Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-23T11:03:15.112Z Has data issue: false hasContentIssue false
  • English
  • Français

Transport of nutrients into developing seeds: a review of physiological mechanisms

Published online by Cambridge University Press:  19 September 2008

P. Wolswinkel
P. Wolswinkel
Affiliation:
Transport Physiology Research Group, Department of Plant Ecology and Evolutionary Biology, University of Utrecht, PO Box 800 84, 3508 TB Utrecht, Netherlands
Get access Rights & Permissions [Opens in a new window]

Abstract

After synthesis in the vegetative parts of the plant, assimilates are translocated to fruits through xylem and phloem. Research on factors controlling nutrient transport into developing seeds via the phloem has been stimulated by the development of the empty seed coat technique.

There is a consensus that as assimilates are transported from maternal tissues to filial tissues they are delivered to the extracellular space (the apoplast) separating the two generations, prior to uptake from the apoplast into the tissues of the embryo or endosperm. The empty seed coat technique has been used for the study of several aspects of nutrient transport into seeds, e.g. metabolic control and turgorsensitive transport. The osmotic environment of seed tissues has a strong effect on assimilate transport into empty seeds. Several lines of evidence suggest that one of the main ‘secrets’ of the high sink strength of developing seeds, at least in many taxonomic groups of dicotyledons, is that the sink end of the phloem pathway is ‘bathed’ in an apoplast solution with a high concentration of osmotically active solutes. Data on maize do not fit this pattern. A turgor homeostat mechanism may help to maintain high solute concentrations in the seed apoplast. The apoplast environment of seed tissues may also stimulate synthesis of storage proteins and be involved in the prevention of precocious germination. In addition to the osmotic environment, other factors influencing sink strength are discussed. Some aspects of solute transformation during transport through seed tissues are described.

Keywords

assimilate transportcerealslegumesphloem transportseed developmentsink strengthturgor-sensitive transport
Type
Review Article
Information
Seed Science Research , Volume 2 , Issue 2 , June 1992 , pp. 59 - 73
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baker, D.A. and Milburn, J.A. (Eds) (1989) Transport of photoassimilates. Harlow, Longman Scientific & Technical.Google Scholar
Barlow, E.W.R., Lee, J.W., Munns, R. and Smart, M.G. (1980) Water relations of the developing wheat grain. Australian Journal of Plant Physiology 7, 519–525.Google Scholar
Bennett, A.B., Sweger, B.L. and Spanswick, R.M. (1984) Sink to source translocation in soybean. Plant Physiology 74, 434–436.CrossRefGoogle ScholarPubMed
Bewley, J.D. and Black, M. (1978) Physiology and biochemistry of seeds in relation to germination. I. Development, germination, and growth. Berlin, Springer-Verlag.Google Scholar
Black, M. (1989) Seed research – past, present and future. pp. 1–6 in Taylorson, R.B. (Ed.) Recent advances in the development and germination of seeds. New York, Plenum Press.Google Scholar
Carman, J.G. (1988) Improved somatic embryogenesis in wheat by partial stimulation of the in-ovulo oxygen, growth-regulator and desiccation environments. Planta 175, 417–424.CrossRefGoogle Scholar
