Textbook

Pathways of Translocation

Andriunas, F. A., Zhang, H.-M., Xia, X., Patrick, J. W., and Offler, C. E. (2013) Intersection of transfer cells with phloem biology—Broad evolutionary trends, function, and induction. Front. Plant Sci. 4: 221. [DOI: 10.3389/fpls.2013.00221]

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Brentwood, B., and Cronshaw, J. (1978) Cytochemical localization of adenosine triphosphatase in the phloem of Pisum sativum and its relation to the function of transfer cells. Planta 140: 111–120.

Clark, A. M., Jacobsen, K. R., Bostwick, D. E., Dannenhoffer, J. M., Skaggs, M. I., and Thompson, G. A. (1997) Molecular characterization of a phloem-specific gene encoding the filament protein, phloem protein 1 (PP1), from Cucurbita maxima. Plant J. 12: 49–61.

Ernst, A. M., Jekat, S. B., Zielonka, S., Muller, B., Neumann, U., Ruping, B., Twyman, R. M., Krzyzanek, V., Prufer, D., and Noll, G. A. (2012) Sieve element occlusion (SEO) genes encode structural phloem proteins involved in wound sealing of the phloem. Proc. Natl. Acad. Sci. USA 119: E1980–E1989.

Evert, R. F. (1982) Sieve-tube structure in relation to function. Bioscience 32: 789–795.

Froelich, D. R., Mullendore, D. L., Jensen, K. H., Ross-Elliott, T. J., Anstead, J. A., Thompson, G. A., Pelissier, H. C., and Knoblauch, M. (2011) Phloem ultrastructure and pressure flow: Sieve-Element-Occlusion-Related agglomerations do not affect translocation. Plant Cell 23: 4428–4445.

Hao, P., Liu, C., Wang, Y., Chen, R., Tang, M., Du, B., Zhu, L., and He, G. (2008) Herbivore-induced callose deposition on the sieve plates of rice: An important mechansim for host resistance. Plant Physiol. 146: 1810–1820.

Jekat, S. B., Ernst, A. M., von Bohl, A., Zielonka, S., Twyman, R. M., Noll, G. A., and Prufer, D. (2013) P-proteins in Arabidopsis are heteromeric structures involved in rapid sieve tube sealing. Front. Plant Sci. 4: 225. [DOI: 10.3389/fpls.2013.00225]

Mullendore, D. L., Windt, C. W., Van As, H., and Knoblauch, M. (2010) Sieve tube geometry in relation to phloem flow. Plant Cell 22: 579–593.

Paiva, E. A. S., and Machado, S. R. (2008) Can sieve-element plastids in Panicum maximum (Poaceae) leaves act in the blockage of injured sieve-tube elements? Flora 203: 327–331.

Schulz, A. (1990) Conifers. In Sieve Elements: Comparative Structure, Induction and Development, H.-D. Behnke and R. D. Sjolund, eds., Springer-Verlag, Berlin.

Truernit, E., Bauby, H., Dubreucq, B., Grandjean, O., Runions, J., Barthelemy, J., and Palauqui, J.-C. (2008) High-resolution whole-mount imaging of three-dimensional tissue organization and gene expression enables the study of phloem development and structure in Arabidopsis. Plant Cell 20: 1494–1503.

Turgeon, R., Beebe, D. U., and Gowan, E. (1993) The intermediary cell: Minor-vein anatomy and raffinose oligosaccharide synthesis in the Scrophulariaceae. Planta 191: 446–456.

Warmbrodt, R. D. (1985) Studies on the root of Hordeum vulgare L.—Ultrastructure of the seminal root with special reference to the phloem. Am. J. Bot. 72: 414–432.

Patterns of Translocation: Source to Sink

Joy, K. W. (1964) Translocation in sugar beet. I. Assimilation of ¹⁴CO₂ and distribution of materials from leaves. J. Exp. Bot. 15: 485–494.

Materials Translocated in the Phloem

Doering-Saad, C., Newbury, H. J., Bale, J. S., and Pritchard, J. (2002) Use of aphid stylectomy and RT-PCR for the detection of transporter mRNAs in sieve elements. J. Exp. Bot. 53: 631–637.

Gaupels, F., Knauer, T., and van Bel, A. J. E. (2008) A combinatory approach for analysis of protein sets in barley sieve-tube samples using EDTA-facilitated exudation and aphid stylectomy. J. Plant Physiol. 165: 95–103.

