Summary
The structure of leaf minor veins in 700 species from 140 families of dicotyledons, monocotyledons and conifers has been studied by light and electron microscopy. The presence of several structural types of minor veins has been shown. The main types are open and closed veins characteristic of trees and herbs, respectively. These vein types differ by the structure of intermediate cells, and by the mechanisms of phloem loading and sugar transport. Most woody plants have intermediate cells with numerous plasmodesmal fields, symplastic transport as the main phloem loading mechanism, as well as oligosaccharides and other complex sugars as the main phloem transport substances. By contrast, the majority of herbs have intermediate cells without plasmodesmal connections, and apoplastic loading of sucrose occurs only by membrane proton cotransport. The closed type is divided into three subtypes, differing in the degree of development of the structures used for sugar uptake from the apoplast. A list of the plants investigated with their vein types is given. The evolution of the minor vein structure and phloem loading mechanism are discussed in relation to the evolution of life forms of higher plants.
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References
Cataldo DA (1974) Vein loading: the role of the symplast in intercellular transport of carbohydrate between the mesophyll and minor veins of tobacco leaves. Plant Physiol 53: 912–917
Delrot S, Bonnemain JL (1981) Involvement of protons as a substrate for the sucrose carrier during phloem loading inVicia faba leaves. Plant Physiol 67: 560–564
Erwee MG, Goodwin PB (1985) Symplast domains in extrastelar tissues ofEgeria densa Planch. Planta 163: 9–19
Erwee MG, Goodwin PB, van Bel AIE (1985) Cell-cell communication in the leaves ofCommelina eyanea and other plants. Plant Cell Environ 8: 173–178
Esau K (1967) Minor veins inBeta leaves: structure related to function. Proc Am Phil Soc 11: 219–233
Esau K, Hoefert LL (1971) Composition and fine structure of minor veins inTetragonia leaf. Protoplasma 72: 237–253
Evert RF (1980) Vascular anatomy of angiospermous leaves, with special consideration of the maize leaf. Ber Dtsch Bot Ges 93: 43–55
Evert RF (1984) Comparative structure of phloem. In: Contemporary problems in plants anatomy, Academic Press, New York, pp 145–234
Evert RF, Eschrich W, Heyser W (1977) Distribution and structure of the plasmodesmata in mesophyll and bundlesheath cells ofZea mays L. Planta 136: 77–89
Fischer A (1884) Untersuchungen über das Siebröhren-System der Cucurbitaceen. Berlin
Fisher DG (1986) Ultrastructure, plasmodesmatal frequency, and solute concentration in green areas of variegatedColeus blumei Benth. leaves. Planta 169: 141–152
Fisher DG, Evert RF (1982) Studies on the leaf ofAmaranthus retroflexus (Amaranthaceae): ultrastructure, plasmodesmatal frequency, and solute concentration in relation to phloem loading. Planta 155: 377–387
Gamalei YV (1974) The symplastic connections inFraxinus minor veins. Botan. Zhurn. (Leningrad) 59: 980–988 (in Russian)
Gamalei YV (1985) Phloem loading in woody and herbaceous plants. Plant Physiol (Moscow) 32: 866–876 (in Russian)
Geiger DR, Giaquinta RT, Sovonick SA, Fellows RJ (1973) Solute distribution in sugar beet leaves in relation to phloem loading and translocation. Plant Physiol 52: 585–589
Giaquinta RT (1983) Phloem loading of sucrose. Ann Rev Plant Physiol 34: 347–387
Hendrix JE (1973) Translocation of sucrose by squash plants. Plant Physiol. 52: 688–689
Kursanov AL (1976) Assimilate transport in plants. Nauka, Moscow (in Russian)
Kursanov AL, Brovchenko MI (1970) Sugars in the free space of leaf plates: their origin and possible involvement in transport. Can J Bot 48: 1243–1250
Madore MA, Oross, JW, Lucas WJ (1986) Symplastic transport inIpomoea tricolor source leaves. Plant Physiol 82: 432–442
Oross JW, Grusak MA, Lucas WJ (1986) Regulation of long distance translocation in sugar beet: structural aspects, In: Phloem transport. Alan R Liss Inc, New York, pp 477–486
Pate JS, Gunning BES (1969) Vascular transfer cells in angiosperm leaves — a taxonomic and morphological survey. Protoplasma 68: 135–156
Schmitz K, Holthaus U (1986) Are sucrosyl-oligosaccharides synthesized in mesophyll protoplasts of mature leaves ofCucumis melo? Planta 169: 529–535
Schmitz K, Cuypers B, Moll M (1987) Pathway of assimilate transfer between mesophyll cells and minor veins in leaves ofCucumis melo L. Planta 171: 19–29
Terry BR, Robards AW (1987) Hydrodynamic radius alone governs the mobility of molecules through plasmodesmata. Planta 171: 145–158
Turgeon R, Webb JA, Evert RF (1975) Ultrastructure of minor veins inCucurbita pepo leaves. Protoplasma 83: 217–232
Tyree MT (1970) The symplast concept. A general theory of symplastic transport according to the thermodynamics of irreversible processes. J Theor Biol 26: 181–214
Watson L, Pate JS, Gunning BES (1977) Vascular transfer cells in leaves of Leguminosae — Papilionoideae. Bol J Linn Soc 74: 123–130
Ziegler H (1974) Biochemical aspects of phloem transport. Symp Soc Exp Biol 28: 43–62
Zimmermann MH, Ziegler H (1975) List of sugars and sugar alcohols in sieve-tube exudates. In: Transport in plants, vol. 1. Springer, Berlin Heidelberg New York, pp 480–496
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Gamalei, Y. Structure and function of leaf minor veins in trees and herbs. Trees 3, 96–110 (1989). https://doi.org/10.1007/BF01021073
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DOI: https://doi.org/10.1007/BF01021073