Plant and Soil

, Volume 132, Issue 2, pp 187–196

Mobilization of cadmium and other metals from two soils by root exudates of Zea mays L., Nicotiana tabacum L. and Nicotiana rustica L.

  • M. Mench
  • E. Martin

DOI: 10.1007/BF00010399

Cite this article as:
Mench, M. & Martin, E. Plant Soil (1991) 132: 187. doi:10.1007/BF00010399


Soluble root exudates were collected from three plants (Nicotiana tabacum L., Nicotiana rustica L. and Zea mays L.), grown under axenic and hydroponic conditions, in order to study their metal-solubilizing ability for Cd and other cations (Cu, Fe, Mn, Ni, Zn). Nicotiana spp. and Zea mays L. root exudates differed markedly in C/N ratio, sugars vs. amino acids ratio and organic acids content. Metals from two soils were extracted with either root exudate solutions, containing equal amounts of organic carbon, or distilled water as control. In the presence or absence of root exudates, the solubility of Fe and Mn was much higher than of the four other metals tested. Root exudates increased the solubilities of Mn and Cu, whereas those of Ni and Zn were not affected. Root exudates of Nicotiana spp. enhanced the solubility of Cd. The extent of Cd extraction by root exudates (N. tabacum L. N. rustica L. Zea mays L.) was similar to the order of Cd bioavailability to these three plants when grown on soil. An increase in Cd solubility in the rhizosphere of apical root zones due to root exudates is likely to be an important cause of the relatively high Cd accumulation in Nicotiana spp.

Key words

cadmium copper extraction method iron maize manganese nickel root exudate tobacco zinc 

Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • M. Mench
    • 1
  • E. Martin
    • 1
  1. 1.Station d'Agronomie, Centre de Recherches de BordeauxI. N. R. A.Villenave d'Ornon CedexFrance

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