Researchers hope to significantly shorten the time it takes to identify a new pathogen, regardless of whether it threatens food safety or plant health.


The three-year project, spearheaded by Texas AgriLife plant pathologist Won-Bo Shim, is funded by a $1 million U.S. Department of Agriculture grant.


He and co-investigator Arum Han, a Texas A&M electrical engineer based in College Station, already have a name for their project—PADLOC, or Pathogen Detection Lab-On-a-Chip.


“It’s a portable system,” Shim says. “The idea is to shorten the current detection process to a few hours so that a plan could be set up to minimize impact from such plant diseases.”


Currently, if a new plant disease appears on a farm, it could take days to find, sample, ship to a lab and run tests to verify, Shim says. The longer the time between sampling and confirmation, the greater the chance for irreversible damage to the food supply and marketplace.


“There’s a need for a system that is not only portable but rapid, accurate and ‘dummy proof’ so that someone with no background in the science could use it,” he says. “The technology we need is already available to both plant pathology and engineering. We’re just putting them together.”


But the nature of diseases in plants presents the challenge. Humans and other animals have an immune system, so researchers predict the strains of flu that might be present in a given year and make a vaccine against that, Shim says.


If a new or foreign plant pathogen is introduced to an area, susceptible plants are not able to defend themselves because they don't have immune systems. If farmers knew about the presence of a disease early enough, the infected portion of the crop could be eradicated to prevent disease from spreading to the remaining fields.


In the 1980s and '90s, plant pathologists relied on visual inspections to determine diseases, Shim says. More recently, technology emerged to allow labs to detect pathogens at the molecular level with high precision and accuracy. But they need bulky, expensive instruments.


With Han’s expertise in nanotechnology, the team plans to cram the lab into a box. That means packing the sophisticated measuring devices, reagents, power supply and other features that now take up lab space into a parcel no bigger or heavier than a briefcase.


The kit, Han says, would be “a library to target the plant diseases of national interest.”


The first goal is to make a kit to test in the field. Shim expects that to be accomplished within the first two years of the three-year project. He and plant pathology colleague Dennis Gross will then do field testing for accuracy.

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