Pan Ke’s Group from the Institute for Advanced Study of Shenzhen University recently published a research paper titled The roles of silicon in combating cadmium challenge in the marine diatom Phaeodactylum tricornutum in an international authoritative journal called Journal of Hazardous Materials (Impact Factor 7.91, Chinese Academy of Sciences JCR, TOP)
Pan Ke’s group found in their researches that marine phytoplankton possess a sophisticated homeostatic network to counteract metal toxicity. Changes in environmental conditions such as ambient nutrient concentrations can significantly impact their intrinsic metal sensitivity. Previous studies have shown that silicate may be an environmental factor that limits the growth of marine diatoms, but few researchers paid attention to the impact of silicate levels on the resistance of marine diatom Phaeodactylum tricornutum to cadmium toxicity.
Thereby, Pan Ke’s group tried to evaluate the role of silicon (Si) in counteracting cadmium (Cd) toxicity in the marine diatom Phaeodactylum tricornutum in their studies. They first demonstrated that Si enrichment dramatically enhanced Cd tolerance and changed the Cd accumulation in the diatom. Their modeling suggested that Si-enriched cells adsorbed more Cd but had a higher Cd elimination rate than the Si-starved cells. Examinations by atomic force microscopy and X-ray photoelectron spectroscopy revealed that the Si-enriched cells had better silification and more SiO− in the cell walls, which markedly lowered the surface potential of the diatom cells and allowed them to attract more Cd. Although the Si-enriched cells tended to have a high Cd burden when facing Cd stress, they suppressed the increase of intracellular Cd by both down-regulating the influx transporter ZIP and up-regulating the efflux transporter ATPase5-1B. Pan Ke group’s study shows the significant roles Si plays in maintaining metal homeostasis and combating Cd challenge in marine diatoms.
The first authors of the paper are post-doctors Jie Ma and Beibei Zhou from the IAS of Shenzhen University, and the corresponding author is PI Pan Ke from the IAS. This work was supported by the grants from the General Projects and Youth Science Fund Project of the Natural Science Foundation of China, and the China Postdoctoral Science Foundation. Shenzhen University is the first completion unit.