Abstract
Exudate was collected fromRicinus communis L. cotyledons after cutting the hypocotyl. It contained high levels of sucrose and potassium, a low level of calcium, and a pH of approx. 7.5. After application of [14C] sucrose to the cotyledons, radioactivity could be recovered from the exudate, indicating that the exudate was derived from the phloem. Using data from a number of individual seedlings, correlations between loading rates of sucrose, translocation rates, and sucrose and potassium contents were analyzed. A positive correlation was found between the rate of sucrose loading and the rate of sucrose exudation, whereas a negative correlation existed between the contents of sucrose and potassium in the phloem.
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Vreugdenhil, D., Koot-Gronsveld, A.M. Characterization of phloem exudation from castor-bean cotyledons. Planta 174, 380–384 (1988). https://doi.org/10.1007/BF00959524
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DOI: https://doi.org/10.1007/BF00959524