Hall, S. M., and Baker, D. A. (1972) The chemical composition of Ricinus phloem exudate. Planta 106: 131–140.

Liu, D. D., Chao, W. M., and Turgeon, R. (2012) Transport of sucrose, not hexose, in the phloem. J. Exp. Bot. 63: 4315–4320.

Turgeon, R., and Wolf, S. (2009) Phloem transport: Cellular pathways and molecular trafficking. Annu. Rev. Plant Biol. 60: 207–221.

Walz, C., Giavalisco, P., Schad, M., Juenger, M., Klose, J., and Kehr, J. (2004) Proteomics of cucurbit phloem exudate reveals a network of defence proteins. Phytochemistry 65: 1795–1804.

Zhang, C., Yu, X., Ayre, B. G., and Turgeon, R. (2012) The origin and composition of cucurbit “phloem” exudate. Plant Physiol. 158: 1873–1882.

Zimmermann, M. R., Hafke, J. B., van Bel, A. J. E., and Furch, A. C. U. (2013) Interaction of xylem and phloem during exudation and wound occlusion in Cucurbita maxima. Plant Cell Environ. 36: 237–247.

Rates of Movement

Windt, C. W., Vergeldt, F. J., De Jager, P. A., and Van As, H. (2006) MRI of long-distance water transport: A comparison of the phloem and xylem flow characteristics and dynamics in poplar, castor bean, tomato and tobacco. Plant Cell Environ. 29: 1715–1729.

The Pressure-Flow Model, a Passive Mechanism for Phloem Transport

De Schepper, V., Vanhaecke, L., and Steppe, K. (2011) Localized stem chilling alters carbon processes in the adjacent stem and in source leaves. Tree Physiol. 31: 1194–1203.

Fisher, D. B. (1978) An evaluation of the Münch hypothesis for phloem transport in soybean. Planta 139: 25–28.

Froelich, D. R., Mullendore, D. L., Jensen, K. H., Ross-Elliott, T. J., Anstead, J. A., Thompson, G. A., Pelissier, H. C., and Knoblauch, M. (2011) Phloem ultrastructure and pressure flow: Sieve-Element-Occlusion-Related agglomerations do not affect translocation. Plant Cell 23: 4428–4445.

Geiger, D. R., and Sovonick, S. A. (1975) Effects of temperature, anoxia and other metabolic inhibitors on translocation. In Transport in Plants, 1: Phloem Transport (Encyclopedia of Plant Physiology, New Series, Vol. 1), M. H. Zimmerman and J. A. Milburn, eds., Springer, New York, pp. 256–286.

Giaquinta, R. T., and Geiger, D. R. (1977) Mechanism of cyanide inhibition of phloem translocation. Plant Physiol. 59: 178–180.

Knoblauch, M., and Oparka, K. (2012) The structure of the phloem—Still more questions than answers. Plant J. 70: 147–156.

Knoblauch, M., and van Bel, A. J. E. (1998) Sieve tubes in action. Plant Cell 10: 35–50.

Mullendore, D. L., Windt, C. W., Van As, H., and Knoblauch, M. (2010) Sieve tube geometry in relation to phloem flow. Plant Cell 22: 579–593.

Münch, E. (1930) Die Stoffbewegungen in der Pflanze. Gustav Fischer, Jena, Germany.

Nobel, P. S. (2005) Physicochemical and Environmental Plant Physiology, 3rd ed., Academic Press, San Diego, CA.

Patrick, J. W. (2013a) Does Don Fisher’s high-pressure manifold model account for phloem transport and resource partitioning? Front. Plant Sci. 4: 184. [DOI: 10.3389/fpls.2013.00184]

Patrick, J. W. (2013b) Fundamentals of phloem transport physiology. In Phloem: Molecular Cell Biology, Systemic Commuinication, Biotic Interactions, G. A. Thompson and A. J. E. van Bel, eds., John Wiley & Sons, Hoboken, NJ.

Sovonick-Dunford, S., Lee, D., and Zimmermann, M. (1981) Direct and indirect measurements of phloem turgor pressure in white ash. Plant Physiol. 68: 121–126.

Turgeon, R. (2010) The puzzle of phloem pressure. Plant Physiol. 154: 578–581.

Wright, J. P., and Fisher, D. B. (1980) Direct measurement of sieve tube turgor pressure using severed aphid stylets. Plant Physiol. 65: 1133–1135.

