Plant growth promoting activity of an auxin and siderophore producing isolate of Streptomyces under saline soil conditions

World J Microbiol Biotechnol. 2012 Apr;28(4):1503-9. doi: 10.1007/s11274-011-0952-7. Epub 2011 Nov 19.

Abstract

A biocontrol Streptomyces isolate (C) was tested for its plant growth promoting qualities under saline conditions. Exposure to elevated osmotic strengths up to 300 mM NaCl increased dry weight and cfu/ml significantly. The isolate C produced indolyl-3-acetic acid (IAA) into the medium in the amount of 2.4 μg/ml. The amount of auxin increased after adding salt and reached to 4.7 μg/ml in 300 mM NaCl. Biosynthesis of siderophore was detectable and increased in presence of NaCl. Streptomyces isolate C showed good solubilization of tricalcium phosphate in culture medium with 92 mg/l. Solubilization decreased in presence of NaCl. Soil treatment with isolate C increased the growth and development of wheat plant in normal and saline conditions. In this treatment there were significant increases in germination rate, percentage and uniformity, shoot length and dry weight compared to the control. Applying the bacterial inocula increased the concentration of N, P, Fe and Mn in wheat shoots grown in normal and saline soil, but had non-significant effect on other micro and macronutrients concentrations. Results of this study show that Streptomyces isolate C has potential to be utilized as biofertilizer in saline soils.

MeSH terms

  • Biomass
  • Culture Media / chemistry
  • Indoleacetic Acids / metabolism*
  • Iron / analysis
  • Manganese / analysis
  • Nerve Growth Factors*
  • Nitrogen / analysis
  • Phosphorus / analysis
  • Plant Shoots / chemistry
  • Plant Shoots / growth & development
  • Salinity
  • Siderophores / metabolism*
  • Sodium Chloride / metabolism
  • Soil Microbiology*
  • Streptomyces / drug effects
  • Streptomyces / metabolism
  • Streptomyces / physiology*
  • Triticum / chemistry
  • Triticum / growth & development*

Substances

  • Culture Media
  • Indoleacetic Acids
  • Nerve Growth Factors
  • Siderophores
  • Phosphorus
  • Manganese
  • Sodium Chloride
  • Iron
  • Nitrogen