Silica nanoparticles mediated insect pest management

Silicon (Si) accumulation differs greatly between plant species because of differences in Si uptake by the roots. Recently, a gene encoding a Si uptake transporter in rice, a typical Si-accumulating plant, was isolated. The beneficial effects of Si are mainly associated with its high deposition in plant tissues, enhancing their strength and rigidity. However, Si might play an active role in enhancing host resistance to plant diseases by stimulating defense reaction mechanisms. Because many plants are not able to accumulate Si at high enough levels to be beneficial, genetically manipulating the Si uptake capacity of the root might help plants to accumulate more Si and, hence, improve their ability to overcome biotic and abiotic stresses.

The uptake, bioaccumulation, biotransformation, and risks of nanomaterials (NMs) for food crops are still not well understood. Very few NMs and plant species have been studied, mainly at the very early growth stages of the plants. Most of the studies, except one with multiwalled carbon nanotubes performed on the model plant Arabidopsis thaliana and another with ZnO nanoparticles (NPs) on ryegrass, reported the effect of NMs on seed germination or 15-day-old seedlings. Very few references describe the biotransformation of NMs in food crops, and the possible transmission of the NMs to the next generation of plants exposed to NMs is unknown. The possible biomagnification of NPs in the food chain is also unknown.