Rice University Scientists Trace Nanoparticles from Plants to Caterpillars

Rice University scientists traced the uptake and accumulation of quantum dot nanoparticles from water to plant roots, plant leaves and leaf-eating caterpillars.

The study, one of the first to examine how nanoparticles move through human-relevant food chains, found that nanoparticle accumulation in both plants and animals varied significantly depending upon the type of surface coating applied to the particles. The research is available online in the American Chemical Society's journal Environmental Science & Technology.

"With industrial use of nanoparticles on the rise, there are increasing questions about how they move through the environment and whether they may accumulate in high levels in plants and animals that people eat," said study co-author Janet Braam, professor and chair of the Department of BioSciences at Rice.

Braam and colleagues studied the uptake of fluorescent quantum dots by Arabidopsis thaliana, an oft-studied plant species that is a relative of mustard, broccoli and kale. In particular, the team looked at how various surface coatings affected how quantum dots moved from roots to leaves as well as how the particles accumulated in leaves. The team also studied how quantum dots behaved when caterpillars called cabbage loopers (Trichoplusia ni) fed upon plant leaves containing quantum dots.

"The impact of nanoparticle uptake on plants themselves and on the herbivores that feed upon them is an open question," said study first author Yeonjong Koo, a postdoctoral research associate in Braam's lab. "Very little work has been done in this area, especially in terrestrial plants, which are the cornerstone of human food webs."

Some toxins, like mercury and DDT, tend to accumulate in higher concentrations as they move up the food chain from plants to animals. It is unknown whether nanoparticles may also be subject to this process, known as biomagnification.

While there are hundreds of types of nanoparticles in use, Koo chose to study quantum dots, submicroscopic bits of semiconductors that glow brightly under ultraviolet light. The fluorescent particles -- which contained cadmium, selenium, zinc and sulfur -- could easily be measured and imaged in the tests. In addition, the team treated the surface of the quantum dots with three different polymer coatings -- one positively charged, one negatively charged and one neutral.

Source: Eurekalert

Hornworm Caterpillar Shows Unique Defence Mechanism to Ward Off Predators

A caterpillar that has a unique defence mechanism against some of their predators such as wolf spiders, find researchers.

Caterpillar Fungi’s Anti-Inflammatory Properties can be Utilized in Developing Drugs for Number of Conditions

Researchers at University of Nottingham studying the caterpillar fungi, Cordyceps, have found that cordycepin, a drug found in the mushrooms, can be used in developing new cancer drugs.

Caterpillars Hold Key to New Anti-inflammatory Drugs

Caterpillar fungi (Cordyceps) in Tibetan mountains could offer new hope for sufferers of asthma, rheumatoid arthritis, stroke, finds study.

'Probiotics' for Plants Boost Detox Abilities to Withstand Pollution

Using a microbe that occurs naturally in eastern cottonwood trees, scientists have boosted the ability of two other plants - willow and lawn grass - to withstand the withering effects of the nasty industrial pollutant phenanthrene.