Zimmermann, M. H., and Milburn, J. A., eds. (1975) Transport in Plants, Vol. 1: Phloem Transport (Encyclopedia of Plant Physiology, New Series). Springer, New York.

Phloem Loading

Chen, L.-Q., Qu, X.-Q., Hou, B.-H., Sosso, D., Osorio, S., Fernie, A. R., and Frommer, W. B. (2012) Sucrose efflux mediated by SWEET proteins as a key step for phloem transport. Science 335: 207–211.

Evert, R. F., and Mierzwa, R. J. (1985) Pathway(s) of assimilate movement from mesophyll cells to sieve tubes in the Beta vulgaris leaf. In Phloem Transport. Proceedings of an International Conference on Phloem Transport, Asilomar, CA, J. Cronshaw, W. J. Lucas, and R. T. Giaquinta, eds. Liss, New York, pp. 419–432.

Fondy, B. R. (1975) Sugar selectivity of phloem loading in Beta vulgaris, vulgaris L. and Fraxinus americanus, americana L. Ph.D. diss., University of Dayton, Dayton, OH.

Gamalei, Y. V. (1985) Features of phloem loading in woody and herbaceous plants. Fiziologiya Rastenii (Moscow) 32: 866–875.

Geiger, D. R., Giaquinta, R. T., Sovonick, S. A., and Fellows, R. J. (1973) Solute distribution in sugar beet leaves in relation to phloem loading and translocation. Plant Physiol. 52: 585–589.

Grusak, M. A., Beebe, D. U., and Turgeon, R. (1996) Phloem loading. In Photoassimilate Distribution in Plants and Crops: Source–Sink Relationships, E. Zamski and A. A. Schaffer, eds., Dekker, New York, pp. 209–227.

Liesche, J., and Schulz, A. (2012) In vivo quantification of cell coupling in plants with different phloem loading strategies. Plant Physiol. 159: 355–365.

Liesche, J., and Schulz, A. (2013) Modeling the parameters for plasmodesmatal sugar filtering in active symplasmic phloem loaders. Front. Plant Sci. 4: 207. [DOI: 10.3389/fpls.2013.00207]

Rennie, E. A., and Turgeon, R. (2009) A comprehensive picture of phloem loading strategies. Proc. Natl. Acad. Sci. USA 106: 14163–14167.

Slewinski, T. L., Zhang, C., and Turgeon, R. (2013) Structural and functional heterogeneity in phloem loading and transport. Front. Plant Sci. 4: 244. [DOI: 10.3389/fpls.2013.00244]

Turgeon, R., Beebe, D. U., and Gowan, E. (1993) The intermediary cell: Minor-vein anatomy and raffinose oligosaccharide synthesis in the Scrophulariaceae. Planta 191:446-456.

van Bel, A. J. E. (1992) Different phloem-loading machineries correlated with the climate. Acta Bot. Neerl. 41: 121–141.

van Bel, A. J. E., Gamalei, Y. V., Ammerlaan, A., and Bik, L. P. M. (1992) Dissimilar phloem loading in leaves with symplasmic or apoplasmic minor-vein configurations. Planta 186: 518–525.

Voitsekhovskaja, O. V., Rudashevskaya, E. L., Demchenko, K. N., Pakhomova, M. V, Batashev, D. R., Gamalei, Y. V., Lohaus, G., and Pawlowski, K. (2009) Evidence for functional heterogeneity of sieve element-companion cell complexes in minor vein phloem of Alonsoa meridionalis. J. Exp. Bot. 60: 1873–1883.

Zhang, C. and Turgeon, R. (2009) Downregulating the sucrose transporter VpSUT1 in Verbascum phoeniceum does not inhibit phloem loading. Proc. Natl. Acad. Sci. USA 106: 18452–18457.

Phloem Unloading and Sink-to-Source Transition

Hayes, M. A., Davies, C., and Dry, I. B. (2007) Isolation, functional characterization, and expression analysis of grapevine (Vitis vinifera L.) hexose transporters: Differential roles in sink and source tissues. J. Exp. Bot. 58: 1985–1997.

McGarry, R. C., and Ayre, B. G. (2008) A DNA element between At4g28630 and At4g28640 confers companion-cell specific expression following the sink-to-source transition in mature minor vein phloem. Planta 228: 839–849.

Patrick, J. W. (2013b) Fundamentals of phloem transport physiology. In Phloem: Molecular Cell Biology, Systemic Commuinication, Biotic Interactions, G. A. Thompson and A. J. E. van Bel, eds., John Wiley & Sons, Hoboken, NJ.

