Premium
Measurements of pH, sucrose and potassium ions in the phloem sap of castor bean ( Ricinus communis ) plants
Author(s) -
Vreugdenhil Dick,
KootGronsveld Elly A. M.
Publication year - 1989
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1989.tb05657.x
Subject(s) - phloem , ricinus , exudate , apex (geometry) , potassium , sucrose , botany , shoot , chemistry , biology , horticulture , food science , organic chemistry
The composition of phloem sap, sampled at different heights along, the stem of castor bean ( Ricinus communis L. cv. Gibsonii) plants, was determined. A gradient in pH was observed; the highest pH values occurred near the shoot apex, decreasing towards the base of the stem. The sucrose content of the exudate exhibited a similar gradient. The concentration of potassium ions was highest near the uppermost, full‐grown leaves, decreasing towards the apex and the base of the stem. The importance of these findings for the understanding of phloem translocation and unloading is discussed.