Nutrient transportation

[Terry Ellacott]

I am watching my amazon sword plant pearling and it is producing a single steady stream of tiny bubbles. I started to wonder how the excess oxygen from twenty leaves gets to the one point where it forms the bubbles . That started me wondering how the nutrients from the substrate are transported from the roots to the leaves in aquatic plants which cannot use transpiration. 

I did try looking it up on Google but soon lost the will to live. 

If anyone can give me any information on how these things work I would be very grateful. 

 

[darkG]

It seems to be mainly root pressure.

(Sometimes a single point stream of tiny bubbles means there is a wound, leaking oxygen - I don't think it's cause for alarm though.)

 

[gardenman]

Much like people, plants have veins and a circulatory system that moves stuff around inside of them. Plants breathe (absorb CO2 and exhale oxygen) through their stoma (kind of like out mouths and nose). Their circulatory system grabs the CO2 they've inhaled and moves it around the body of the plant to everyone who wants it and then picks up the oxygen those cells give back in exchange and takes it back to a stoma for discharge and to pick up more CO2 for the next go round. We breathe out through our mouth and nose, but the oxygen we breathe in goes throughout our body and the CO2 we exhale comes from all around our body, but it all comes and goes through our mouth. Our mouths/lungs and feet don't seem especially connected, but the circulatory system moves the stuff we need to where it's needed. With plants some stoma will take on the job of discharging the excess oxygen while others will look to absorb more CO2. Stoma can open and close, much like our mouths, and respond to outside and internal stimuli. (Light, CO2 levels, etc.) When we see the stream of oxygen bubbles, they're coming from an open stoma. Much like we can't hold out breath forever, plants can't keep the excess oxygen bottled up forever. They open a stoma and out it goes. Once that stoma is open it'll stay open until a reason comes along for it to close. (Darkness, lack of CO2, etc,) 

[darkG]

Underwater plants rarely have stomata though.

[gardenman]

17 minutes ago, darkG said:

Underwater plants rarely have stomata though.

The underwater plants that don't have stoma typically have surface cells that replicate the function of stoma. The end result is largely the same. 

[Terry Ellacott]

I find it surprising that so much oxygen is moving to one point to be expelled rather than each leaf expelling a small amount. 

I understand that transpiration moves substances from roots to leaves, and gravity and osmosis move things from leaves to roots in terrestrial plants. I struggle to see how these can work underwater. Do you know what the "pump" is that moves things about in aquatic plants, it seems very efficient to move all the oxygen from each leaf to that one point, or is the oxygen just diffusing through all the water within the plant until it reaches a weak point.