Shaping the Future of
UK College of Agriculture has hired four plant scientists through
funds generated from the Kentucky General Assemblys Research
Challenge Trust Fund (RCTF). Popularly known as Bucks for
Brains, this program matches donations to the university
The scientists research illustrates both the breadth and
depth of studies that have the potential to improve farming and
the environment. The studies range from very basic research at
the molecular level to more applied research where the results
can be put to practical use almost immediately. Their research
is described here.
Wetlands, Cleaner Water
bogs, and swamps are sometimes called the kidneys of the
landscape, because they remove pesticides, nutrients, and
metals contained in water through a slew of physical and chemical
processes. In so doing, these wetlands cleanse the water entering
into lakes and streams. On top of that, wetlands support a wide
range of wildlife, from frogs to birds and other mammals.
Kentucky, 80 percent of the states natural wetlands have
been lost due mostly to farming and coal mining. But Kentucky
is one of the few states that is actually increasing its amount
of wetland acreage, in large part because of federal rules that
require developers who disturb natural wetlands to replace them
with man-made wetlands on at least an acre-for-acre, and sometimes
But are these new, constructed wetlands the real deal? How well
do they purify water compared with the natural ones that are centuries
old? Those are some questions that soil biochemist Elisa DAngelo
is asking. Her research compares the nutrient storage and transforming
capacities of man-made wetlands (called mitigated wetlands) with
the real thing, natural wetland areas next to rivers that have
been around for eons of time.
Specifically, shes monitoring several key biochemical processes
in wetland soils responsible for water quality improvement at
more than a dozen man-made and natural wetlands in western Kentucky.
The man-made wetlands range in age from one year to more than
Wetland soils, compared with upland and aquatic soils, she explained,
are unique in that they harbor microorganisms that biochemically
purify water that flows through them. They are truly Mother Natures
water treatment plant.
The science of creating man-made wetlands is in still in
its infancy. And without accurate knowledge, we can only guess
at where and how man-made ones need to be built, she said.
That guesswork can lead to costly or inefficient use of constructed
If the constructed wetland works only half as well as a
natural one, we would need to use twice as much land to achieve
the same results; if it works as well as or better than naturally
occurring wetlands, then a two-for-one rule that is sometimes
applied is highly expensive, she said.
DAngelos approach is unique: its a biogeochemical
approach, which implies measuring physical, chemical, and biological
processes inside the wetland, rather than measuring only inputs
and outputs, which has been the standard technique so far.
We know the big-picture processes responsible for water
purification in wetlands such as deposition of nutrient-enriched
sediments and plant detritus, the decomposition of organic matter
by aerobic and anaerobic bacteria, nitrification and denitrification,
sorption and precipitation reactions. How efficient these processes
are depends on environmental conditions and microbial communities
in the wetlands, which are likely different in man-made sites
compared with pristine ones, she said.
and phosphorus are the main elements of concern in her research,
as they are largely responsible for the algal blooms and aquatic
plant-clogged waterways. Besides causing off-flavors in drinking
water and being a nuisance to boaters and fisherman, aerobic decomposition
of dead algal cells and plants in lakes and streams leads to lower
levels of dissolved oxygen and fish kills.
A well-known example is the Dead Zone a tract
in the Gulf of Mexico the size of New Jersey in which all
manner of aquatic life perishes for several months each year as
a result of low dissolved oxygen caused by algal decay and overabundance
of nutrients emanating from the Mississippi River. Losses of wetland
areas adjacent to the Mississippi have been linked to this phenomenon.
We expect that there will be significant changes in rates
at which water impurities are processed and also in microbial
communities that process them between the mitigated and pristine
wetlands. We hope our results will provide scientists and engineers
the necessary tools to assess whether an engineered ecosystem
is following the correct track, so that actions can be taken to
correct a failing system, she said.
