Article
Phytoprotective influence of bacteria on growth and cadmium accumulation in the aquatic plant Lemna minor
Water Research
(2010)
Abstract
Certain plants are known to accumulate heavy metals, and can be used in remediation of
polluted soil or water. Plant-associated bacteria, especially those that are metal tolerant,
may enhance the total amount of metal accumulated by the plant, but this process is still
unclear. In this study, we investigated metal enhancement vs. exclusion by plants, and the
phytoprotective role plant-associated bacteria might provide to plants exposed to heavy
metal. We isolated cadmium-tolerant bacteria from the roots of the aquatic plant Lemna
minor grown in heavy metal-polluted waters, and tested these isolates for tolerance to
cadmium. The efficiency of plants to accumulate heavy metal from their surrounding
environment was then tested by comparing L. minor plants grown with added metal
tolerant bacteria to plants grown axenically to determine, whether bacteria associated with
these plants increase metal accumulation in the plant.
Unexpectedly, cadmium tolerance was not seen in all bacterial isolates that had been
exposed to cadmium. Axenic plants accumulated slightly more cadmium than plants
inoculated with bacterial isolates. Certain isolates promoted root growth, but overall,
addition of bacterial strains did not enhance plant cadmium uptake, and in some cases,
inhibited cadmium accumulation by plants. This suggests that bacteria serve a phytoprotective
role in their relationship with Lemna minor, preventing toxic cadmium from entering
plants.
Keywords
- Cadmium,
- Rhizosphere bacteria,
- Duckweed,
- Metal accumulation
Disciplines
Publication Date
2010
Citation Information
Julian Tyson, Lisa M. Stout, Elena N. Dodova and Klaus Nusslein. "Phytoprotective influence of bacteria on growth and cadmium accumulation in the aquatic plant Lemna minor" Water Research Vol. 44 (2010) p. 4970 - 4979 Available at: http://works.bepress.com/julian_tyson/144/