Delrot, S. (1989) Loading of photoassimilates. pp. 167–205 in Baker, D.A. and Milburn, J.A. (Eds) Transport of photoassimulates. Harlow, Longman Scientific & Technical.Google Scholar
Doehlert, D.C. and Felker, F.C. (1987) Characterization and distribution of invertase activity in developing maize (Zea mays) kernels. Physiologia Plantarum 70, 51–57.CrossRefGoogle Scholar
Dure, L.S. III (1975) Seed formation. Annual Review of Plant Physiology 26, 259–278.CrossRefGoogle Scholar
Ellis, E.C. and Spanswick, R.M. (1987) Sugar efflux from attached seed coats of Glycine max (L.) Merr. Journal of Experiemtal Botany 38, 1470–1483.CrossRefGoogle Scholar
Eschrich, W. (1980) Free space invertase, its possible role in phloem unloading. Berichte der Deutschen Botanischen Gesellschaft 93, 363–378.CrossRefGoogle Scholar
Evenari, M. (1984) Seed physiology: from ovule to maturing seed. The Botanical Review 50, 143–70.CrossRefGoogle Scholar
Felker, F.C. and Shannon, J.C. (1980) Movement of 14Clabeled assimilates into kernels of Zea mays L. III. An anatomical examination and microautoradiographic study of assimilate transfer. Plant Physiology 65, 864–870.CrossRefGoogle ScholarPubMed
Findlay, N., Oliver, K.J., Nii, N. and Coombe, R. (1987) Solute accumulation by grape pericarp cells. IV. Perfusion of pericarp apoplast via the pedicel and evidence for xylem malfunction in ripening berries. Journal of Experimental Botany 38, 668–679.CrossRefGoogle Scholar
Finkelstein, R.R. and Crouch, M.L. (1986) Rapeseed embryo development in culture on high osmoticum is similar to that in seeds. Plant Physiology 81, 907–912.CrossRefGoogle ScholarPubMed
Fischer, W., Bergfeld, R., Plachy, C., Schäfer, R. and Schopfer, P. (1988) Accumulation of storage materials, precocious germination and development of desiccation tolerance during seed maturation in mustard (Sinapis alba L.) Botanica Acta 101, 344–354.Google Scholar
Fisher, D.B. and Gifford, R.M. (1986) Accumulation and conversion of sugars by developing wheat grains. VI. Gradients along the transport pathway from the peduncle to the endosperm cavity during grain filling. Plant Physiology 82, 1024–1030.CrossRefGoogle Scholar
Frazier, J.C. and Appalanaidu, B. (1965) The wheat grain during development with reference to nature, location and role of its translocatory tissues. American Journal of Botany 52, 193–198.CrossRefGoogle Scholar
Frick, H. and Pizzolato, T.D. (1987) Adaptive value of the xylem discontinuity in partitioning of photassimilate to the grain. Bulletin of the Torrey Botanical Club 114, 252–259.CrossRefGoogle Scholar
Galau, G.A., Jakobsen, K.S. and Hughes, D.W. (1991) The controls of late dicot embryogenesis and early germination. Physiologia Plantarum 81, 280–288.CrossRefGoogle Scholar
Gamalei, Y. (1989) Structure and function of leaf minor veins in trees and herbs. A taxonomic review. Trees 3, 96–110.CrossRefGoogle Scholar
Geiger, D.R. (1975) Phloem loading. pp. 395–431 in Zimmermann, M.H. and Milburn, J.A. (Eds) Encyclopedia of Plant Physiology, New Series, Vol. 1. Berlin, Springer-Verlag.Google Scholar
Giaquinta, R.T. (1983) Phloem loading of sucrose. Annual Review of Plant Physiology 34, 347–387.CrossRefGoogle Scholar
Gifford, R.M. and Thorne, J.H. (1985) Sucrose concentration at the apoplastic interface between seed coat and cotyledons of developing soybean seeds. Plant Physiology 77, 863–868.CrossRefGoogle ScholarPubMed
Gougler Schmalstig, J. and Hitz, W.D. (1987) Transport and metabolism of a sucrose analog (1'-fluorosucrose) into Zea mays L. endosperm without invertase hydrolysis. Plant Physiology 85, 902–905.CrossRefGoogle Scholar