Roberts, A. G., Santa Cruz, S., Roberts, I. M., Prior, D. A. M., Turgeon, R., and Oparka, K. J. (1997) Phloem unloading in sink leaves of Nicotiana benthamiana: Comparison of a fluorescent solute with a fluorescent virus. Plant Cell 9: 1381–1396.

Schneidereit, A., Imlau, A., and Sauer, N. (2008) Conserved cis-regulatory elements for DNA-binding-with-one-finger and homeo-domain-leucine-zipper transcription factors regulate companion cell-specific expression of the Arabidopsis thaliana SUCROSE TRANSPORTER 2 gene. Planta 228: 651–662.

Turgeon, R. (2006) Phloem loading: How leaves gain their independence. Bioscience 56: 15–24.

Turgeon, R., and Webb, J. A. (1973) Leaf development and phloem transport in Cucurbita pepo: Transition from import to export. Planta 113: 179–191.

Photosynthate Distribution: Allocation and Partitioning

Dai, Z. W., Wang, L. J., Zhao, J. Y., Fan, P. G., and Li, S. H. (2007) Effect and after-effect of water stress on the distribution of newly-fixed ¹⁴C-photoassimilate in micropropagated apple plants. Environ. Exp. Bot. 60: 484–494.

Fondy, B. R., and Geiger, D. R. (1980) Effect of rapid changes in sink–source ratio on export and distribution of products of photosynthesis in leaves of Beta vulgaris L. and Phaseolus vulgaris L. Plant Physiol. 66: 945–949.

Jeuffroy, M.-H., and Warembourg, F. R. (1991) Carbon transfer and partitioning between vegetative and reproductive organs in Pisum sativum L. Plant Physiol. 97: 440–448.

Koch, K. E. (1996) Carbohydrate-modulated gene expression in plants. Annu. Rev. Plant Physiol. Plant Mol. Biol. 47: 509–540.

Preiss, J. (1982) Regulation of the biosynthesis and degradation of starch. Annu. Rev. Plant Physiol. 33: 431–454.

Schulz, A. (1994) Phloem transport and differential unloading in pea seedlings after source and sink manipulations. Planta 192: 239–248.

Thorne, J. H., and Koller, H. R. (1974) Influence of assimilate demand on photosynthesis, diffusive resistances, translocation, and carbohydrate levels of soybean leaves. Plant Physiol. 54: 201–207.

Transport of Signaling Molecules

Ainsworth, E. A. and Bush, D. R. (2011) Carbohydrate export from the leaf: A highly regulated process and target to enhance photosynthesis and productivity. Plant Physiol. 155: 64–69.

Eveland, A. L., and Jackson, D. P. (2012) Sugars, signalling, and plant development. J. Exp. Bot. 63: 3367–3377.

Gomez, G., Torres, H., and Pallas, V. (2005) Identification of translocatable RNA-binding phloem proteins from melon, potential components of the long-distance RNA transport system. Plant J. 41: 107–116.

Hackel, A., Schauer, N., Carrari, F., Fernie, A. R., Grimm, B., and Kuehn, C. (2006) Sucrose transporter LeSUT1 and LeSUT2 inhibition affects tomato fruit development in different ways. Plant J. 45: 180–192.

Haywood, V., Yu, T.-S., Huang, N.-C., and Lucas, W. J. (2005) Phloem long-distance trafficking of GIBBERELLIC ACID-INSENSITIVE RNA regulates leaf development. Plant J. 42: 49–68.

Huang, N.-C., and Yu, T.-S. (2009) The sequences of Arabidopsis GA-INSENSITIVE RNA constitute the motifs that are necessary and sufficient for RNA long-distance trafficking. Plant J. 59: 921–929.

Kehr, J., and Buhtz, A. (2008) Long distance transport and movement of RNA through the phloem. J. Exp. Bot. 59: 85–92.

Koch, K. E. (1996) Carbohydrate-modulated gene expression in plants. Annu. Rev. Plant Physiol. Plant Mol. Biol. 47: 509–540.

Oparka, K. J., and Santa Cruz, S. (2000) The great escape: Phloem transport and unloading of macromolecules. Annu. Rev. Plant Physiol. Plant Mol. Biol. 51: 323–347.

