Tuesday, August 28, 2012

The subtlety of the amazing Bacillis subtilis

Hello everyone.  I hope you are well.  

Have you noticed that we are about to have the Labour Day weekend?  How did that happen?  Have you been gardening?  I have, and also doing some reading.

We gardeners who observe plants, learn about plants and soil, labour in and love our gardens sometimes begin to think we are "on top of things" or understand what is happening in that realm.

And then we run across a study like the one below, and are humbled by the complexity of the life-web that supports our gardens and us.

Researchers led by Prof. Harsh Bais, at the University of Delaware, have published a study of how the bacterium Bacillus subtilis, which lives in the soil, makes a connection with plant hormones, which then signal plant leaves, stems, and petals to close stoma when there are harmful pathogens trying to enter.  This stops pathogens from entering the plant and becoming a systemic stressor (possibly killing the plant).

How cool is that, eh?!

Interesting too is that drought conditions can also start the sequence between the soil born bacterium, plant hormones and stoma closure.

The research used a modest little plant, mouse eared cress (Arabidopsis thaliana), which looks like a "weed" of the sort we'd take out of our gardens, but which is probably welcome in a healthy meadow mix of plants for animal fodder.

Of several soil bacteria tested (of the very many that there are!), the researchers determined that only the Bacillis subtilis triggered the beneficial reaction sequence that occurs in the soil plant web. 

Phys.org reports that the study underscores "both the importance of root-based processes in plant defense and the potential for bolstering plant immunity naturally through the emerging field of probiotics."  ("Probiotics" are "live microorganisms that are thought to be beneficial to the host organism."*)

In other words, do all you can to encourage healthy soil so you'll have healthy plants.

In Prof. Bais' words: "... there is increasing commercial interest in inoculating crop seeds with beneficial bacteria to reduce pathogen infection. 'Just as you can boost your immune system, plants also could be supercharged for immunity.'"

I think of the soil web as "wholistic" in the sense of there being many, many parts which are together greater than the sum of the individual parts.  I also have great respect for the abilities and detail-orientation of people in the sciences.  Balancing the "whole" and the detail is an ongoing dance.

Here, a researcher spends time separating out many factors (soil bacteria), finds only one that triggers a reaction (and admits to only knowing 5% overall of what the one does) and then wonders what place this one factor might play in treatment application for crop betterment.

Is it just our human nature to be awed by the small amazing things we can discover, and to hope that the one small thing can be applied to the larger scope difficulties we try so hard to solve?

You might want to read the study summary and have a think on these matters yourself.

Wishing you healthy soil, new discoveries, and happy gardening!

Why's Woman

Researchers show how probiotics boost plant immunity
August 27, 2012 by Tracey Bryant                 Physics News website website
The article has video and micrograph images of what happens

Adabidopsis thaliana, mouse eared cress - Wikipedia entry - http://en.wikipedia.org/wiki/Arabidopsis_thaliana

No comments: