- Title
- Sugar retrieval by coats of developing seeds of Phaseolus vulgaris L and Vicia faba L
- Creator
- Ritchie, Raymond J.; Fieuw-Makaroff, Sabine; Patrick, John W.
- Relation
- Plant and Cell Physiology Vol. 44, Issue 2, p. 163-172
- Publisher Link
- http://dx.doi.org/10.1093/pcp/pcg022
- Publisher
- Oxford University Press
- Resource Type
- journal article
- Date
- 2003
- Description
- Influxes of glucose, fructose and sucrose were characterised for coat cells of developing seeds of Phaseolus vulgaris L. and Vicia faba L. by monitoring uptake of [¹⁴C]sugars into excised seed-coat halves and two different protoplast populations derived from seed coats. Sugar influxes by the two populations of protoplasts were similar for each sugar species [sucrose > (fructose ≈ glucose)] and hexoses competed with sucrose. Concentration-dependent influxes of all three sugars by excised seed coats could be described by a simple directly proportional relationship between concentration ([S]) and uptake rate (v) in the physiological range of sugar concentrations (v ≈ A.[S]). Alternatively, with the exception of fructose influx by Vicia, all could be fitted to a Michaelis-Menten relationship, as could sucrose uptake by Vicia protoplasts. Apparent K{subscript m} values were high (≈ 100–500 mM) compared with those reported for other systems. Sucrose transport was distinct from glucose and fructose transport in both species. Sugar influx was decreased by p-chloromercuribenzenesulfonic acid, carbonylcyanide m-chlorophenylhydrazone and erythrosin B. These responses are consistent with sugar/H⁺ symport acting to retrieve photoassimilates leaked to the apoplasm during post-sieve element transport within seed coats.
- Subject
- Phaseolus vulgaris L.; protoplasts; retrieval; seed coat; Sugar/H⁺ symport; Vicia faba L.
- Identifier
- uon:1676
- Identifier
- http://hdl.handle.net/1959.13/27443
- Identifier
- ISSN:0032-0781
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