Groot, S.P.C., Van Yperen, I.I. and Karssen, C.M. (1991) Strongly reduced levels of endogenous abscisic acid in developing seeds of tomato mutant sitiens do not influence in vivo accumulation of dry matter and storage proteins. Physiologia Plantarum 81, 73–78.CrossRefGoogle Scholar
Grusak, M.A. and Minchin, P.E.H. (1988) Seed coat unloading in Pisum sativum: osmotic effects in attached versus excised empty ovules. Journal of Experimental Botany 39, 543–559.CrossRefGoogle Scholar
Guldan, S.J. and Brun, W.A. (1987) Relationship of tissue water relations to asparagine uptake in developing soybean seeds. Crop Science 27, 720–725.CrossRefGoogle Scholar
Hamilton, D.A. and Davies, P.J. (1988) Mechanism of export of organic material from the developing fruits of pea. Plant Physiology 85, 956–959.CrossRefGoogle Scholar
Hardham, A.R. (1976) Structural aspects of the pathways of nutrient flow to developing embryo and cotyledons of Pisum sativum L. Australian Journal of Botany 24, 711–721.CrossRefGoogle Scholar
Ho, L.C. (1988) Metabolism and compartmentation of imported sugars in sink organs in relation to sink strength. Annual Review of Plant Physiology and Plant Molecular Biology 39, 355–378.CrossRefGoogle Scholar
Ho, L.C. and Gifford, R.M. (1984) Accumulation and conversion of sugars by developing wheat grains. V. The endosperm apoplast and apoplastic transport. Journal of Experimental Botany 35, 58–73.Google Scholar
Ho, L.C., Grange, R.I. and Shaw, A.F. (1989) Source/sink regulation. pp. 306–343 in Baker, D.A. and Milburn, J.A. (Eds). Transport of photoassimilates. Harlow, Longman Scientific & Technical.Google Scholar
Hocking, P.J. and Pate, J.S (1977) Mobilization of minerals to developing seeds of legumes. Annals of Botany 41, 1259–1278.CrossRefGoogle Scholar
Jenner, C.F. (1976) Physiological investigations on restrictions to transport of sucrose in ears of wheat. Australian Journal of Plant Physiology 3, 337–347.Google Scholar
Jenner, C.F. (1980) The conversion of sucrose to starch in developing fruits. Berichte der Deutschen Botanischen Gesellschaft 93, 289–298.CrossRefGoogle Scholar
Jenner, C.F., Ugalde, T.D. and Aspinall, D. (1991) The physiology of starch and protein deposition in the endosperm of wheat. Australian Journal of Plant Physiology 18, 211–226.Google Scholar
Kallarackal, J. and Milburn, J.A. (1984) Specific mass transfer and sink-controlled phloem translocation in castor bean. Australian Journal of Plant Physiology 11, 483–490.Google Scholar
Lanfermeijer, F.C., Koerselman-Kooij, J.W. and Borstlap, A.C. (1990a) Effects of medium osmolarity on the release of amino acids from isolated cotyledons of developing pea seeds. Evidence for vacuolar aminoacid release at increased turgor. Planta 181, 568–575.CrossRefGoogle ScholarPubMed
Lanfermeijer, F.C., Koerselman-Kooij, J.W. and Borstlap, A.C. (1990b) Changing kinetics of L-valine uptake by immature pea cotyledons during development. An unsaturable pathway is supplemented by a saturable system. Planta 181, 576–582.CrossRefGoogle ScholarPubMed
Lanfermeijer, F.C., Koerselman-Kooij, J.W. and Borstlap, A.C. (1991) Osmosensitivity of sucrose uptake by immature pea cotyledons disappears during development. Plant Physiology 95, 832–838.CrossRefGoogle ScholarPubMed
Lang, A. and Düring, H. (1991) Partitioning control by water potential gradient: evidence for compartmentation breakdown in grape berries. Journal of Experimental Botany 42, 1117–1122.CrossRefGoogle Scholar
