Abstract
We investigated the phytotoxicity of multiwalled carbon nanotubes (MWNTs) on lettuce regarding inhibition effect on plant growth development as well as cell damage on root and leaves. We have cultured the plant seedling of lettuce using Hoagland's Media treated with MWNTs hydroponically. After two weeks, we observed the toxic symptoms in the presence of MWNTs in a dose-dependent manner as compared to carbon black (CB). Statistically, MWNTs could inhibit the seed germination, plant growth and plant biomass. Microscopic analysis showed the attachment of MWNTs on the root surface area, deterioration of root tip and an image of penetration of MWNTs into plant cell wall. We also showed that MWNTs caused cell death on root and leaves. In situ detection of hydrogen peroxide has proposed the reactive oxygen species (ROS) for mechanism of toxic effect of MWNTs on lettuce.
