Effect of Glomus Mosseae from Lead Uptake by the Vetiveria Zizanioides

Summer Barber, Mandakini J. Patel, Rupali Datta, and Dibyendu Sarkar
Environmental Geochemistry Laboratory, University of Texas at San Antonio, San Antonio, TX

Arbuscular mycorrhizal (AM) fungi enhance the nutritional state of the host plants they colonize by acquiring phosphate, micronutrients and water for the host plants. Similarly, heavy metals are taken up via the fungal hyphae and can be transported to the plant. In some cases mycorrhizal plants show enhanced heavy metal uptake and root-to-shoot transport (phytoextraction) while in others AM fungi contribute to heavy metal immobilization within the soil (phytostabilization). Lead is a major soil contaminant in many neighbourhoods in San Antonio. The major source of lead contamination is lead based paint-contaminated older homes in the inner city. In addition, numerous public, private and military shooting ranges exist in San Antonio, which constitute another source of lead contamination. Phytoremediation has been identified as an inexpensive and environment-friendly method to cleanup lead contaminated soils. Vetiver grass (Vetiveria zizanioides) is a fast-growing, high biomass plant that has been identified as a promising lead-accumulating plant. However, in the presence of soil phosphorous, lead is readily precipitated, making it unavailable for plant uptake. The AM fungus Glomus mossea has shown the potential of solubilizing the lead, increasing its phytoavailability. In this study, spores of Glomus mosseae were grown on agar plates in dark at 25°C. Mycelial growth was observed after 14 days. These mycelia were transferred to a sterile hydroponics setup in which vetiver grass was grown. Glomus infection was seen in vetiver roots after 10 days, which was confirmed by histological staining using Aniline Blue and by PCR using Glomus specific primers. Infected plants showed significantly higher lead uptake, which indicates the promise of this method to develop to a low-cost lead phytoremediation technology in future.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas