Increased use of engineered nanoparticles (NPs) is likely to result in their continued release into the environment. Some nanoparticles including zinc oxide nanoparticles (ZnO-NPs) can be toxic to eukaryotic cells, but presently little is known about ZnO-NPs effects on plants and organisms symbiotically associated them. Under in vitro conditions, we examined the effect of 4 nm ZnO-NPs on carrots roots and arbuscular mycorrhizal fungi (AMF), which are obligate biotrophs that play an essential role in mineral uptake. During 4 weeks of incubation, roots in the control treatment (0μg ml-1 ZnO) grew 30 ± 8 cm, while growth was negligible with 50 μg ml-1 ZnO-NPs in the growing medium. To study the effect of ZnO-NPs on AMF, we used a bi-compartmental Petri dish system, where roots and AMF grew in one compartment and just the extraradical hyphae on the other. ZnO-NPs were only added to the hyphal compartment. Six weeks after the initiation of the experiment, controls showed high density of hyphae and spores, these densities were lower with 10 μg ml-1 ZnO-NPs, and minimal growth occurred at 50 μg ml-1. We are presently investigating the fate of the ZnO-NPs to elucidate mechanisms responsible for their toxicity.
Husler, Brian, "Effects of Zinc Oxide Nanoparticles on Carrot Roots and Arbuscular Mycorrhizae" (2014). College of Arts and Sciences Presentations. Paper 36.