Copper oxide nanoparticle mediated DNA damage in terrestrial plant models
Bryant C. Nelson, Donald H. Atha, Elijah J. Petersen, Huanhua Wang, Danielle Cleveland, Richard D. Holbrook, Pawel Jaruga, M Miral Dizdar, Baoshan Xing
Engineered nanoparticles, due to their unique electrical, mechanical and catalytic properties, are presently found in many commercial products and will be intentionally or inadvertently released at increasing concentrations into the natural environment. Metal and metal-oxide based nanomaterials have been shown to act as mediators of DNA damage in mammalian cells, organisms and even in bacteria, but the molecular mechanisms through which this occurs are poorly understood. For the first time, we report that copper oxide nanoparticles induce DNA damage in agricultural and grassland plants. Significant accumulation of oxidatively-modified, mutagenic DNA lesions (7,8-dihydro-8-oxoguanine; 2,6-diamino-4-hydroxy-5-formamidopyrimidine; 4,6-diamino-5-formamidopyrimidine), and strong plant growth inhibition was observed for radish (Raphanus sativus), perennial ryegrass (Lolium perenne) and annual ryegrass (Lolium rigidum) under controlled laboratory conditions. Lesion accumulation levels mediated by copper ions and macroscale copper particles were measured in tandem to clarify the mechanisms of DNA damage. To our knowledge this is the first evidence of multiple DNA lesion formation and accumulation in plants. These findings provide impetus for future investigations on nanoparticle-mediated DNA damage and repair mechanisms in plants.