9/9
Huge thanks to all collaborators! Special thanks to Prof. Hidehiro Fukaki (Kobe Univ.) — his lab's imaging setup was essential. And to Dr. Takaaki Yonekura @monera-kingdom.bsky.social, a former senior whose modeling directly supported our conclusions.

8/n
This work is the culmination of 7.5 years of research, starting from my undergraduate days.
Deep thanks to my supervisor Prof. Yuki Kondo @ykondolab.bsky.social for unwavering support.

7/n
This means:
💡 Cytokinin is not just a generic growth signal —
It’s a switch that creates stem cells specifically for radial growth.

6/n
So what does cytokinin actually do during this peak?
It induces and activates stem cells.
Before the CRM, cells can’t directly differentiate to xylem or self-renew. After the CRM, they gain both abilities.

5/n
In Arabidopsis roots, cytokinin response imaging revealed something surprising:
A clear but transient peak of cytokinin signaling — which we called the cytokinin response maximum (CRM) — appears.
2–3 days later, radial growth begins.

4/n
Using a vascular cell induction system called VISUAL, combined with single-cell transcriptomics and luminescence imaging, we found something else:
Cytokinin doesn't just boost division — it promotes the transition of dormant procambial cells into active cambial stem cells.

3/n
Cytokinin was already known to be important for radial growth, but mostly thought to just promote cell division.
We questioned this assumption.

2/n
In many plants like trees, bifacial cambial stem cells drive radial growth by dividing actively.
Before that, they exist as inactive procambial cells — waiting in a dormant state.