Plants from Viruses
Nagy speaks with a decided accent. And he should. The plant
virologist is from Hungary. He arrived at the UK College of Agriculture
two years ago via the University of Massachusetts, where he completed
Nagys work involves plant viruses and even with an accent,
he can mesmerize you with the details of their lives and their
In fact, viral mistakes are Nagys stock in trade as a plant
The idea goes something like this. Viruses invade their host
for Nagy this is a plant, but animals can be hosts, too, as we
all know. The virus sets up housekeeping and starts copying itself
at a frenetic pace.
think about when you have a virus, such as a cold. When the virus
has made enough copies of itself, you start to feel sick, and
as the number of copies gets larger and larger, you feel worse
and worse. But because the virus is making copies of itself so
fast, it makes mistakes not just little meaningless ones
but serious mistakes that can lead to its own self-destruction.
Those self-destructing mistakes and how they can be promoted
and used to protect plants from viral harm are the subject
of Nagys research.
the specifics. Viruses, which are much too small to be seen without
the use of special microscopes, come in a variety of sizes and
shapes and structures. (Several hundred thousand of them could
fit into the period at the end of this sentence.) Further compounding
their mystique is the fact that some copy themselves using DNA,
like animals, and some replicate using only RNA, because thats
all they contain.
viruses are the most abundant types; those that cause the human
cold, encephalitis, and flu are all examples of RNA viruses. RNA
viruses make many more mistakes in replicating than do the DNA
types. Thats why it seems that each year the world is warned
of a new flu or new cold, with names such as Spanish flu, Hong
Kong flu, Swine flu and the like they are mutations of earlier
research is focused on how to cause the RNA-viruses to make mistakes
more often. Without help they make mistakes in replication one
out of 10 times, which means a great number of mistakes considering
they can make millions of copies of themselves in a day.
specifically, it is during the copying that bits and pieces of
the genetic code are written backward or with letters left
out so to speak. These mistakes sometimes become parasites
that attack the virus (which also is a parasite) from which they
came. Now, thats gratitude for you.
is researching ways to understand this process and force the viruses
to make mistakes happen more quickly and more often so that molecular
parasites developed from the virus can out-compete (and minimize
or eliminate) the parent virus before it has killed or debilitated
his laboratory, Nagy has been able to cause mistakes in a virus
that is widely found and destructive in wild tobacco
and tomato. These mistakes compete with the original
virus and weaken its ability to destroy the plant, but it doesnt
live very well even with the virus having been weakened.
has genetically modified these mistake viruses, so
that they can out-compete the parent virus so well that they can
eliminate the parent virus from the plant. And because the modified
mistake virus causes no harm to the plant, the plant
does the new, molecular parasite work? Nagy rubs a bit of the
new, genetically modified mistakevirus on a leaf of
wild tobacco, previously infected with the parent
virus. The new parasite out-competes its parent virus and the
is enthusiastic that his technique can be refined and used to
help farmers protect their crops. Conceivably, farmers could
spray crops with genetically modified mistake viruses
to protect their crops. But more likely, skilled plant breeders
will be able to breed into seed the mistake virus
so that the plant will be protected from the time it germinates,
How does the scientist with so much enthusiasm stop thinking about
his research when he goes home? He doesnt.
I tell my 9-year-old about the value and power of science
and how we can protect plants, animals, and humans, Nagy
That Tell Genes What to Do
about what you ate yesterday. Try to name something you ate that
doesnt have any connection with seeds, either directly or
indirectly. You probably cant.
why plant scientist Sharyn Perrys very basic research
has such importance. Her goal is to find out how plant cells know
how to develop into seed tissue that eventually grows into a new
plant or is eaten for food for humans or other animals, some of
which in turn are consumed by people.
Its really molecular biology with an agronomic purpose.
Shes investigating things that you cant see with a
naked eye that are both complex and simple at the same time. Theyre
complex because she cant see whats really happening
at the molecular level; theyre simple because the process
is likely straightforward enough once she understands it.
