Root systems in plants are largely hidden to farmers and scientists. But now, European researchers have developed a synthetic polymer that creates 
transparent soil, allowing scientists to identify new ways of preventing food-borne illnesses.
“There are so many things to discover in soil, and we don’t know yet what they are,” says theoretical biologist Lionel Dupuy at the James Hutton Institute in Dundee, Scotland. His and his colleagues’ work has now pierced that veil of secrecy, reports Inside Science.
The researchers tinkered with a synthetic polymer called Nafion, made of 350-to-1,600-micron-wide pellets. Because Nafion is unlike most polymers in that it conducts electricity, it is often used in applications for batteries and fuel cells, reports Discover Magazine. Normally, the polymer particles are opaque and slightly reflective, but the scientists used a specially designed water-based solution to make it transparent in much the same way that light refracts in water.
Researchers already knew that bacteria film can grown on Nafion. The biologists modified the Nafion grains so that they would bind to ions dissolved in a liquid solution, mimicking soil’s natural chemistry.
Plant biologist Laurent Laplaze at the French Institute of Research for Development in Montpellier, who did not take part in this study, says:
This is huge progress. This is a completely new way to look at roots in a more realistic setup than usually used. It is a major technical breakthrough that opens new avenues for plant physiology, plant breeding and the study of plant-microbe interactions.
What the breakthrough provided was an opportunity to study how potentially lethal E. coli bacteria interacted with lettuce roots. E. coli in human intestines normally are beneficial, producing necessary vitamins and fighting harmful bacteria. But some strains can cause severe food poisoning, even death.
The biologists modified a version of E. coli to carry a green fluorescent protein from jellyfish and watched how it interacted with lettuce. They noticed that bacterium form micro-colonies near roots that likely helps them survive outside of intestinal tracts.
“If we understand better the contamination route, then we can develop strategies to limit the transfer of E. coli to the food chain,” Dupuy says. “We don’t really understand how E. coli enters the food chain, particularly for fresh produce.”
Similarly, transparent soils also could be used to study the spread and transmission of other soil-borne infections. “For example, nematode worms are responsible for the transmission of viruses to crops, and transparent soils could be used to study their feeding habits,” Dupuy says.
Source: “See-Through Soil Could Improve Crops,” Inside Science, 9/20/12
Source: “Clear As Mud: Researchers Make Transparent Soil For Plant Research,” Discovery Magazine, 9/25/12
Image by Inside Science, used with permission.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.
