Novel impacts of functionalized multi-walled carbon nanotubes in plants: promotion of nodulation and nitrogenase activity in the rhizobium-legume system

Abstract

MWCNT treatment, which enhanced the above- and below-ground fresh biomass by 14% and 25% respectively at 28 dpi. Transmission electron microscopy images further indicated that MWCNTs penetrated the cell wall, and pierced through the cell membrane to be transmitted into the cytoplasm. In addition, gene expression analysis showed that the promotion of nodulation by MWCNTs was correlated with the up-regulation of certain genes involved in this signaling pathway. In particular, the expression of NIN, a crucial gene regulating the development of nodules, was significantly elevated 2-fold by MWCNTs at an early stage of nodulation. These findings are expected to facilitate the understanding and future utilization of MWCNTs in agriculture.