Phloem transport (1 Viewer)

[keeski]

Hey guys,
I just came across symplastic loading and apoplastic loading in one of my texts and I'd never even heard of it before- can someone please explain to me? We never covered it in class, we just got told that the movement is from source to sink/ pressure flow. Help would be greatly appreciated, thankyou!

 

[wavess]

Well from what I know, the source path sink theory involves
a) Loading at the source (involving)
i- Symplastic loading =where sugars and other nutrients move into the cytoplasm from the mesophyll cells, then into the sieve elements through the plasmodesmata
ii - Apoplastic loading =where sugars and ther nutrients move along the cell walls until they reach the sieve tube. They then cross the cell membrane by active transport.
hope that kind of helps

 

[keeski]

yes it does, but I think i'm going to have to do a bit more research thankyou!