Coupling of solute transport and cell expansion in pea stems.
As cells expand and are displaced through the elongation zone of the epicotyl of etiolated pea (Pisum sativum L. var Alaska) seedlings, there is little net dilution of the cell sap, implying a coordination between cell expansion and solute uptake from the phloem.  Using [14C] sucrose as a phloem tracer (applied to the hypogeous cotyledons), the pattern of label accumulation along the stem closely matched the growth rate pattern:  high accumulation in the growing zone, little accumulation in nongrowing regions.  Several results suggest that a major portion of phloem contents enters elongating cells through the symplast.  We propose that the coordination between phloem transport and cell expansion is accomplished via regulatory pathways affecting both plasmodesmata conductivity and cell expansion.
Schmalstig
J G
JG
Department of Biology, Pennsylvania State University, University Park 16802, USA.
Cosgrove
D J
DJ
D001692:Biological Transport; D002241:Carbohydrates / Q000493:pharmacokinetics*; D002462:Cell Membrane / Q000378:metabolism; D005632:Fructose; D005947:Glucose / Q000493:pharmacokinetics; D018698:Glutamic Acid / Q000493:pharmacokinetics; D009994:Osmolar Concentration; D018532:Pisum sativum / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D018547:Plant Stems / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D011188:Potassium; D013395:Sucrose / Q000493:pharmacokinetics; D013997:Time Factors
D002241:Carbohydrates; D005632:Fructose; D018698:Glutamic Acid; D013395:Sucrose; D005947:Glucose; D011188:Potassium