Multiphasic Uptake of Sulfate by Barley Roots

Holmern, Kari; Vange, Marta S.; Nissen, P.

doi:10.1111/j.1399-3054.1974.tb03710.x

Cited by 26 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sulfhydryl reagents N-ethylmaleimide (10-5 M) and iodoacetamide (10-4 M) completely abolish transport (Table III), which is in agreement with the observations of other investigators using a variety of organisms (10,11,17,18). In the case of iodoacetamide a noninhibitory concentration (10-5 M) stimulated transport (Table III); this stimulation was always observed, but the amount of stimulation was extremely variable, ranging from 40 to 150%.…”

Section: Resultssupporting

confidence: 89%

“…Nissen and his coworkers (10,(19)(20)(21)26) reported that the uptake of sulfate by roots and leaf slices of barley is mediated by a single multiphasic mechanism. In rape two separate sulfate transporting systems have been proposed (23).…”

Section: Resultsmentioning

confidence: 99%

“…Sulfate transport has been studied in intact plants and plant parts (8,10,15,19,20,23,26) and cultured plant cells (6,24,25). Sulfate transport into tobacco cells cultured in liquid medium obeys Michaelis-Menten kinetics (6), is regulated by the intracellular sulfate pool (24), and is inhibited by dithiothreitol and CCCP' (25) (24) with one modification; washed cells were placed in a 1 25-ml Erlenmeyer flask containing 40 ml of M-1D medium, 0.4 ml of 5 mm Na235SO4 (2 ,uCi).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of Sulfate Transport in Cultured Tobacco Cells

Smith¹

1976

Plant Physiol.

View full text Add to dashboard Cite

Sulfate transport by tobacco cells (Nicotiana tabacum L. var. Xanthi) cultured in liquid medium was investigated.Transport was linear with time, had a sharp pH optimum between 6.5 and 7.5, and obeyed Michaelis-Menten kinetics. The Km varied within the range 2 x 10-5 M and 4 x 10-5 M and the maximum velocity was in the range 100 to 400 nanomoles per gram fresh weight-hour.Transport was inhibited more than 90% by 10-4 M sulfite, thiosulfate, metabisulfite, sulfide, selenate, and chromate, but was inhibited less than 40% by 10-3 M chloride, nitrate, or phosphate. Selenate was a competitive and sulfide a noncompetitive inhibitor of sulfate transport.The oxidative respiration inhibitors, azide and cyanide, uncoupling reagents, carbonylcyanide m-chlorophenylhydrazone (CCCP) and dinitrophenol, and the ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD) were all potent inhibitors of transport. Inhibition by CCCP was not prevented by preincubation of cells with dithiothreitol. Removal of CCCP from the transporting medium resulted in a partial resumption of transport, in contrast removal of DCCD had no effect.Sulfate transport was inhibited more than 90% by 10-4 M mercaptoethanol, dithiothreitol, or D-cysteine and was abolished by either 10-5 M N-ethylmaleimide or 10-4 M iodoacetamide. Removal of mercaptoethanol from the transporting medium resulted in a return to maximal rates of transport whereas when either N-ethylmaleimide or iodoacetamide were removed transport remained inhibited.N-ethylmaleimide (10-5 M) and iodoacetamide (10-4 M), which inhibited transport completely, induced the efflux of between 70 and 90% of the transported sulfate in 5 hours. Metabolite efflux was induced by the following compounds, which are listed according to their effectiveness, DCCD, CCCP, mercaptoethanol, and selenate. Increasing the concentration of an inhibitor, in excess of that required to inhibit transport 100%, increased the rate of nonspecific metabolite efflux from the cells.The concept that ion uptake in plants is an active, carriermediated process has been supported by numerous investigations (3,9,21). Sulfate transport has been studied in intact plants and plant parts (8,10,15,19,20,23,26) and cultured plant cells (6,24,25). Sulfate transport into tobacco cells cultured in liquid medium obeys Michaelis-Menten kinetics (6), is regulated by the intracellular sulfate pool (24), and is inhibited by dithiothreitol and CCCP' (25) (24) with one modification; washed cells were placed in a 1 25-ml Erlenmeyer flask containing 40 ml of M-1D medium, 0.4 ml of 5 mm Na235SO4 (2 ,uCi). and 10 mM HEPES, pH 7.CCCP and DCCD were dissolved in 95% ethanol and 0.2 ml added to 40 ml of transport medium prior to the addition of the cells. For comparison purposes 0.2 ml of 95% ethanol was added to all transport media used as controls in experiments with these compounds. This concentration of ethanol depressed transport rates between 25 and 35%, but had no effect upon the linearity of transport. The nature of this inhibition was not investiga...

