Abstract
Appreciable quantities of Zn are bound as Zn phytate (myo-inositol kis-hexaphosphate) within small vacuoles of cortical cells in the elongation zone of root tips of zinc tolerant Deschampsia caespitosa. These Zn/P-containing globular deposits have now been shown to occur in the roots of soybean, lucerne, lupins, tomato, rapeseed, cabbage, radish, wheat and maize. The globules are most frequent in the endodermis and pericycle but may also occur in the stele and inner cortex. The X-ray data again confirmed the presence of phytate with a relatively stable proportion of Zn and a species-dependent, variable, proportion of K, Mg and Ca to P.
Analysis of soybean plants by atomic absorption spectroscopy showed that the Zn concentration in the shoots doubled in response to an increase in Zn supply from 1 to 100 μM while the concentration of Zn in the root symplast was approximately 22 times greater than in the shoot, suggesting restricted transport to the shoot. It is suggested that the genetic expression of the capacity to bind heavy metals by means of phytate in endodermal cells may provide a strategy for keeping the above-ground content of heavy metals low. It may be possible to incorporate the trait into transformed roots that can be utilized for the treatment of industrial wastes.
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References
Baker A J M and Brooks R R 1989 Biorecovery 1, 81–126.
Campbell M, Dunn R, Ditterline R, Pickett S and Raboy 1991 J. Plant Nutrition 14, 925–937.
Cosgrove D J 1980 Inositol phosphates. Their chemistry, biochemistry and physiology. pp 1–191. Elsevier Publishing Co., Amsterdam, Oxford, New York.
Dixon K W, Kuo J, Pate J S 1983 Aust. J. Bot. 31, 85–103.
Godbold D L, Horst W J, Marschner H, Collins J C and Thurman D A 1983 Z. Pflanzenphys. 112, 315–324.
Godbold D L, Horst W J, Collins J C, Thurman D A and Marschner H 1984 J. Plant Physiol. 116, 59–69.
Grill E, Winnacker E L and Zenk M H 1985 Science 230, 674–676.
Harrison S J, Lepp N W and Phipps D A 1979 Z. Pflanzenphys. 94, 27–34.
Van Steveninck R F M, Van Steveninck M E, Fernando D R, Horst W J, Marschner H 1987 J. Plant Physiol. 131, 247–257.
Van Steveninck R F M, Van Steveninck M E, Wells A J and Fernando D R 1990 J. Plant Physiol. 137, 140–146.
Van Steveninck R F M and Van Steveninck M E 1991 Microanalysis. In Electron microscopy of plant cells. Eds J L Hall and C Hawes. pp 415–455. Academic Press, London.
Van Steveninck R F M, Van Steveninck M E and Fernando R 1992 Plant and Soil 146, 271–280.
Wagner G J and Krotz 1989 UCLA Symp. Mol. Cell Biol. (New Series) 98, 325–336.
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Van Steveninck, R.F.M., Babare, A., Fernando, D.R. et al. The binding of zinc in root cells of crop plants by phytic acid. Plant Soil 155, 525–528 (1993). https://doi.org/10.1007/BF00025099
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DOI: https://doi.org/10.1007/BF00025099