Transport in the Phloem

Nectar Production in Abutilon IV. Wate'r and Solute Relations

“…The single value obtained for the phloem sap concentration is similar to that reported for the phloem sap of a number of other woody species (Zimmermann 1960). It is interesting that the maximum rate of nectar secretion by isolated nectaries occurs in nectaries on about O· 4M sucrose (about the concentration in the phloem) and this is also the medium concentration when there is a transition from a two-phase to a one-phase nectar secretion pattern.…”

Sugar Gradients and Translocation of Sucrose in Detached Blades of Sugarcane

“…Supplying ATP to the cut end had no beneficial effect on translocation, but there is doubt as to whether any was absorbed. (28), (b) permeability is affected by viscosity (28), and (c) sieve tube semipermeability was shown by Zimmermann (34) (fig 2), is against the diffusion theory. Also, if diffusion were the mechanism, even activated diffusion, only more sucrose coming in the cut apex could reverse the polarity of translocation in the dark.…”

Carbohydrate translocation in raspberry & soybean

“…and the comprehensive treatment of the subject by Sw%vanson (10). In addition, Zimmermann (15,17,18) has reviewed the special aspect of carbohydrate transport in trees. One of the hypotheses propose(l in these andl other discussions, suggests that sucrose and sucrose-containing oligosaccharides are the major transport compounds in most higher plants.…”