Cultivar and Metal-Specific Effects of Endophytic Bacteria in Helianthus tuberosus Exposed to Cd and Zn

Int J Mol Sci. 2017 Sep 21;18(10):2026. doi: 10.3390/ijms18102026.


Plant growth promoting endophytic bacteria (PGPB) isolated from Brassica napus were inoculated in two cultivars of Helianthus tuberosus (VR and D19) growing on sand supplemented with 0.1 mM Cd or 1 mM Zn. Plant growth, concentrations of metals and thiobarbituric acid (TBA) reactive compounds were determined. Colonization of roots of H. tuberosus D19 by Pseudomonas sp. 262 was evaluated using confocal laser scanning microscopy. Pseudomonas sp. 228, Serratia sp. 246 and Pseudomonas sp. 262 significantly enhanced growth of H. tuberosus D19 exposed to Cd or Zn. Pseudomonas sp. 228 significantly increased Cd concentrations in roots. Serratia sp. 246, and Pseudomonas sp. 256 and 228 resulted in significantly decreased contents of TBA reactive compounds in roots of Zn exposed D19 plants. Growth improvement and decrease of metal-induced stress were more pronounced in D19 than in VR. Pseudomonas sp. 262-green fluorescent protein (GFP) colonized the root epidermis/exodermis and also inside root hairs, indicating that an endophytic interaction was established. H. tuberosus D19 inoculated with Pseudomonas sp. 228, Serratia sp. 246 and Pseudomonas sp. 262 holds promise for sustainable biomass production in combination with phytoremediation on Cd and Zn contaminated soils.

Keywords: Helianthus tuberosus; green fluorescent protein; high biomass crop; metal contaminated soil; phytoremediation; plant growth promoting bacteria.

MeSH terms

  • Biodegradation, Environmental
  • Brassica napus / microbiology
  • Cadmium / metabolism*
  • Cadmium / toxicity
  • Endophytes / drug effects
  • Endophytes / growth & development
  • Endophytes / metabolism*
  • Genes, Reporter
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Helianthus / drug effects
  • Helianthus / microbiology
  • Microscopy, Confocal
  • Plant Roots / drug effects
  • Plant Roots / microbiology
  • Pseudomonas / drug effects
  • Pseudomonas / growth & development
  • Pseudomonas / metabolism*
  • Serratia / drug effects
  • Serratia / growth & development
  • Serratia / metabolism*
  • Soil Microbiology*
  • Soil Pollutants / metabolism*
  • Soil Pollutants / toxicity
  • Thiobarbiturates / metabolism
  • Zinc / metabolism*
  • Zinc / toxicity


  • Soil Pollutants
  • Thiobarbiturates
  • enhanced green fluorescent protein
  • Cadmium
  • Green Fluorescent Proteins
  • Zinc
  • thiobarbituric acid