Why is phloem unloading passive in young leaves, but active in roots of a sugar beet plant?

+4 votes

Young leaves store sucrose. Roots immediately use unloaded sucrose, creating a concentration gradient.

Young leaves are closer to sources than roots.

Roots must actively accumulate sucrose to avoid losing it to the surrounding soil.

Young leaves immediately use unloaded sucrose, creating a concentration gradient. Sucrose builds up in storage cells in roots.

 
asked Dec 30, 2012 in Biology by anonymous
    

1 Answer

+1 vote

 

Young leaves immediately use unloaded sucrose, creating a concentration gradient. Sucrose builds up in storage cells in roots.

 

answered Dec 30, 2012 by JPx ~Expert~ (379 points)



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