Stowers, Cheyenne Elise (2017-12). The Impact of the Rhizosphere Microbial Community on the Interactions of Engineered Nanoparticles with Plants. Master's Thesis. Thesis uri icon

abstract

  • The use of engineered nanoparticles (ENPs) has drastically increased, resulting in the release of these particles into the environment; raising concerns over the impacts this could have on human food safety. Two ENPs of interest are cerium oxide nanoparticles (CeOv2 NPs) and graphene oxide nanoparticles (GO NPs). Both of these ENPs have shown that they can impact agricultural crops, but the role soil microorganisms in the rhizosphere can have in ENPs impacting plants is understudied. The rhizosphere contains microbes that are highly influenced by exudates produced from the roots. Interaction between ENPs and the rhizosphere community is important for understanding the potential environmental consequences. The goals of this study were to: (1) assess the effects of the initial microbial community on the interactions of ENPs with plants, and (2) understand the physical and chemical transformation of ENPs in the rhizosphere and within plant tissues, and its impact on plant health. This was done by administering GO and CeOv2 NPs to soybeans at concentration levels of 0, 100 mg/kg, and 500 mg/kg. Two soil conditions were used, initially sterilized and unsterilized. Sterilizing the soil was used to eliminate the current microbial community. The GO study did not show any interactions between the nanoparticles and indigenous microbial community affecting the soybeans, but some physiological parameters were independently impacted by soil conditions and concentration levels. The CeOv2 NP samples showed significant interactions in parameters associated with photosynthetic process, as well as in biomass and total cerium accumulation. The presence of cerium significantly impacted the production of nodules on the soybean roots, leading to the conclusion that the CeOv2 NPs were influencing nitrogen uptake by the soybeans. The results showed that CeOv2 NPs significantly interact with the microbial community in the rhizosphere in their interactions with plants and GO NPs probably did not
  • The use of engineered nanoparticles (ENPs) has drastically increased, resulting in the release of these particles into the environment; raising concerns over the impacts this could have on human food safety. Two ENPs of interest are cerium oxide nanoparticles (CeOv2 NPs) and graphene oxide nanoparticles (GO NPs). Both of these ENPs have shown that they can impact agricultural crops, but the role soil microorganisms in the rhizosphere can have in ENPs impacting plants is understudied. The rhizosphere contains microbes that are highly influenced by exudates produced from the roots. Interaction between ENPs and the rhizosphere community is important for understanding the potential environmental consequences.

    The goals of this study were to: (1) assess the effects of the initial microbial community on the interactions of ENPs with plants, and (2) understand the physical and chemical transformation of ENPs in the rhizosphere and within plant tissues, and its impact on plant health. This was done by administering GO and CeOv2 NPs to soybeans at concentration levels of 0, 100 mg/kg, and 500 mg/kg. Two soil conditions were used, initially sterilized and unsterilized. Sterilizing the soil was used to eliminate the current microbial community. The GO study did not show any interactions between the nanoparticles and indigenous microbial community affecting the soybeans, but some physiological parameters were independently impacted by soil conditions and concentration levels. The CeOv2 NP samples showed significant interactions in parameters associated with photosynthetic process, as well as in biomass and total cerium accumulation. The presence of cerium significantly impacted the production of

    nodules on the soybean roots, leading to the conclusion that the CeOv2 NPs were influencing nitrogen uptake by the soybeans. The results showed that CeOv2 NPs significantly interact with the microbial community in the rhizosphere in their interactions with plants and GO NPs probably did not

publication date

  • December 2017