Red root tips

[Cruiser]

Western hemlock roots growing strongly in DF bark.



Roots are shallow and more concentrated in areas beneath osmocote.




Collected June 2024

 

[nuttiest]

Is it anthocyanins making that color or something else? Looks like it would be used for dye.

 

[Cruiser]

Is it anthocyanins making that color or something else? Looks like it would be used for dye.

I believe so, though I’m not sure exactly what it indicates.
The red is mostly present in longer “searching” roots, not the fines.
My working theory is that it indicates very strong growth. What one might see in aggressive roots pushing through rotting wood.

 

[Wires_Guy_wires]

Yes, it's likely to be some kind of internal compound that prevents rapid oxidation of the highly active root tip. It's burning energy like crazy in this state, especially at the tip, so the plant makes some protective molecules to stop it from burning too hard - and probably also to preserve hormones instead of letting them break down.
I've seen this hundreds if not thousands of times in plants, mostly in tissue culture settings where the substrate was transparant agar.

For fun I investigated a bunch of those roots under a microscope and there was nothing out of the ordinary about them. The red leaves a smear on paper, but it turns brown pretty fast when exposed to air.

In some cases, it's bacteria that have turned commensal inside the root tip cap. But those tend to look more matte and slightly more pink.

 

[Cruiser]

Fasci

Yes, it's likely to be some kind of internal compound that prevents rapid oxidation of the highly active root tip. It's burning energy like crazy in this state, especially at the tip, so the plant makes some protective molecules to stop it from burning too hard - and probably also to preserve hormones instead of letting them break down.
I've seen this hundreds if not thousands of times in plants, mostly in tissue culture settings where the substrate was transparant agar.

For fun I investigated a bunch of those roots under a microscope and there was nothing out of the ordinary about them. The red leaves a smear on paper, but it turns brown pretty fast when exposed to air.

In some cases, it's bacteria that have turned commensal inside the root tip cap. But those tend to look more matte and slightly more pink.

Fascinating. So if the red is anthocyanin, it makes sense in regard to the oxidation.

Does this process happen elsewhere in a tree’s anatomy? Some of my noble fir seedlings have a reddish hue to opening buds. They normally are brown-green.

 

[Wires_Guy_wires]

Does this process happen elsewhere in a tree’s anatomy

Yep, any highly active piece. Especially in seedlings and younger plants this color can be fireworky ranging from pink to red or deep purple.

Some of the wild communis junipers around here turn entirely purple in winter, same molecules, same mode of action, but a different trigger.

Some herbaceous plants can turn black if they stay photosynthetically active while temperatures drop.