Nanoparticle titanium dioxide affects the growth and microRNA expression of switchgrass (Panicum virgatum).

Nanoparticle TiO is a common chemical used in daily life. As increasing usage of TiO, it is becoming a potentially dangerous contaminant to the environment. However, the impact of TiO is not well understood. In this paper, switchgrass was employed to investigate the impacts of nanoparticle TiO on plant growth and development as well as the potential impact on the expression of microRNAs (miRNAs). TiO significantly affected switchgrass seed generation as well as plant growth and development in a dose-dependent manner. Particularly, TiO significantly inhibited root development. miRNA expressions were also significantly altered. Nanoparticle TiO may regulate plant development through controlling the expression of certain miRNAs. Among the 16 tested miRNAs, the expression of some miRNAs, such as miR390 and miR399 was increased with increasing TiO concentrations; the expression of some miRNAs, such as miR169 was decreased with increasing TiO concentrations; the other miRNAs show different expression patterns.