Her goal is to understand better something called AGL-15, which
is shorthand for Agamous-like 15, a protein that is involved in
gene expression. AGL-15 sets in motion what scientists call transcription
machinery enzymes that glide up or down the DNA and turn
genes on or off. If the gene is turned on, it is expressed and
the plant develops a certain way; if it is turned off, its
not expressed and the plant develops quite differently. As such,
then, AGL-15 is necessary for switching on or switching off genes
that eventually lead cells to develop into seed.
can a researcher investigate things that she cant really
see? Thats complicated.
Perry first mechanically pulverizes plant embryos of Arabidopsis,
a weed of the mustard family.
The resulting dust is treated with an antibody developed from
rabbits, which binds to AGL-15, which is bound to the DNA. Tiny
beads that are so small that youd have to have many of them
to be able to detect them are added to the mixture, where they
bind to the antibody. Then, after the mixture is whirled a bit
in the centrifuge, the beads now with the antibody, DNA,
and protein together clinging to them are removed and heated.
Heating separates the DNA pieces from the protein. The cleaned
DNA is replicated (so that she has more of it to work with) and
then compared with the known Arabidopsis genome map to see exactly
where the AGL-15 was positioned. (Even though Arabidopsis is a
weed, researchers have determined its entire 5-chromosome genome
map.) By comparing the DNA fragments with the known genome map,
she will be able to ascertain just which genes are turned on or
turned off by AGL-15.
her research has isolated genes that have passed many of the tests
to show that they are regulated by AGL-15, but many more tests
are needed to fully understand how the regulated genes function
in seed development.
Finding out what genes AGL-15 regulates will help us understand
how this particular protein functions during plant development.
Because this protein is a member of a protein family believed
to be involved in critical development decisions of fungi and
animals, as well as plants, I am hopeful this research can help
our understanding of the entire cell differentiation process in
many organisms, Perry said.
Maps, More Precise Farming
scientist Tom Mueller is refining techniques that Cro-Magnon
hunters developed about 35,000 years ago: making maps of productivity.
The early hunters used bits of charcoal to draw on cave walls
pictures of animals they hunted along with track lines and tallies
to show the animals migration routes, presumably to help
the hunters become more successful on their next hunt.
But instead of a lump of charcoal, Mueller uses high technology
equipment, some of it situated several miles in the sky, to make
productivity maps. And instead of noting the migration of wild
animals, Muellers focus is yield potential in fields. Mueller
is using cutting-edge technology to improve the precision of farming.
Somebody once said that precision farming allows farmers
to do the right thing, at the right time, in the right way. Mapping
where a fields fertility is good and where it could benefit
from fertilizer helps farmers improve yields while cutting costs,
And while farmers have been using the technologies of precision
agriculture for a few years now, it could be even more precise.
And thats exactly what Muellers research is doing.
He is using space-age machines and concepts, including global
positioning systems (that locate exactly where the tractor is
in the field), yield monitors (that record how much grain is harvested
within a few square feet of the field), and geographic information
systems (that record and map key field factors), as well as soil
sensors and remote sensing devices to improve the information
farmers have from which to make decisions.
Some of Muellers work has shown that the electrical conductivity
of soils is related to topsoil depth and depth of fragipan (a
hard layer in soils that reduces root growth). Measuring how well
a fields soil conducts electricity gives some indication
of yield potential. And registering a fields conductivity
with a global positioning system (GPS) allows farmers to make
precise decisions about particular parts of a field. However,
electric conductivity varies over time, depending on environmental
conditions such as soil moisture.
understand better whether this variability is important, Mueller
checked soil conductivity within fields several times over the
course of a year. Using a special device that sent an electrical
charge from one coulter (which looks a great deal like a circular
knife you use to cut pizza) to another coulter, both of which
were slicing through the soil, he measured soil conductivity at
the same points at different times during the summer. The amount
of electricity that the second coulter picked up was compared
with the amount sent to determine the soils conductivity.
Although the electrical conductivity values at every point changed
throughout the growing season, the pattern within the field remained
relatively constant, suggesting that farmers using electrical
conductivity as part of their precision agriculture strategy may
want to take into consideration that values at any point are contingent
upon soil moisture and other factors that vary throughout the