Credit: © 2009 ACS

Some nanomaterials are known to penetrate the cell walls of plants and there is interest in using nanoparticles as delivery agents in agriculture and horticulture. However, it is more difficult for nanomaterials to get into plant seeds because they have thicker walls than plant cells, so the effects of nanomaterials on the germination of plant seeds remain unknown. Now researchers at the University of Arkansas have shown that multi-walled carbon nanotubes can penetrate tomato seeds and accelerate the sprouting process1.

Mariya Khodakovskaya, Alexandru Biris and colleagues immersed tomato seeds in standard agar medium supplemented with different concentrations of carbon nanotubes and examined their germination patterns. Seeds supplemented with nanotubes had similar root lengths to untreated seeds but grew faster, had greater biomasses and longer stems (see figure). Furthermore, seeds exposed to nanotubes were moister than the unexposed ones, suggesting that the carbon nanotubes had enhanced the uptake of water. Raman spectroscopy revealed that the nanotubes penetrated the seeds and roots of developed plants.

Although the mechanisms for increased water uptake by the nanotube-treated seeds remain unclear, and possible side effects still have to be investigated, the use of nanotubes for accelerating plant growth could open up new avenues in biofuel research.