College Station, Texas
February 23, 2009
This science may literally be
outside the box: A briefcase-sized kit is carried to a field
where thousands of tons of food are growing. The search is for
microorganisms that could infect and kill the plants, wreaking
havoc on the food supply and market.
If the equipment in the box finds the pathogen, experts can tell
farmers how to prevent the devastation. Quick and accurate are
key.
That’s what scientists plan to do within three years, according
to Dr. Won-Bo Shim,
Texas AgriLife Research plant pathologist. He’s lead
investigator on a $1 million U.S. Department of Agriculture
grant that takes aim at protecting the nation’s food and
agriculture from bacterial, fungal and viral agents on the
homeland security select list.
PADLOC is what they have already named the futuristic kit –
Pathogen Detection Lab-On-a-Chip.
“It’s a portable system,” Shim said. “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 explained, and that time increases the chance for
irreversible damage to the food supply and marketplace.
One of the novel approaches to creating a faster system, Shim
explained, is collaboration between the experts in plant
pathology and his co-investigator Dr. Arum Han, a Texas A&M
University electrical engineer who specializes in nanotechnology
where things are measured in billionths.
The two met almost accidentally at a social for professors. Shim
recalls that as each asked the other about their research
efforts, the notion clicked that one’s skill could supplement
the other to develop a better detection system.
“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,” Shim said. “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, he explained.
Because plants do not have immune systems, breeders are
constantly trying to stay ahead of disease outbreaks by breeding
new varieties – a process that can take years, Shim said. If a
new or foreign plant pathogen is introduced to an area,
susceptible plants are not able to defend themselves. If farmers
knew about the presence of such a disease early enough, the
infected portion of the crop could be eradicated to prevent
disease from spreading to the remaining fields.
“One thing about plant diseases is that there are so many,” Shim
explained. “There are bacteria, fungi and viruses that cause
plant diseases, and the symptoms are also quite diverse. Even
the experts when they see a disease on a plant will scratch
their heads about the cause, especially if it is a newly
introduced microorganism.”
In the 1980s and 90s, plant pathologists relied on visual
inspections to determine diseases, he said. More recently,
technology emerged to allow labs to detect pathogens at the
molecular level with high precision and accuracy. However, this
diagnostic process requires a lab equipped with bulky
instruments.
With Han’s expertise in nanotechnology, the team plans to cram
this “lab” into a “box." And 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, he said, 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 Dr.
Dennis Gross will then do field testing for accuracy.
Next, a team of Texas AgriLife Extension Service agents will
test the user-friendliness of the kit around the state from the
rice fields in the southeast to the ornamental crops in the
northeast and the field crops in the west.
Shim acknowledges that the project is high risk. The team
promises USDA a prototype in three years. But he said the
proposal made for the grant was already so detailed in its
design that the two are confident enough to speak of PADLOC as
if it is already a product.
“It’s a new tool from existing technology,” Shim said. “But we
hope that it can make recommendations in real-time for farmers
so that we would be able to stop a local problem from becoming a
regional or national one.” |
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