Stadler, R., Wright, K. M., Lauterbach, C., Amon, G., Gahrtz, M., Feuerstein, A., Oparka, K. J., and Sauer, N. (2005) Expression of GFP-fusions in Arabidopsis companion cells reveals non-specific protein trafficking into sieve elements and identifies a novel post-phloem domain in roots. Plant J. 41: 319–331.

Yoo, S.-C., Chen, C., Rojas, M., Daimon, Y., Ham, B.-K., Araki, T., and Lucas, W. J. (2013) Phloem long-distance delivery of FLOWERING LOCUS T (FT) to the apex. Plant J. 75: 456–468.

Web Topics

Aki, T., Shigyo, M., Nakano, R., Yoneyama, T., and Yanagisawa, S. (2008) Nano scale proteomics revealed the presence of regulatory proteins including three FT-like proteins in phloem and xylem saps from rice. Plant Cell Physiol. 49: 767-790.

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Banerjee, A. K., Chatterjee, M., Yu, Y., Suh, S.-G., Miller, W. A., and Hannapel, D. J. (2006) Dynamics of a mobile RNA of potato involved in a long-distance signaling pathway. Plant Cell 18: 3443-3457.

Bortolotti, C., Murillo, I., Fontanet, P., Coca, M., and San Segundo, B. (2005) Long-distance transort of the maize pathogenesis-related PRms protein through the phloem in transgenic tobacco plants. Plant Sci. 168: 813–821.

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Giaquinta, R. (1976) Evidence for phloem loading from the apoplast. Chemical modification of membrane sulfhydryl groups. Plant Physiol. 57: 872–875.

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Gomez, G., Torres, H., and Pallas, V. (2005) Identification of translocatable RNA-binding phloem proteins from melon, potential components of the long-distance RNA transport system. Plant J. 41: 107-116.

Gottwald, J. R., Krysan, P. J., Young, J. C., Evert, R. F., and Sussman, M. R. (2000) Genetic evidence for the in planta role of phloem-specific plasma membrane sucrose transporters. In: Proceedings of the National Academy of Sciences of the United States of America. 97 (25): 13979-13984.

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Haywood, V., Yu, T.-S., Huang, N.-C., and Lucas, W. J. (2005) Phloem long-distance trafficking of GIBBERELLIC ACID-INSENSITIVE RNA regulates leaf development. Plant J. 42: 49-68.

Imlau, A., Truernit, E., and Sauer, N. (1999) Cell-to-cell and long-distance trafficking of the green fluorescent protein in the phloem and symplastic unloading of the protein into sink tissues. Plant Cell 11: 309–322.

Joy, K. W. (1964) Translocation in sugar beet. I. Assimilation of ¹⁴CO₂ and distribution of materials from leaves. J. of Exper. Bot. 15: 485–494.

Kehr, J., and Buhtz, A. (2008) Long distance transport and movement of RNA through the phloem. J. Exp. Bot. 59: 85-92.

King, R. W., and Zeevaart, J. A. D. (1974) Enhancement of phloem exudation from cut petioles by chelating agents. Plant Physiol. 53: 96–103.

Koch, K. E. (1996) Carbohydrate-modulated gene expression in plants. Annu. Rev. Plant Physiol. Plant Mol. Biol. 47: 509–540.

Krapp, A., and Stitt, M. (1995) An evaluation of direct and indirect mechanisms for the "sink-regulation" of photosynthesis in spinach: Changes in gas exchange, carbohydrates, metabolites, enzyme activities and steady-state transcript levels after cold-girdling source leaves. Planta 195: 313–323.

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Mason, T. G., and Lewin, C. J. (1926) On the rate of carbohydrate transport in the greater yam, Dioscorea alata. Sci. Proc. R. Dublin Soc. 18: 203–205.

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Stadler, R., Wright, K. M., Lauterbach, C., Amon, G., Gahrtz, M., Feuerstein, A., Oparka, K. J., and Sauer, N. (2005) Expression of GFP-fusions in Arabidopsis companion cells reveals non-specific protein trafficking into sieve elements and identifies a novel post-phloem domain in roots. Plant J. 41: 319-331.

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Thompson, M. V. and Wolniak, S. M. (2008) A plasma membrane-anchored fluorescent protein fusion illuminates sieve element plasma membranes in Arabidopsis and tobacco. Plant Physiol. 146: 1599-1610.

Tournier, B., Tabler, M., and Kalantidis, K. (2006) Phloem flow strongly influences the systemic spread of silencing in GFP Nicotiana benthamiana plants. Plant J. 47: 383-394.

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