Lee, D.R. (1989) Vasculature of the abscission zone of tomato fruit: implications for transport. Canadian Journal of Botany 67, 1898–1902.CrossRefGoogle Scholar
Lichtner, F.T. and Spanswick, R.M. (1981) Sucrose uptake by developing soybean cotyledons. Plant Physiology 68, 693–698.CrossRefGoogle ScholarPubMed
Lopez, R., Dathe, W. and Sembdner, G. (1989) Abscisic acid in different parts of the developing soybean fruit. Biochemie und Physiologie der Pflanzen 184, 267–276.CrossRefGoogle Scholar
Lott, J.N.A. (1984) Accumulation of seed reserves of phosphorus and other minerals. pp. 139–166 in Murray, D.R. (Ed.). Seed physiology, Vol. 1, Development. Sydney, Academic Press.Google Scholar
Maness, N.O. and McBee, G.G. (1986) Role of placental sac in endosperm carbohydrate import in Sorghum caryopses. Crop Science 26, 1201–1207.CrossRefGoogle Scholar
Marinos, N.G. (1970) Embryogenesis of the pea (Pisum sativum). I. The cytological environment of the developing embryo. Protoplasma 70, 261–279.CrossRefGoogle Scholar
Milburn, J.A. (1975) Pressure flow. pp. 328–353 in Zimmermann, M.H. and Milburn, J.A. (Eds) Encyclopedia of Plant Physiology, New Series, Vol. 1. Berlin, Springer-Verlag.Google Scholar
Milburn, J.A. and Baker, D.A. (1989) Physico–chemical aspects of phloem sap. pp. 345–359 in Baker, D.A. and Milburn, J.A. (Eds) Transport of photoassimilates. Harlow, Longman Scientific & Technical.Google Scholar
Minchin, P.E.H. and Thorpe, M.R. (1989) Carbon partitioning to whole versus surgically modified ovules of pea: an application of the in vivo measurement of carbon flows over many hours using the short-lived isotope carbon-11. Journal of Experimental Botany 40, 781–787.CrossRefGoogle Scholar
Mix, G.P. and Marschner, H. (1976) Redistribution of calcium in bean fruits during seed development. Zeitschrift für Pflanzenphysiologie 80, 354–366.CrossRefGoogle Scholar
Münch, E. (1930) Die Stoffbewegungen in der Pflanze. Jena Fischer.Google Scholar
Murray, D.R. (1980) Functional significance of acid phosphatase distribution during embryo development in Pisum sativum L. Annals of Botany 45, 273–281.CrossRefGoogle Scholar
Murray, D.R. (1983) Changes in free amino acid and amide composition during fruit and seed development of garden pea, Pisum sativum L. New Phytologist 93, 33–41.CrossRefGoogle Scholar
Murray, D.R. (Ed.) (1984) Seed physiology, Vol. 1, Development. Sydney, Academic Press.Google Scholar
Murray, D.R. (1987) Nutritive role of seed coats in developing legume seeds. American Journal of Botany 74, 1122–1137.CrossRefGoogle Scholar
Murray, D.R. (1988) Nutrition of the angiosperm embryo. Taunton, Research Studies Press.Google Scholar
Murray, D.R. and Cordova-Edwards, M. (1984) Amino acid and amide metabolism in the hulls and seeds of developing fruits of garden pea, Pisum sativum. II. Asparagine. New Phytologist 97, 253–260.CrossRefGoogle Scholar
Obendorf, R.L. and Wettlaufer, S.H. (1984) Precocious germination during in vitro growth of soybean seeds. Plant Physiology 76, 1024–1028.CrossRefGoogle ScholarPubMed
Offler, C.E. and Patrick, J.W. (1984) Cellular structures, plasma membrane surface areas and plasmodesmatal frequencies of seed coats of Phaseolus vulgaris L. in relation to photosynthate transfer. Australian Journal of Plant Physiology 11, 79–99.Google Scholar
Offler, C.E., Nerlich, S.M. and Patrick, J.W. (1989) Pathway of photosynthate transfer in the developing seed of Vicia faba L. Transfer in relation to seed anatomy. Journal of Experimental Botany 40, 769–780.CrossRefGoogle Scholar