show abstract

Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of Sulfate Transport in Cultured Tobacco Cells

Smith¹

1976

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Common characteri st ics i ncl ude (a) dependence of transport on energy coup 1 i ng which is susceptible to gradient uncouplers' and respiratory poisons (Deane and O'Brien, 1975;Holmern et aL.,1974;Jeanjean and Broda, 1977;Roberts and Marluf, 1971;Smith, 1976;Yamamoto and Segel, 1966), (b) size-specific competition of uptake by X04 analogs (X=Cr, Se, and Mo in decreasing order of effectivenessHDeane and O 'Brien, 1975;Pardee et al, 1966;Smith, 1976;Vange et aL., 1974), (c) effective inhibition by thiosulfate (Marzluf, 1970a;Roberts et aL., 1963;Smith, 1976;Utkilen et al, 1976;Vange et aL., 1974;Yamamoto and Segel, 1966), (d) reversible inhibition of uptake by sulfhydryl reagents Marzluf, 1974;Smith, 1976;Vallee and Jeanjean, 1968b), and (e) derepression of sulfate transport capacity during sulfur starvation (Deane and O'Brien, 1975;Jeanjean and Broda, 1977;Utkilen et aL., 1976;Yamamoto and Segel, 1966). …”

Section: Discussionmentioning

confidence: 99%

Assimilatory sulfur metabolism in marine microorganisms

Cuhel¹

1980

View full text Add to dashboard Cite

“…Transport obeys Michaelis-Menten kinetics over a limited concentration range (5,13). One of our objectives was to increase the sulfate concentration range to that used in kinetic studies of sulfate transport into intact plant tissues, where more complicated kinetics have been reported (6,12,15).…”

mentioning

confidence: 99%

Sulfate Transport in Cultured Tobacco Cells

Jones

Smith²

1981

Plant Physiol.

View full text Add to dashboard Cite

Sulfate Transport. Cells were harvested by vacuum filtration and washed with 50 ml 1% (w/v) sucrose. The washed cells (0.25 to 0.5 g fresh weight) were placed in a 125-ml Erlenmeyer flask containing 36 ml preincubation medium composed of 1% (w/v) sucrose, 0.5 mm CaCl2, and 5 mM bis-Tris-propane (pH 7). Usually cells were preincubated in the presence of Ca2' and the absence of sulfate for 4 h. Transport was initiated by the addition of 4 ml 0.5 mm Na2MSO4 (Amersham/Searle Corp., specific radioactivity used was in the range 0.04 to 0.18 Ci/mol). The flasks were stoppered with cotton plugs and placed on a rotary shaker (80 rpm) at 25 C for 1 h. At the end of the experiment, the cells were harvested by vacuum filtration, washed with 100 ml 0.5 mm Na2SO4, and placed in 10 ml Aquasol liquid scintillation fluid.

show abstract

Multiphasic Uptake of Sulfate by Barley Roots

Cited by 26 publications

References 25 publications

Characterization of Sulfate Transport in Cultured Tobacco Cells

Characterization of Sulfate Transport in Cultured Tobacco Cells

Assimilatory sulfur metabolism in marine microorganisms

Sulfate Transport in Cultured Tobacco Cells

Contact Info

Product

Resources

About