Pop Quiz On Living Soil

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jumpincactus

jumpincactus

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There has been and is a wealth of information on soil science/living soil here at the Farm. With that said I thought it would be cool to have a little fun.

Lets start with a fact that got me going on the subject matter for the quiz. Did you know that at the growth tip of a plants root the pressure can be as much as (>7kg/cm2 or ~100 psi)? This of course helps the root plow/bore thru the soil seeking nutes. There is a root "exudates" that contain a substance called" mucilage" that acts as a lubricant to allow the root tip to pass thru the soil with the root tip pressure. Mucilage is made up of protiens and polysaccharides. These "exudates" are passively released by the "root cap" and epidermal cells.

Ready for the drum roll???? Ok, now that I have you bored to death do a toke and here is the question.

Name 3 other processes that " mucilage" is responsible for in the rhizosphere? Number 1 was a root lubricant.

First one to get all 3 answers correct a secret prize from my secret prize stash bag that's kept in a secret place that was shown to me by a 105 year old mountain Sage.

No, I cannot tell you otherwise it wouldn't be a secret. Suffice to say, I will probably be looking in to my mystery fire bag. I will have to be holding the magic pink beans at the time to properly align me with the treasures inside. That's the only clue you get.

You will have to trust in me in as much as I have the source I used for this information, this is the source I will use to determine the winner. In deciding who got the 3 right I would ask that you PM me your source and at the contest end I will post my source so you all know I was playn fair. Thats the tough part of this quiz, as I don't know how many other sources are out there with varying degrees of what other researchers feel mucilage can do....... Thats the rub.......... Better yet, I will PM @Seamaiden and send her the link for my source. This way you will all know I'm doing you right.


Peace
 
Toaster79

Toaster79

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- presence of air-filled gaps between soil and roots

-water repellence in the rhizosphere caused by drying of mucilage around the soil particles

-water accumulation in the rhizosphere due to the high water-holding capacity of mucilage
 
Muckman420

Muckman420

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mucilages of both plant and bacterial origin can contribute to the adhesion and cohesion of maize rhizosheaths.

The root cap transmits information through the mucilage.

As cells of the cap reach the periphery, they separate as a population of uniquely differentiated, metabolically active, border cells encased within the mucilage, forming a living interface with the soil.
 
jumpincactus

jumpincactus

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Ok sorry for the wait. guys and gals. I had a small crisis with a garden I am helping tend. That said, I am going to need help determining the results. I dont think anyone hit all 3 responses but a few came dang close. I will post my source and highlight and underline the responses I was looking for. If you folks would double check me to assure my results are correct.

http://www.nature.com/scitable/knowledge/library/the-rhizosphere-roots-soil-and-67500617

Feel free to check out the link and whole article as it is fascinating stuff.

Here is a para with the results I was looking for. The 3 answers I was hoping for was 1. dessication 2. nutrient uptake assitanse, 3. Helping form soils aggregates which lends to overall better soil structure.

Should anyone feel they actually hit it please throw your response out and we can go over it. Thanks for all that played!!!

Roots exert a tremendous amount of pressure (>7kg/cm2 or ~100 psi) at the growing root tips in order to push their way through the soil. Helping to lubricate and protect the root during growth, root cap and epidermal cells secrete mucilage, a viscous, high molecular weight, insoluble, polysaccharide-rich material. Beyond lubrication, the mucilage also provides protection from desiccation, assists in nutrient acquisition, and most notably binds soil particles together forming aggregates which improve soil quality by increasing water infiltration and aeration. Also serving to protect the root tip, cells lining and capping the root meristem are programmed to release (slough-off) which helps to reduce frictional forces that would otherwise damage the root (Bengough and McKenzie, 1997). Interestingly, the cells that are sloughed off continue to function and secrete mucilage for several days and have been shown to attract beneficial microorganisms, serve as "bait" for root pathogens, and sequester toxic metals (e.g. Al3+) (Hawes et al., 2000).

Root exudates include both secretions (including mucilage) which are actively released from the root and diffusates which are passively released due to osmotic differences between soil solution and the cell, or lysates from autolysis of epidermal and cortical cells (Figure 4). The organic compounds released through these processes can be further divided into high and low molecular weight (HMW and LMW, respectively). By weight, the HMW compounds which are those complex molecules that are not easily used by microorganisms (e.g. mucilage, cellulose) make up the majority of C released from the root; however, the LMW compounds are more diverse and thus have a wider array of known or potential functions. The list of specific LMW compounds released from roots is very long, but can generally be categorized into organic acids, amino acids, proteins, sugar, phenolics and other secondary metabolites which are generally more easily used by microorganisms. The cocktail of chemicals released is influenced by plant species,edaphic and climactic conditions which together shape and are shaped by the microbial community within the rhizosphere. There is still very little known about the role that a majority of the LMW compounds play in influencing rhizosphere processes. A growing body of literature is beginning to lift the veil on the many functions of root exudates as a means of acquiring nutrients (e.g. acquisition of Fe and P), agents of invasiveness (i.e. allelopathy) or as chemical signals to attract symbiotic partners (chemotaxis) (e.g. rhizobia and legumes) or the promotion of beneficial microbial colonization on root surfaces (e.g. Bacillus subtilis, Pseudomonas florescence) (Bais, Park et al. 2004).
 
Muckman420

Muckman420

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I say we all did great, roots a tremendous things, even our circular system works like roots.
 
jumpincactus

jumpincactus

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Yes indeed. @Muckman420 it was a tough one due to so many sources of research and info.
 
Muckman420

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I would imagine mucilage has more than 3 important functions in the rhizosphere, I would imagine it would also act as a bonding agent to hold the plant more firmly in the soil among many many vital processes that only a plant could speak of ;)
 
jumpincactus

jumpincactus

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@Tnelz I do believe I will. If you all think its a cool idea. Just thought it would be a good way to get folks to really dig and do some research and have a little fun while at it. I will check with @Seamaiden to see if this will be ok.
primordial said:
Mucilage has a role in phenotypic plasticity

http://en.m.wikipedia.org/wiki/Phenotypic_plasticity

^^^^^^^^^^main reason why my phenos always differ from the crews.....makes building your own soil much more exciting.
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Most excellent @primordial See this is why I thought this is a cool exercise. I have always wondered what "plasticity" was in relation to plants. Now thanks to Primordial I have a better understanding. Thank you primordial!!!
 
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