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.
Li
W C
WC
Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Hong Kong SAR, PR China.
Ye
Z H
ZH
Wong
M H
MH
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