Oparka, K.J. (1990) What is phloem unloading? Plant Physiology 94, 393–396.Google Scholar
Oparka, K.J. and Gates, P. (1981a) Transport of assimilates in the developing caryopsis of rice (Oryza sativa L.). Ultrastructure of the pericarp vascular bundle and its connection with the aleurone layer. Planta 151, 561–573.CrossRefGoogle ScholarPubMed
Oparka, K.J. and Gates, P. (1981b) Transport of assimilates in the developing caryopsis of rice (Oryza sativa L.). The pathway of water and assimilated carbon. Planta 152. 388–396.CrossRefGoogle ScholarPubMed
Ouattar, S., Jones, R.J., Crookston, R.K. and Kajeiou, M. (1987) Effect of drought on water relations of developing maize kernels. Crop Science 27, 730–735.CrossRefGoogle Scholar
Pate, J.S. (1975) Exchange of solutes between phloem and xylem and circulation in the whole plant. pp. 451–473 in Zimmermann, M.H. and Milburn, J.A. (Eds) Encyclopedia of Plant Physiology, New Series, Vol. 1. Berlin, Springer-Verlag.Google Scholar
Pate, J.S. (1989) Origin, destination and fate of phloem solutes in relation to organ and whole plant functioning. pp. 138–166 in Baker, D.A. and Milburn, J.A. (Eds) Transport of photoassimilates. Harlow, Longman Scientific & Technical.Google Scholar
Patrick, J.W. (1981) An in vitro assay of sucrose uptake by developing bean cotyledons. Australian Journal of Plant Physiology 8, 221–235.Google Scholar
Patrick, J.W. (1983) Photosynthate unloading from seed coats of Phaseolus vulgaris L. General characteristics and facilitated transfer. Zeitschrift für Planzenphysiologie 111, 9–18.CrossRefGoogle Scholar
Patrick, J.W. (1984) Photosynthate unloading from seed coats of Phaseolus vulgaris L. Control by tissue water relations. Journal of Plant Physiology 115, 297–310.CrossRefGoogle ScholarPubMed
Patrick, J.W. (1990) Sieve element unloading: cellular pathway, mechanism and control. Physiologia Plantarum 78, 298–308.CrossRefGoogle Scholar
Patrick, J.W. and McDonald, R. (1980) Pathway of carbon transport within developing ovules of Phaseolus vulgaris L. Australian Journal of Plant Physiology 7, 671–684.Google Scholar
Patrick, J.W., Jacobs, E., Offler, C.E. and Cram, W.J. (1986) Photosynthate unloading from seed coats of Phaseolus vulgaris L. Nature and cellular location of turgor-sensitive unloading. Journal of Experimental Botany 37, 1006–1019.CrossRefGoogle Scholar
Patrick, J.W., Offler, C.E., Wang, H.L., Wang, X.-D., Jin, S.-P., Zhang, W.-C., Ugalde, T.D., Jenner, C.F., Wang, N., Fisher, D.B., Felker, F.C., Thomas, P.A. and Crawford, C.G. (1991) Assimilate transport in developing cereal grain. pp. 233–243 in Bonnemain, J.L., Delrot, S., Lucas, W.J. and Dainty, J. (Eds) Recent advances in phloem transport and assimilate compartmentation. Nantes, Ouest Editions (Presses Academiques).Google Scholar
Porter, G.A., Knievel, D.P. and Shannon, J.C. (1985) Sugar efflux from maize (Zea mays L.) pedicel tissue. Plant Physiology 77, 524–531.CrossRefGoogle ScholarPubMed
Porter, G.A., Knievel, D.P. and Shannon, J.C. (1987a) Assimilate unloading from maize (Zea mays L.) pedicel tissues. I. Evidence for regulation of unloading by cell turgor. Plant Physiology 83, 131–136.CrossRefGoogle ScholarPubMed
Porter, G.A., Knievel, D.P. and Shannon, J.C. (1987b) Assimilate unloading from maize (Zea mays L.) pedicel tissues. II. Effects of chemical agents on sugar, amino acid, and 14C-assimilate unloading. Plant Physiology, 85, 558–565.CrossRefGoogle Scholar
