Does boron play only a structural role in the growing tissues of higher plants?

  • Patrick H. Brown
  • Hening Hu
Part of the Developments in Plant and Soil Sciences book series (DPSS, volume 78)


In species in which boron (B) mobility is limited, B deficiency only occurs in growing plant organs. As a consequence of the highly localized patterns of plant growth and the general immobility of B it has been extremely difficult to determine the primary function of B in plants. In species in which B is phloem mobile, the removal of B from the growth medium results in the depletion of B present in mature leaves. Thus, it is possible to develop mature leaves with increasingly severe levels of B depletion, thereby overcoming the complications of experiments based on growing tissues. Utilizing this approach we demonstrate here that B depletion of mature plum (Prunus salicind) leaves did not result in any discernible change in leaf appearance, membrane integrity or photosynthetic capacity even though B concentrations were reduced to 6–8 µg/g dwt, which is less than 30% of the reported tissue B requirement. Boron depletion, however, results in a severe disruption of plant growth and metabolism in young growing tissues. This experimental evidence and theoretical considerations suggest that the primary and possibly sole function of B, is as a structural component of growing tissues.

Key words

Boron deficiency function membrane mobility photosynthesis 


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  1. Brown P H and Hu H 1996 Phloem mobility of boron is species dependent: evidence for phloem mobility in sorbitol-rich species. Ann. Bot. 77, 497–505.CrossRefGoogle Scholar
  2. Cakmak I, Kurz H and Marschner H 1995 Short-term effects of boron, germanium and high light intensity on membrane permeability in boron deficient leaves of sunflower. Physiol. Plant. 95, 11–18.CrossRefGoogle Scholar
  3. Dugger W M 1983 Boron in plant metabolism. In Encyclopedia of plant physiology. New series V15B. Inorganic plant nutrition. Eds. A Lauchli and R L Bieleski. pp 626–650. Springer-Verlag, Berlin.Google Scholar
  4. Findeklee P and Goldbach H E 1996 Rapid effects of boron deficiency on cell wall elasticity modulus in Cucurbita pepo roots. Bot. Acta. 109, 463–465.Google Scholar
  5. Heyes J A, White P J and Loughman B C 1991 The role of boron in some membrane characteristics of plant cells and protoplasts. In Current topics in plant biochemistry and physiology. V10. Eds. D D Randall, D G Blevins and C D Miles. pp 179–194. University of Missouri: the interdisciplinary plant biochemistry and physiology program, Columbia.Google Scholar
  6. Hirsch A M and Torrey J G 1980 Ultrastructural changes in sunflower root cells in relation to boron deficiency and added auxin. Can. J. Bot. 58, 856–866.CrossRefGoogle Scholar
  7. Hoagland D R and Arnon D I 1950 The water-culture method for growing plants without soil. Calif. Exp. Sta. Cir. 347. The College of Agriculture, University of California, Berkeley, CAGoogle Scholar
  8. Hu H and Brown P H 1994 Localization of boron in cell walls of squash and tobacco and its association with pectin. Evidence for a structural role of boron in the cell wall. Plant Physiol. 105, 681–689.PubMedGoogle Scholar
  9. Hu H, Penn S G, Lebrilla C B and Brown P H 1997 Isolation and characterization of soluble boron complexes in higher plants. Plant Physiol. 113, 649–655.PubMedCrossRefGoogle Scholar
  10. Ishii T and Matsunaga T 1996 Isolation and characterization of a boron-rhamnogalacturonan-II complex from cell walls of sugar beet pulp. Carbohydr. Res. 284, 1–9.CrossRefGoogle Scholar
  11. Kobayashi M, Matoh T and Azuma J-I 1996 Two chains of rhamnogalacturonan II are cross- linked by borate-diol ester bonds in higher plant cell walls. Plant Physiol. 110, 1017–1020.PubMedGoogle Scholar
  12. Krueger R W, Lovatt C J and Albert L S 1987 Metabolic requirement of Cucurbita pepo for boron. Plant Physiol. 83, 254–258.PubMedCrossRefGoogle Scholar
  13. Loomis W D and Durst R W 1992 Chemistry and biology of boron. Biofactors 3, 229–239.PubMedGoogle Scholar
  14. Lovatt C J and Dugger W M 1984 Boron. In Biochemistry of the essential ultratrace elements. Ed. E Frieden, pp 389–421. Plenum Press, New York.Google Scholar
  15. Lukaszewski K M, Blevins D G and Randall D D 1992 Asparagine and boric acid cause allantoate accumulation in soybean leaves by inhibiting manganese-dependent allantoate amidohydrolase. Plant Physiol. 99, 1670–1676.PubMedCrossRefGoogle Scholar
  16. Matoh T, Ishigaki K-I, Mizutani M, Matsunaga W and Takabe K 1992 Boron nutrition of cultured tobacco BY-2 cells. I. Requirement for and intracellular localization of boron and selection of cells that tolerate low levels of boron. Plant Cell Physiol. 33, 1135–1141.Google Scholar
  17. Matoh T, Ishigaki K-I, Kaori O and Azuma J-I 1993 Isolation and characterization of a boron- polysaccharide complex from radish roots. Plant Cell Physiol. 34, 639–642.Google Scholar
  18. Matoh T, Kawaguchi S and Kobayashi M 1996 Ubiquity of a borate-rhamnogalacturonan II complex in the cell walls of higher plants. Plant Cell Physiol. 37, 636–640.Google Scholar
  19. O’Neill M A, Warrenfeltz D, Kates K, Pellerin P, Doco T, Darvill A G and Albersheim P 1996 Rhamnogalacturonan-II, a pectic polysaccharide in the walls of growing plant cells, forms a dimmer that is covalently cross-linked by a borate ester. J. Biol. Chem. 271, 22923–22930.PubMedCrossRefGoogle Scholar
  20. Parr A J and Loughman B C 1983 Boron and membrane function in plants. In Metals and micronutrients: uptake and utilization by plants. Eds. D A Robb and W S A Pierpoint. pp 87–107. Academic Press, New York.Google Scholar
  21. Robertson G A and Loughman B C 1973 Rubidium uptake and boron deficiency in Vicia faba L. J. Exp. Bot. 24, 1046–1052.CrossRefGoogle Scholar
  22. Robinson J B 1986 Fruits, vines and nuts. In Plant analysis, an interpretation manual. Eds. D J Reuter and J B Robinson. pp 120–147. Inkata Press, Melbourne, Sydney.Google Scholar
  23. Shelp B J 1993 Physiology and biochemistry of boron in plants. In Boron and its role in crop production. Ed. U C Gupta. pp 53–85. CRC Press, Boca Raton.Google Scholar
  24. Yamauchi T, Hara T and Sonoda Y 1986 Distribution of calcium and boron in the pectin fraction of tomato leaf cell wall. Plant Cell Physiol. 27, 729–732.Google Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • Patrick H. Brown
    • 1
  • Hening Hu
    • 1
  1. 1.Department of PomologyUniversity of CaliforniaDavisUSA

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