Metal Nanoparticles-Mediated Changes on Gene Expressions and Physiological Parameters of Capsicum annuum L.

Abstract

Objective: The uptake and accumulation of nanoparticles by plants create a potential threat for human health in cases where humans consume the plants. The aim of the study was to analyze the potential beneficial or inhibitory effects of nAl2O3 and nZnO on Capsicum annuum L. (pepper)'s germination, root growth, and expression levels of aquaporin and dehydrin genes. Material and Method: Different concentrations (0.5, 2.5, or 5.0 mM) of nAl2O3 and nZnO were used for the germination of pepper seeds. ICP-MS analysis was performed to determine ion contents in nanoparticle-treated pepper plants. Levels of aquaporin and dehydrin gene expressions were analyzed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results: The pepper germination was not affected by nanoparticle applications. While nAl2O3 treatments did not change root growth, higher concentrations of nZnO negatively affected root length and root number. In particular, the application of 0.5 mM nZnO significantly upregulated aquaporin and dehydrin gene expressions in roots. Downregulation of dehydrin gene expression occurred in stems and roots after exposure to nAl2O3 treatments. Conclusion: The gene expression alterations and changes of growth parameters showed especially nZnO have potentially phytotoxic for pepper plants. Moreover, expression analysis suggested that the tested genes may play roles in response to the nanoparticle-based abiotic stress.