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Hello, everyone. SCIEN-SPOT is a podcast that shines a spotlight on the latest scientific technology from Japan.
Your host is REN from SCIEN-TALK.
発光植物の進化
Have you ever imagined walking through a city at night and instead of street lights, the trees themselves were glowing?
It sounds like something out of a science fiction movie,
but this seemingly technology is actually becoming a reality thanks to a remarkable researcher in Japan.
So I will dive into the world of glowing plants developed by the professor at Osaka University
and explore the evolution of the light-emitting technology behind them.
First, why do scientists want to make cells and plants glow?
It's all about visualizing the dynamism of life, understanding what's happening inside the living cells.
Light acts like a label that helps us pinpoint where cells and proteins are located and how they move.
Historically, the most famous technique for making cells glow was using Green Fluorescent Protein, or GFP, discovered by Nobel Prize winner Dr. Osamu Shimomura.
GFP emits green light when exposed to blue light, known as excitation light.
This technology has greatly advanced biological research.
However, this excitation light can be harmful to cells, and observing them requires specialized microscopes.
That's where Professor Nagai focused his attention on bioluminescence,
the natural phenomenon where organisms like fireflies and mushrooms grow on their own.
Unlike fluorescence, bioluminescence doesn't require an external excitation light source.
The main drawback, however, was that bioluminescence is incredibly dim, less than 1,000 times as bright as fluorescence.
To overcome this significant challenge of dimness, the professors developed a groundbreaking method.
Their first creation was a technology called NanoLantern.
This involved cleverly fusing blue bioluminescent proteins,
derived from sea pansies with bright yellow fluorescence proteins, which was developed by another professor.
They engineered this fusion to allow FRET,
FRET means Forest Resonance Energy Transfer, to occur efficiently.
You can think of it like converting energy that would normally be released as heat into light.
光る植物の誕生
This fusion dramatically increased the brightness of cellular luminescence by over 10 times.
This breaking through made it possible to capture phenomena occurring on moving cells on a second-by-second basis.
Next, this team considered, can we make this even easier to use?
Even with NanoLantern, an artificially synthesized substrate called luciferin still needed to be added to the cells to make them grow.
So they isolated not only the bioluminescent protein genes,
but also the genes for the enzymes necessary to biosynthesize luciferin from naturally glowing mushrooms.
When these genes were introduced into tobacco plants,
the tobacco leaves and flowers began to grow brightly on their own, without any external additions.
This was truly the birth of glowing plants.
These glowing tobacco plants are bright enough to be photographed clearly with a smartphone camera,
and even slated for the exhibition at the Osaka Kansai Expo.
And the latest achievement, announced just recently, is the development of the 20-color bioluminescent protein.
発光色の技術革新
This builds upon the NanoLantern technology.
By cleverly linking, for example, two different fluorescent proteins, like green and yellow,
to a blue bioluminescent protein and then adjusting the efficiency of FRET,
they successfully created a wide array of glowing colors.
It's almost like digitally selecting color codes,
really changing the mixing ratio of the three primary colors of light, red, green, and blue.
This innovation has led to the creation of 20 different colors of glowing proteins,
making it possible to observe multiple cells simultaneously, each glowing in a different hue.
And this luminescence technology isn't just confined to basic research.
The ultimate goal is the Glowing Tree Project,
applying this technology to create glowing trees for street lights.
Since the light is produced through a chemical reaction, absolutely no electricity is required.
This could potentially reduce electricity consumption and carbon dioxide emissions,
while also contributing to urban greening.
It's a totally game-changing technology that could offer a new solution to climate change.
生物発光植物の可能性
While they're not yet bright enough for full street illumination,
the team aims to achieve practical lighting levels within the next 10 years.
So how was today's science booth?
This technology is very impressive and I'm looking forward to seeing these bioluminescent street trees near my home or everywhere.
This podcast is broadcasted daily on weekday morning in both Japanese and English.
I hope today's discovery has changed how you view your surroundings, even just a little.
I'd love for you to listen to the podcasts and post your notes and thoughts with the hashtag sciencebooth.
See you next time.
