Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


Wheat gets boost from purified nanotubes

The introduction of purified carbon nanotubes appears to have a beneficial effect on the early growth of wheatgrass, according to Rice University scientists. But in the presence of contaminants, those same nanotubes could do great harm.

The Rice lab of chemist Andrew Barron grew wheatgrass in a hydroponic garden to test the potential toxicity of nanoparticles on the plant. To their surprise, they found one type of particle dispersed in water helped the plant grow bigger and faster.

They suspect the results spring from nanotubes' natural hydrophobic (water-avoiding) nature that in one experiment apparently facilitated the plants' enhanced uptake of water.

The research appears in the Royal Society of Chemistry journal Environmental Science: Nano.

The lab mounted the small-scale study with the knowledge that the industrial production of nanotubes will inevitably lead to their wider dispersal in the environment. The study cited rapid growth in the market for nanoparticles in drugs, cosmetic, fabrics, water filters and military weapons, with thousands of tons produced annually.

Despite their widespread use, Barron said few researchers have looked at the impact of environmental nanoparticles -- whether natural or man-made -- on plant growth.

The researchers planted wheatgrass seeds in multiple replicates in cotton wool and fed them with dispersions that contained raw single-walled or multi-walled nanotubes, purified single-walled nanotubes or iron oxide nanoparticles that mimicked leftover catalyst often attached to nanotubes. The solutions were either water or tetrahydrofuran (THF), an industrial solvent. Some of the seeds were fed pure water or THF as a control.

After eight days, the plantings showed that purified single-walled nanotubes in water enhanced the germination rate and shoot growth of wheatgrass, which grew an average of 13 percent larger than plants in plain water. Raw single- and multi-walled nanotubes and particles in either solution had little effect on the plants' growth, they found.

However, purified single-walled nanotubes in THF retarded plant development by 45 percent compared to single-walled nanotubes in water, suggesting the nanotubes act as a carrier for the toxic substance.

The concern, Barron said, is that if single-walled nanotubes combine with organic pollutants like pesticides, industrial chemicals or solvents in the environment, they may concentrate and immobilize the toxins and enhance their uptake by plants.

Nothing seen in the limited study indicated whether carbon nanotubes in the environment, and potentially in plants, will rise up the food chain and be harmful to humans, he said.

On the other hand, the researchers said it may be worth looking at whether hydrophobic substrates that mimic the positive effects observed in single-walled nanotubes could be used for high-efficiency channeling of water to seeds.

"Our work confirms the importance of thinking of nanomaterials as part of a system rather in isolation," Barron said. "It is the combination with other compounds that is important to understand."

Read the paper: Effect of raw and purified carbon nanotubes and iron oxide nanoparticles on the growth of wheatgrass prepared from the cotyledons of common wheat (Triticum aestivum).

Article source: Rice University.

Image credit: Pavan Raja/Rice University

News

New study shows producers where and how to grow cellulosic biofuel crops

According to a recent ruling by the United States Environmental Protection Agency, 288 million gallons of cellulosic biofuel must be blended into the U.S. gasoline supply in 2018. Although this figure is down slightly from last year, the industry is still growing at a modest pace. However, until now, producers have had to rely on incomplete information and unrealistic, small-scale studies in guiding their decisions about which feedstocks to grow, and where. A new multi-institution report provides practical agronomic data for five cellulosic feedstocks, which could improve adoption and increase production across the country.


Europe's lost forests: Coverage has halved over 6,000 years

More than half of Europe's forests have disappeared over the past 6,000 years thanks to increasing demand for agricultural land and the use of wood as a source of fuel, new research led by the University of Plymouth suggests.


The circadian clock sets the pace of plant growth

The recent award of the Nobel Prize in Physiology or Medicine to the three American researchers Hall, Rosbash and Young for their "discoveries of molecular mechanisms controlling the circadian rhythm" has greatly popularized this term -which comes from the Latin words "circa" (around of) and "die" (day)-. Thanks to the discoveries that these scientists did using the fruit fly, today we know that the organisms have an internal clock built of a set of cellular proteins whose amount oscillates in periods of 24 hours. These oscillations, which are autonomously maintained, explain how living organisms adapt their biological rhythm so that it is synchronized with the Earth's revolutions.