessive sugar storage in tomatoes by genome editing technologies and succeeded in breeding tomatoes that have 30% higher sugar content.


We are reaching the limits of what selective breeding can do to produce sweeter tomatoes. Farmers produce sweet tomatoes through a special method of giving them a limited amount of water. Not only is this method labor-consuming, but it also leads to dramatic decreases in fruit size and yield. By contrast, with our genome editing technologies, we can harvest sweet tomatoes of the same size and yield just through conventional cultivation. This is revolutionary in that it lightens the burden on farmers and makes it possible to provide sweet tomatoes to consumers at a reasonable price.


Q: How do you spend your days off? What do you do to recharge?

I like to recharge by going to hot springs out in nature, where I eat delicious local food and take a long and relaxing soak in the hot spring. Whether I'm traveling for work or pleasure, when I put myself in a new and different environment, it's like parts of my brain that are usually unused get activated. When I just sit on a train or soak in a hot spring, I can clear my head and connect dots in my mind that I normally wouldn't be able to connect. It inspires new ideas for my research and my work.


Q: Please tell us about an experience that you can only talk about now.

I was a shy child. When I was in elementary school, I was the kind of kid who just stared at my desk in embarrassment when my teacher called on me to answer a question. I thought that researchers just spent all their time working alone, so I figured that was the job for me. But in reality, if you teach at university, most of your work is to talk in front of people, giving lectures in front of many students and delivering presentations in front of large audiences at conferences and seminars. It was tough at first. But now, I enjoy having students and audiences understand what I tell them. Although I still get a bit of stage fright, talking in front of a crowd doesn't stress me out anymore.


Q: What are your goals and ambitions for the future?

We are now witnessing an amazingly rapid revolution in genome decoding, bioinformatics, and other technologies that reveal the mysteries of life, as well as innovative plant breeding technologies like genome editing. With these technologies, I want to unveil the wonders of flowers, vegetables, and fruits so as to create crops that can help enrich people's lives throughout the world.




 Reunion with former research colleagues at the University of Zurich, Switzerland




Name: Katsuhiro Shiratake

Department: Graduate School of Bioagricultural Sciences

Title: Associate Professor


Born in Tokyo and grew up in Fukuoka in Japan. He attended Nagoya University, where he graduated from the School of Agricultural Sciences in 1993 and the Graduate School of Bioagricultural Sciences in 1998, ultimately earning his doctorate in agriculture science. He became an Assistant Professor at the School of Agricultural Sciences in 1998 before assuming his current position in 2007. He was also engaged in research as a Visiting Associate Professor at the Institute of Plant Biology at the University of Zurich in Switzerland from 2003 to 2005.

His hobbies include travel. He backpacked around the world when he was a student, but his travels nowadays mostly revolve around hot springs in Japan.