Rainbird, R.M., Thorne, J.H. and Hardy, W.F. (1984) Role of amides, amino acids, and ureides in the nutrition of developing soybean seeds. Plant Physiology 74, 329–334.CrossRefGoogle ScholarPubMed
Ripp, K.G., Viitanen, P.V., Hitz, W.D. and Franceschi, V.R. (1988) Identification of a membrane protein associated with sucrose transport into cells of developing soybean cotyledons. Plant Physiology 88, 1435–1445.CrossRefGoogle ScholarPubMed
Roberts, D.R. (1991) Abscisic acid and mannitol promote early development, maturation and storage protein accumulation in somatic embryos of interior spruce. Physiologia Plantarum 83, 247–254.CrossRefGoogle Scholar
Rochat, C. (1991) Role des organes maternels dans la regulation de la nutrition de L'embryon de pois (Pisum sativum L. cv Finale) au cours de son développement sur la plante-mère. Thése de Doctorat, Université Paris 6.Google Scholar
Rochat, C. and Boutin, J.-P. (1989) Carbohydrates and nitrogenous compounds in the hull and in the seed during the pod development of pea. Plant Physiology and Biochemistry 27, 881–887.Google Scholar
Rochat, C. and Boutin, J.-P. (1991) Metabolism of phloemborne amino acids in maternal tissues of fruit of nodulated or nitrate-fed pea plants (Pisum sativum L.). Journal of Experimental Botany 42, 207–214.CrossRefGoogle Scholar
Ryczkowski, M., Kowalska, A. and Reczynski, W. (1986) Element concentrations in the sap surrounding the developing embryo of Aesculus hybrida. Journal of Plant Physiology 122, 467–472.CrossRefGoogle Scholar
Saab, I.N. and Obendorf, R.L. (1989) Soybean seed water relations during in situ and in vitro growth and maturation. Plant Physiology 89, 610–616.CrossRefGoogle ScholarPubMed
Sakri, F.A.K. and Shannon, J.C. (1975) Movement of 14Clabelled sugars into kernels of wheat (Triticum aestivum L.). Plant Physiology 55, 881–889.CrossRefGoogle Scholar
Schussler, J.R., Brenner, M.L. and Brun, W.A. (1984) Abscisic acid and its relationship to seed filling in soybean. Plant Physiology 76, 301–306.CrossRefGoogle Scholar
Schussler, J.R., Brenner, M.L. and Brun, W.A. (1991) Relationship of endogenous abscisic acid to sucrose level and seed growth rate of soybeans. Plant Physiology 96, 1308–1313.CrossRefGoogle ScholarPubMed
Shannon, J.C. (1972) Movement of 14 C-labeled assimilates into kernels of Zea mays L. I. Pattern and rate of sugar movement. Plant Physiology 49, 198–202.CrossRefGoogle Scholar
Shannon, J.C., Porter, G.A. and Knievel, D.P. (1986) Phloem unloading and transfer of sugars into developing corn endosperm. pp. 265–277 in Cronshaw, J., Lucas, W.J. and Giaquinta, R.T. (Eds) Phloem transport. New York, Alan R. Liss.Google Scholar
Smith, J.G. (1973) Embryo development in Phaseolus vulgaris. II. Analysis of selected inorganic ions, ammonia, organic acids, and sugars in the endosperm liquid. Plant Physiology 51, 454–458.CrossRefGoogle ScholarPubMed
Smith, J.A.C. and Milburn, J.A. (1980) Phloem turgor and the regulation of sucrose loading in Ricinus communis L. Planta 148, 42–48.CrossRefGoogle ScholarPubMed
Thorne, J.H. (1980) Kinetics of 14C-photosynthate uptake by developing soybean fruit. Plant Physiology 65, 975–979.CrossRefGoogle Scholar
Thorne, J.H. (1981) Morphology and ultrastructure of maternal seed tissues of soybean in relation to the import of photosynthate. Plant Physiology 67, 1016–1025.CrossRefGoogle Scholar
Thorne, J.H. (1982a) Temperature and oxygen effects on 14C-photosynthate unloading and accumulation in developing soybean seeds. Plant Physiology 69, 48–53.CrossRefGoogle Scholar
