[Wet Thumb Forum]-Carbohydrate uptake by plants?

[codeflag99]

So far, all the plant biology refernces I've found only talk about mineral and gas uptake by plants. However, the existence of organic carbon supplements for both aquarium plants and hydroponics suggests that plants are able to absorb other compounds from their environment and use them.

I'm having trouble finding references on the 'net about this mechanism (if it actually occurs).

I think I have tried every combination of terms in google searches.

The only references I have found repeat the information in Ms Walstad's book, that organic carbon added to the water will be converted by other organisms to C02, then taken up by the plants.

I did find the following:
"When organic matter is consumed and digested by microorganisms (primarily bacterium), it is broken down and released as enzymes of proteins, starches, vitamins, hormones and other such metabolites. Some of these compounds can be taken up into the plant and stored, or selectively utilized by the plant for metabolic functions. These processes of plant chemistry are very complex electrochemical interactions which take place in a series of stages, in an infinite chain of events not yet fully defined by science. The end result of all of this is to provide pure inorganic elements which are the building blocks of all life."
(ref)

It still implies everything gets broken down before it is used by the plant.

Does anyone know of any references to this in botany literature, or are these products just adding food for the bacteria?

George

[codeflag99]

So far, all the plant biology refernces I've found only talk about mineral and gas uptake by plants. However, the existence of organic carbon supplements for both aquarium plants and hydroponics suggests that plants are able to absorb other compounds from their environment and use them.

I'm having trouble finding references on the 'net about this mechanism (if it actually occurs).

I think I have tried every combination of terms in google searches.

The only references I have found repeat the information in Ms Walstad's book, that organic carbon added to the water will be converted by other organisms to C02, then taken up by the plants.

I did find the following:
"When organic matter is consumed and digested by microorganisms (primarily bacterium), it is broken down and released as enzymes of proteins, starches, vitamins, hormones and other such metabolites. Some of these compounds can be taken up into the plant and stored, or selectively utilized by the plant for metabolic functions. These processes of plant chemistry are very complex electrochemical interactions which take place in a series of stages, in an infinite chain of events not yet fully defined by science. The end result of all of this is to provide pure inorganic elements which are the building blocks of all life."
(ref)

It still implies everything gets broken down before it is used by the plant.

Does anyone know of any references to this in botany literature, or are these products just adding food for the bacteria?

George

[codeflag99]

I also found this:

http://128.252.223.112/posts/archive...7607.Bt.r.html

"Generally, intact plant roots cannot absorb sugars in appreciable amounts and
use them in metabolism. Bits of plant tissue in sterile culture do require an
external sugar supply."


Aquatic plants can absorb through structures other than roots. Would this make a difference?

[codeflag99]

Don't you just hate it when you answer your own questions in public.

"Rice plants also have the ability to take up exogenous betaine aldehyde (BA), the substrate for BADH, through their roots, converting it to GB, with resultant enhanced tolerance of plants to salt stress."

Compatibility of glycinebetaine in rice plants: evaluation using ...

I would still like to hear other people's thoughts on this.

Thanks,

George

[graham1212]

i have no experience or knowledge of this but from reading the quotes it sounds to me like this is simply a description of what occurs in a tank when the bacteria is keeping everything clean and healthy. Whatever your fish dont eat eventually decays and ends up being broken down by the bacteria. isn't that "organic matter [that] is consumed and digested by microorganisms"? Not sure if im making sense but that leads me to believe these products are more marketing than anything.

if you can keep your plants healthy by adding fertilizers that are already prepared for your plants, wouldn't that be better than adding something that will first have to be processed by bacteria anyway?

sorry if i missed something or am way off...

graham

[dwalstad]

Fishfood is a wonderful fertilizer. It contains all nutrients that plants need. It is cheap and easy. The slow release of fertilizer insures a stable ecosystem. And your fish will love you for feeding them well and letting the excess feed the plants.

Limiting the fishfood input and then dumping in plant fertilizers doesn't make any sense to me.

The only reason I see for adding plant fertilizers is if you have CO2 injection. In this instance, where carbon no longer limits plant growth, you need to add more of the other nutrients. That's why CO2 injection forces you into an artificial situation.

There are many other forums that deal with artificial setups.