Abstract
The uptake of sucrose into isolated discs cut from sink (growing) and source (sprouting) potato (Solanum tuberosum L.) tuber tissue was studied. The uptake of sucrose into sink-tuber discs demonstrated biphasic kinetics. The large saturable component was inhibited by incubation of the discs with p-chloromercuribenzene sulfonic acid (PCMBS) whilst both the saturable and linear components were inhibited by carbonyl cyanide m-chlorophenylhydrazone (CCCP). By contrast, in source-tuber discs, the linear component represented the majority of sucrose taken up, the saturable component playing only a minor role. In source discs, only the saturable component of uptake was inhibited by either PCMBS or CCCP. A large proportion (up to 25%) of sucrose taken up into sink-tuber discs was converted to starch but as the tubers aged the proportion of sucrose converted to starch decreased to the level found in source-tuber discs (approx. 3%). By contrast with sink-tuber discs (see Oparka and Wright, 1988b, Planta 175, 520–526) sucrose uptake into source discs was insensitive to turgor and demonstrated an uptake pattern similar to that of CCCP-treated sink tissue. It is proposed that exogenous sucrose is taken into the storage parenchyma of sink-tuber discs by both a carrier-mediated and a diffusional process. By contrast, uptake into the storage parenchyma of source-tuber discs appears to be essentially diffusional. The turgor sensitivity of sucrose uptake into sink-tissue discs may be mediated via the plasmalemma H+-ATPase. As the tuber ages the sucrose-uptake activity decreases and the capacity of the storage parenchyma to synthesise starch is lost. The data are discussed in relation to the in-vivo mechanisms of sucrose transport in storage tissues.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Ahmed, CH.M.S., Sagar, G.R. (1981) Patterns of distribution of assimilates in tubers of Solanum tuberosum L. with time. Potato Res. 24, 187–190
Browning, A.H., Hall, J., Baker, D.A. (1980) Cytochemical localization of ATPase activity in phloem tissues of Ricinus communis L. Protoplasma 104, 55–65
Daie, J. (1987a) Sucrose uptake in isolated phloem of celery is a single saturable transport system. Planta 171, 474–482
Daie, J. (1987b) Interaction of cell turgor and hormones on sucrose uptake in isolated phloem of celery. Plant Physiol. 84, 1033–1037
Davies, H.V., Ross, H.A. (1984) The pattern of starch and protein degradation in tubers. Potato Res. 27, 373–381
Delrot, S. (1987) Phloem loading: apoplastic or symplastic? Plant Physiol. Biochem. 25, 667–676
Fellows, R.J., Geiger, D.R. (1974) Structural and physiological changes in sugar beet leaves during sink to source conversion. Plant Physiol. 54, 877–885
Giaquinta, R. (1983) Phloem loading of sucrose. Annu. Rev. Plant Physiol. 34, 247–387
Gifford, R.M., Bremner, P.M. (1981) Accumulation and conversion of sugars by developing wheat grains. I. Liquid culture of kernels over several days. Aust. J. Plant Physiol. 8, 619–629
Ho, L.C. (1986) Metabolism and compartmentation of translocates in sink organs. In: Phloem transport, pp. 317–324, Cronshaw, J., Lucas, W.J., Giaquinta, R.T., eds. Alan R. Liss, Inc., New York
Ho, L.C., Gifford, R.M. (1984) Accumulation and conversion of sugars by developing wheat grains. V. The endosperm apoplast and apoplastic transport. J. Exp. Bot. 35, 58–73
Lin, W., Schmitt, M.R., Hitz, W.D., Giaquinta, R.T. (1984) Sugar transport into protoplasts isolated from developing soybean cotyledons. I. Protoplast isolation and general characteristics of sugar transport. Plant Physiol. 75, 936–940
Mares, C.J., Sowokinos, J.R., Hawker, J.S. (1985) Carbohydrate metabolism in developing potato tubers. In: Potato physiology, pp 279–327, Li, P.H., ed. Academic Press, New York
Maynard, J.W., Lucas, W.J. (1982) Sucrose and glucose uptake into Beta vulgaris tissue. A case for general (apoplastic) retrieval systems. Plant Physiol. 70, 436–1443
M'Batchi, B., El Ayadi, R., Delrot, S., Bonnemain, J.L. (1986) Direct versus indirect effects of p-chloromercuribenzenenesulphonic acid on sucrose uptake by plant tissues: The electrophysiological evidence. Physiol. Plant 68, 391–395
Oparka, K.J. (1985) Changes in partitioning of current assimilate during tuber bulking in potato (Solanum tuberosum L.) cv. Maris Piper. Ann. Bot. 55, 705–713
Oparka, K.J. (1986) Phloem unloading in the potato tuber. Pathways and sites of ATPase. Protoplasma 131, 201–210
Oparka, K.J., Prior, D.A.M. (1987) 14C sucrose efflux from the perimedulla of growing potato tubers. Plant Cell Environ. 10, 667–675
Oparka, K.J., Wright, K.M. (1988a) Osmotic regulation of starch synthesis in potato tubers? Planta 174, 123–126
Oparka, K.J., Wright, K.M. (1988b) Influence of cell turgor on sucrose partitioning in potato tuber storage tissues. Planta 175, 520–526
Ross, H.A., Davies, H.V. (1985) A microscopic examination of starch depletion in tubers of cv. Maris Piper during sprouting. Potato Res. 28, 113–118
Saftner, R.A., Daie, J., Wyse, R.E. (1983) Sucrose uptake and compartmentation in sugar beet taproot. Plant Physiol. 72, 1–6
Schmalstig, J.G., Geiger, D.R. (1985) Phloem unloading in developing leaves of sugar beet. I. Evidence for pathway through the symplast. Plant Physiol. 79, 237–241
Schmitt, M.R., Hitz, W.D., Lin, W., Giaquinta, R.T. (1984) Sugar transport into protoplasts isolated from developing soybean cotyledons. II. Sucrose transport kinetics, selectivity, and modelling studies. Plant Physiol. 75, 941–946
Stanzel, M., Sjolund, R.D., Komor, E. (1988) Transport of glucose, fructose and sucrose by Streptanthus tortuosus suspension cells. I. Uptake at low sugar concentration. Planta 174, 201–209
Thorne, J.H. (1982) Characterisation of the active sucrose transport system of immature soybean embryos. Plant Physiol. 70, 953–958
Thorne, J.H. (1985) Phloem unloading of C and N assimilates in developing seeds. Annu. Rev. Plant Physiol. 36, 317–341
Turgeon, R. (1984) Termination of nutrient import and development of vein loading capacity in albino tobacco leaves. Plant Physiol. 76, 45–48
Van Bel, A.J.E. (1987) The apoplastic concept of phloem loading has no universal validity. Plant Physiol. Biochem. 25, 677–686
Wyse, R.E., Zamski, E., Tomos, A.D. (1986) Turgor regulation of sucrose transport in sugar beet taproot tissue. Plant Physiol. 81, 478–481
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wright, K.M., Oparka, K.J. Sucrose uptake and partitioning in discs derived from source versus sink potato tubers. Planta 177, 237–244 (1989). https://doi.org/10.1007/BF00392812
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00392812