Thorne, J.H. (1982b) Characterization of the active sucrose transport system of immature soybean embryos. Plant Physiology 70, 953–958.CrossRefGoogle ScholarPubMed
Thorne, J.H. (1985) Phloem unloading of C and N assimilates in developing seeds. Annual Review of Plant Physiology 36, 317–343.CrossRefGoogle Scholar
Thorne, J.H. and Rainbird, R.M. (1983) An in vivo technique for the study of phloem unloading in seed coats of developing soybean seeds. Plant Physiology 72, 268–271.CrossRefGoogle Scholar
Van Oene, M.A., Terlou, M. and Wolswinkel, P. (in press) Effect of reduction of sink strength in developing seeds on vein loading patterns of photoassimilate in source leaves of Pisum sativum L. Journal of Experimental Botany.Google Scholar
Walbot, V. (1978) Control mechanisms for plant embryogeny. pp. 113–166 in Clutter, M.E. (Ed.) Dormancy and developmental arrest. Experimental analysis in plants and animals. New York, Academic Press.Google Scholar
Wang, T.L., Cook, S.K., Francis, R.J., Ambrose, M.J. and Hedley, C.L. (1987) An analysis of seed development in Pisum sativum. VI. Abscisic acid accumulation. Journal of Experimental Botany 38, 1921–1932.CrossRefGoogle Scholar
Wang, T.L. and Hedley, C.L. (1991) Seed development in peas: knowing your three ‘r's’ (or four, or five). Seed Science Research 1, 3–14.CrossRefGoogle Scholar
Wareing, P.F. and Patrick, J.W. (1975) Source-sink relations and the partitioning of assimilates in the plant pp. 481–499 in Cooper, J.P. (Ed.) Photosynthesis and productivity in different environments. Cambridge, Cambridge University Press.Google Scholar
Wellbaum, G.E. and Meinzer, F.C. (1990) Compartmentation of solutes and water in developing sugarcane stalk tissue. Plant Physiology 93, 1147–1153.CrossRefGoogle Scholar
Westgate, M.E. and Thomson Grant, D.L. (1989a) Water deficits and reproduction in maize. Response of the reproductive tissue to water deficits at anthesis and mid-grain fill. Plant Physiology 91, 862–867.CrossRefGoogle ScholarPubMed
Westgate, M.E. and Thomson Grant, D.L. (1989b) Effect of water deficits on seed development in soybean. I. Tissue water status. Plant Physiology 91, 975–979.CrossRefGoogle ScholarPubMed
Westgate, M.E., Schussler, J.R., Reicosky, D.C. and Brenner, M.L. (1989) Effect of water deficits on seed development in soybean. II. Conservation of seed growth rate. Plant Physiology 91, 980–985.CrossRefGoogle ScholarPubMed
Wolswinkel, P. (1984) Phloem unloading and ‘sink strength’: the parallel between the site of attachment of Cuscuta and developing legume seeds. Plant Growth Regulation 2, 309–317.CrossRefGoogle Scholar
Wolswinkel, P. (1985a) Effect of inhibitors on solute efflux from seed-coat halves and cotyledons of Pisum sativum L., after uptake from a bathing medium. The difference between sucrose and amino acids. Journal of Plant Physiology 120, 419–429.CrossRefGoogle Scholar
Wolswinkel, P. (1985b) Phloem unloading and turgorsensitive transport: factors involved in sink control of assimilate partitioning. Physiologia Plantarum 65, 331–339.CrossRefGoogle Scholar
Wolswinkel, P. (1987a) Assimilate transport in developing seeds of sunflower (Helianthus annuus L.). Journal of Plant Physiology 127, 1–10.CrossRefGoogle Scholar
Wolswinkel, P. (1987b) The role of maternal tissues in the sink control of assimilate transport into developing seeds. Plant Physiology and Biochemistry 25, 557–566.Google Scholar
