Effects of bacteria on enhanced metal uptake of the Cd/Zn-hyperaccumulating plant, Sedum alfredii.
To investigate the effects of bacteria (Burkholderia cepacia) on metal uptake by the hyperaccumulating plant, Sedum alfredii, a hydroponic experiment with different concentrations of Cd and Zn was conducted. It was found that inoculation of bacteria on S. alfredii significantly enhanced plant growth (up to 110% with Zn treatment), P (up to 56.1% with Cd treatment), and metal uptake (up to 243% and 96.3% with Cd and Zn treatment, respectively) in shoots, tolerance index (up to 134% with Zn added treatment), and better translocation of metals (up to 296% and 135% with Cd and Zn treatment, respectively) from root to shoot. In the ampicillin added treatment with metal addition, stimulation of organic acid production (up to an increase of 133% of tartaric acid with Cd treatment) by roots of S. alfredii was observed. The secretion of organic acids appears to be a functional metal resistance mechanism that chelates the metal ions extracellularly, reducing their uptake and subsequent impacts on root physiological processes.
Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Hong Kong SAR, PR China.
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Li
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Ye
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Wong
D000667:Ampicillin; D000900:Anti-Bacterial Agents; D018533:Biomass; D016956:Burkholderia cepacia / Q000502:physiology*; D002104:Cadmium / Q000378:metabolism*; D002244:Carbon / Q000032:analysis; D004553:Electric Conductivity; D005122:Exudates and Transudates / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D018527:Hydroponics; D010758:Phosphorus / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology* / Q000502:physiology; D031963:Sedum / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D015032:Zinc / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D002104:Cadmium; D010758:Phosphorus; D002244:Carbon; D000667:Ampicillin; D015032:Zinc