The Relationship between Transport of Individual Elements and Dry Matter from the Cotyledons of Pisum sativum L.

The transport of dry matter, nitrogen, potassium, phosphorus,magnesium and sodium from the cotyledons of pea seedlings wasmeasured over a growth period of 4 weeks. A linear relationshipbetween the export of each element and dry matter was observedthroughout the experiment, and it was shown that when a certainproportion of the dry matter available for transport had beenexported the same proportion of the amount of each of the elementsavailable for transport had also moved out of the cotyledons.It is concluded that the movement of an individual solute fromthe cotyledons is controlled by a solute potential gradientexisting between the source and sink.