Uptake and Transport of Sulphate in Wheat. Active and Passive Components

Kinetics of rubidium absorption & translocation by barley

“…Much evi(lence that ion accumlulatioln froml a bathing solution to shoots of plants is passive is basedl on the effect of traanspirationi on the appearance of the ionl in the shoots (18. 19., 23,29). The effect of transp)iration riate wN-as teste(l und{ler the experimental conditiolns (lescril)e(l undler mletlho(ds b1 var-ing tranispiration without varyiing ioln acctumiiulationi by roots.…”

“…The transport of ions from a bathing solution to the top of a plant has been described as a passive (7,8,18,19,22,23,28) and active (2,3,17,26,27) process. Brouwer (3) states that at least 70 to 85 % of the ions appearing in the tops of plants go through an active process, i.e., "owing to a mechanism controlled or started by metabolism lands into the transpiration stream".…”

Uptake of Dinitrophenol & its Effect on Transpiration & Calcium Accumulation in Barley Seedlings

“…In a recent review, Russell and Barber (19) concluded that ions are first actively transported into the stele of the root and that thereafter transpiration may or may not affect their rate of moovement to the shoot depending on the salt status of the root, the external ionic concentration, and the rate of transpiration. In contrast, Hylmo and his co-workers (12, 13,14,16), while acknowledging the existence of an active transport component, stress the importance of transpiration in the movemlent of ions to the shoot. Since the present work was conmpleted.…”

“…However, in view of the work of Epstein (7), Crafts (6), and others, it seems more plausible that Ca 1Received revised manuscript July 16,1962. 2 Presented at the Davis, Cal., meeting of the ASPP, The jars were wrapped in black paper and placecl in a growth chamber maintained at 25 C with 40 % relatve humidity andl a 16-hour light period of 1,000 ft-c.…”

Uptake and Metabolism of Sulfate by Chlorella. I. Sulfate Accumulation and Active Sulfate

“…Ani inidicatioln of the amounits of sulfate w-hich may le recovere(l fromii Clhlorella in tlle formii of nucleoti(le sulfate coipl)ounds by mieanis of p)erchloric acidl extraction and ad sorp)tioin oil Charcoal folloxve(l by elution and ionophoretic separation of the adsorbed comiipounds is given in (4,5,7) hypotheses of ion transport is that the anion does in fact exist within the cell in the ionic form behind a diffusion barrier, the initial passage of which is facilitated by a metabolic mechanism possibly involving conmbination with a carrier substance, or that outward diffusioni is in some way prevented by expenditure of metabolic energy.…”