I was contacted by mr. Masaaki (associate professor Biological Sciences, Hokkaido University) about a research he did on techniques we (bonsai fans) have been using for ever - pruning roots during repotting - but now with scientific approach. Interesting read - I was thinking we could discuss it here?

- What is new for you reading this work?
- What else would you want to have researched?

(opening the pdf seems to be possible by clicking right next to the paperclick.. )

It is going to take some time for me to read it, and a lot longer to understand. I will await with interest what others have to say,
Geoff.

Oscar wrote: (opening the pdf seems to be possible by clicking right next to the paperclick.. )

OK, I have just managed to access the link (difficult...), THANKS!
I am very much interested in reading it.

"When part of the root system is removed by root pruning, the plants are able to regenerate a new root system with a smaller size and more branches (Wang et al. 2014). This new root system provides an efficient intensive production system with reduced vegetative growth (by reducing the flow of nutrients, water and hormones from root to shoot), which led to the promotion of solar radiation interception, increased flower buds, more regular production (Rademacher 2004, Vercammen et al. 2005, Rodrı´guez-Gamir et al. 2010, Carra et al. 2017), as well as the production of better quality fruit with smaller size, firmer fruit, more soluble solids content and less pre-harvest drop (Schupp and Ferree 1987, Ferree 1992, Carra et al. 2017)."

So far, so good!

Yes we know that, but it was a long article to say what you just said in a few lines.

But the focal point of the article (which I found very interesting) is to determine what causes this response, genetically.
The conclusion is pretty clear:
"In this study, we provide a model for root cutting-induced auxin biosynthesis through primarily the activation of YUC9 and other YUC family genes. This results in the elevation of the endogenous auxin level that induces PAT-related gene expression and enhances PAT activity before activating downstream auxin signaling genes and inducing RCN.
This model clarifies a previously unknown link between
root cutting and YUC9 induction. While the signal activating
YUC9 and regulating the response to root cutting is yet to be
characterized, it is plausible that this signal is strongest at the
cut end and spreads upward to the whole root. Further inves-
tigations are necessary to reveal the missing link between the
cut-induced signal and the activation of YUC-mediated auxin
biosynthesis."

Oscar wrote: What else would you want to have researched?

While the "missing link" is not determined, I would like to see a series of tests to know how many times a root system can be pruned and the time lapse among prunings.
As a note:
There are some bonsai people that cut the tap root of Pine seedlings not only once, but three times to promote Lateral Rooting (LR on the article above).

I need to print this to read such long article

Just downloaded the .PDF file (harder than I thought it was by the way :pinch: ) and I agree with Geoff... It´s gonna take me a while for a full read and a better understanding. But in any case, great scientific material. I love that stuff.

Alain

I am trying to get it on my iPad while I read this but cant get the file downloading..?