Evidence for the Uptake of Sucrose Intact into Sugarcane Internodes

Lingle, Sarah E.

doi:10.1104/pp.90.1.6

Cited by 48 publications

(45 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…SA). This pattern was similar to uptake characteristics in other plant tissues (21) and cells (10 (14). Additional evidence for uptake without extracellular hydrolysis is that 1 '-fluorosucrose, a synthetic analog which is hydrolyzed by invertase at a rate 4200 times slower than sucrose (20), was taken up with a magnitude only slightly lower than sucrose (Fig.…”

Section: Sucrose Uptake Into Stem Sectionssupporting

confidence: 48%

Coupling of Solute Transport and Cell Expansion in Pea Stems

Schmalstig

Cosgrove²

1990

Plant Physiol.

View full text Add to dashboard Cite

Cells located in the elongation zone of stems and roots expand considerably before they are displaced from the growing zone, yet they exhibit little net dilution. For instance, in maize roots the cell sap osmotic pressure is uniform throughout the growth zone (22) and in pea epicotyls there is only a slight decrease (from 9.2-8.3 bar) in the growing region (4). Thus, the rate of unloading from the phloem (a major source of osmoticum in these tissues) appears to be closely coordinated with the local expansion rate.In contrast to the observations on intact plants, excised segments often exhibit considerable dilution during growth (23). Likewise in seedlings from which cotyledons were excised, growth resulted in dilution ofthe cell sap (18). Evidently the usual coupling between expansion and solute uptake can be broken, and cell expansion can still take place despite reduction or blockage of normal solute import.The nature of the coupling between cell expansion and import of phloem solutes depends on the pathway and the mechanism of exit of solutes from the phloem and entry into expanding cells. A pathway through the apoplast is indicated in mature stems (12) and roots (27) Every 20 min after addition, 10 ,uL of distilled water was spread over the cotyledon surfaces to keep the L-glucose solution wet. Fluorescein as the sodium salt was added as a 1.0% solution in a 1.5% agar block (5 x 5 x 2 mm) to the cotyledon surfaces cut as for L-glucose addition. All transport experiments were done in a box kept at 100% RH to reduce transpiration.After 1 h for sucrose and 2 h for other compounds, the epicotyl was cut into sections consisting of the plumule and hook and pieces from 4 to 60 mm ( Fig. 1)

show abstract

Section: Sucrose Uptake Into Stem Sectionssupporting

confidence: 48%

Coupling of Solute Transport and Cell Expansion in Pea Stems

Schmalstig

Cosgrove²

1990

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Tissue slices were then incubated at 28°C in airtight containers (500 mL) on a rotary-shaking incubator at 175 rpm for 5.5 h. The '4C0, evolved was sampled from the KOH in the center well. The tissue slices were then washed for 30 min in 15 mL of 25 mM K-Mes (pH 5.7) containing 250 miv mannitol and 1 mM CaC1, to remove apoplastic label as described by Lingle (1989). Thereafter, the tissues were frozen in liquid nitrogen.…”

Section: ' ' C Labeling Of Lnternodal Tissuementioning

confidence: 99%

“…lB), those internodes were selected for carbon partitioning and metabolite analysis. Since both SUC (Lingle, 1989) and the two reducing monomers, Glc and Fru (Sacher et al, 1963;Glasziou and Gaylor, 1972;Batta and Singh, 1986), can be taken up by sugarcane culm tissue, the extent of carbon partitioning in the sink tissues was investigated by independently supplying tissue slices with a11 three of these sugars uniformly labeled.…”

Section: Carbon Partitioningmentioning

confidence: 99%

“…Transverse sections (1.0-2.0 g) of internodal tissue, spanning the core, mid-internodal, and peripheral internodal regions, were excised, sliced (approximately 0.5 mm in diameter), and washed according to the method of Lingle (1989). [U-14C]Suc, [U-14C]Glc, and [U-14C]Fru (2.0 GBq mmol -I) were independently supplied to tissues in 2 mL of 25 mM K-Mes (pH 5.7) containing 250 mM mannitol.…”

Section: ' ' C Labeling Of Lnternodal Tissuementioning

confidence: 99%

“…Knowledge about carbon partitioning between different cellular constituents in sugarcane culm tissues is limited to partitioning within the sugar pool (Sacher et al, 1963;Batta and Singh, 1986;Lingle, 1989). In sugarcane cellsuspension cultures, increased carbon partitioning into SUC is at the expense of both respiration and structural material under nitrogen-limiting conditions (Veith and Komor, 1993).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Carbon Partitioning during Sucrose Accumulation in Sugarcane Internodal Tissue

1997

View full text Add to dashboard Cite

l h e temporal relationship between sucrose (Suc) accumulation and carbon partitioning was investigated in developing sugarcane internodes. Radiolabeling studies on tissue slices, which contained Suc concentrations ranging from 14 to 42% of the dry mass, indicated that maturation coincided with a redirection of carbon from water-insoluble matter, respiration, amino acids, organic acids, and phosphorylated intermediates into SUC. It is evident that a cycle of Suc synthesis and degradation exists in all of the internodes. l h e decreased allocation of carbon to respiration coincides with a decreased flux from the hexose pool. 60th the glucose and fructose (Fru) concentrations significantly decrease during maturation. The phosphoenolpyruvate, Fru-6-phosphate (Fru-6-P), and Fru-2,6-bisphosphate (Fru-2, 6-P,) concentrations decrease between the young and older internodal tissue, whereas the inorganic phosphate concentration increases. lhe calculated mass-action ratios indicate that the ATP-dependent phosphofructokinase, pyruvate kinase, and Fru-l,6-bisphosphatase reactions are tightly regulated in all of the internodes, and no evidence was found that major changes in the regulation of any of these enzymes occur. l h e pyrophosphatedependent phosphofructokinase reaction is in apparent equilibrium in ali the internodes. Substrate availability might be one of the prime factors contributing to the observed decrease in respiration.

show abstract