Wolswinkel, P. (1990) Recent progress in research on the role of turgor-sensitive transport in seed development. Plant Physiology and Biochemistry 28, 399–410.Google Scholar
Wolswinkel, P. (1991) Sucrose transport into, and unloading from, the seed coat of ‘empty’ seeds over time-spans greater than 150 minutes. Plant Physiology 96 (Supplement), 151.Google Scholar
Wolswinke, P. and Ammerlaan, A. (1983) Phloem unloading in developing seeds of Vicia faba L. The effect of several inhibitors on the release of sucrose and amino acids by the seed coat. Planta 158, 205–215.Google Scholar
Wolswinkel, P. and Ammerlaan, A. (1984) Turgor-sensitive sucrose and amino acid transport into developing seeds of Pisum sativum. Effect of a high sucrose or mannitol concentration in experiments with empty ovules. Physiologia Plantarum 61, 172–182.CrossRefGoogle Scholar
Wolswinkel, P. and Ammerlaan, A. (1986) Turgor-sensitive transport in developing seeds of legumes: the role of the stage of development and the use of excised vs. attached seed coats. Plant, Cell and Environment 9, 133–140.CrossRefGoogle Scholar
Wolswinkel, P. and Ammerlaan, A. (1988) Effect of the osmotic environment of the seed coat on sucrose and amino acid transport into developing seeds of Lunaria annua, Acer pseudoplatanus and Glycine max. Physiologia Plantarum 74, 262–269.CrossRefGoogle Scholar
Wolswinkel, P. and Ammerlaan, A. (1989) Effect of the osmotic environment on assimilate transport in isolated developing embryos of maize (Zea mays). Annals of Botany 63, 283–287.CrossRefGoogle Scholar
Wolswinkel, P. and De Ruiter, H. (1985) Amino acid release from the seed coat of developing seeds of Vicia faba and Pisum sativum. Annals of Botany 63, 705–708.CrossRefGoogle Scholar
Wolswinkel, P. and Koerselman-Kooij, J.W. (in press) Effect of a pretreatment of seed coats with a low-osmolality solution on subsequent [14C] sucrose transport into attached empty ovules of pea. Plant, Cell and Environment 15.Google Scholar
Wolswinkel, P., Kraus, E. and Ammerlaan, A. (1986) Effect of the osmotic environment on the balance between uptake and release of sucrose and amino acids by the seed coat and cotyledons of developing seeds of Pisum sativum. Journal of Experimental Botany 37, 1462–1471.CrossRefGoogle Scholar
Wolswinkel, P., Ammerlaan, A. and Koerselman-Kooij, J.W. (in press) Effect of the osmotic environment on K+ and Mg2+ release from the seed coat and cotyledons of developing seeds of Vicia faba and Pisum sativum. Evidence for a stimulation of efflux from the vacuole at high cell turgor. Journal of Experimental Botany.Google Scholar
Wyse, R.E., Zamski, E. and Tomos, A.D. (1986) Turgor regulation of sucrose transport in sugar beet taproot tissue. Plant Physiology 81, 478–481.CrossRefGoogle ScholarPubMed
Yeung, E.C. and Brown, D.C.W. (1982) The osmotic environment of developing embryos of Phaseolus vulgaris. Zeitschrift für Pflanzenphysiologie 106, 149–156.CrossRefGoogle Scholar
Ziegler, H. (1975) Nature of transported substances. pp. 59–100 in Zimmermann, M.H. and Milburn, J.A. (Eds) Encyclopedia of Plant Physiology, New Series, Vol. 1. Berlin, Springer-Verlag.Google Scholar
Zimmermann, M.H. and Milburn, J.A. (Eds) (1975) Transport in plants. I. Phloem transport. Encyclopedia of Plant Physiology, New series, Vol. 1. Berlin, Springer-Verlag.Google Scholar
Zimmermann, M.H. and Ziegler, H. (1975) List of sugars and sugar alcohols in sieve-tube exudates. pp. 480–503 in Zimmermann, M.H. and Milburn, J.A. (Eds) Encyclopedia of Plant Physiology, New Series, Vol. 1. Berlin, Springer-Verlag.Google Scholar