Phloem transport, solute flux and the kinetics of sap exudation in Ricinus communis L. Export

@article{citeulike:4295226, abstract = {The osmotic characteristics of phloem-sap exudation were examined in soil-grown and watercultured plants of Ricinus communis L. Prolonged exudation occurred from bark incisions in water-cultured plants. Fresh incisions caused large alterations in solute flux, but phloem-sap solute potential ?s changed by less than ±8\% over a period of 7 h. This was associated with a constancy in the levels of sucrose and K+, the principal solutes in the sap. Studies with foliar-applied tracers and leaf-excision experiments suggested that exudation was maintained by solute loading from mature leaves. A wide range of mass transfer values through the phloem was found, these being a function of exudation rate. We consider that the exudation process possesses essentially similar characteristics to phloem transport in the intact plant. The way in which bark incisions bring about large changes in solute flux is discussed in terms of the physical properties of the sieve-tube system.}, author = {Smith, J. A. C. and Milburn, John A.}, citeulike-article-id = {4295226}, citeulike-linkout-0 = {http://dx.doi.org/10.1007/BF00385439}, citeulike-linkout-1 = {http://www.springerlink.com/content/k14162r27mnt3388}, day = {1}, doi = {10.1007/BF00385439}, journal = {Planta}, keywords = {exudation, solute}, month = {February}, number = {1}, pages = {35--41}, posted-at = {2009-04-09 18:53:47}, priority = {2}, title = {Phloem transport, solute flux and the kinetics of sap exudation in Ricinus communis L.}, url = {http://dx.doi.org/10.1007/BF00385439}, volume = {148}, year = {1980} }

TY - JOUR ID - citeulike:4295226 L3 - citeulike-article-id:4295226 N2 - The osmotic characteristics of phloem-sap exudation were examined in soil-grown and watercultured plants of Ricinus communis L. Prolonged exudation occurred from bark incisions in water-cultured plants. Fresh incisions caused large alterations in solute flux, but phloem-sap solute potential ?s changed by less than ±8% over a period of 7 h. This was associated with a constancy in the levels of sucrose and K+, the principal solutes in the sap. Studies with foliar-applied tracers and leaf-excision experiments suggested that exudation was maintained by solute loading from mature leaves. A wide range of mass transfer values through the phloem was found, these being a function of exudation rate. We consider that the exudation process possesses essentially similar characteristics to phloem transport in the intact plant. The way in which bark incisions bring about large changes in solute flux is discussed in terms of the physical properties of the sieve-tube system. IS - 1 JF - Planta EP - 41 TI - Phloem transport, solute flux and the kinetics of sap exudation in Ricinus communis L. VL - 148 SP - 35 KW - exudation KW - solute AU - Smith, JAC AU - Milburn, John PY - 1980/02/01/ UR - http://dx.doi.org/10.1007/BF00385439 ER -