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Inqui r y I s sue
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| 2014
t’s a science lesson so fundamental that we teach
it to small children, planting bean seeds in Styrofoam
cups: plants take nutrients from the soil to grow.
It is surprising then, that the complex interchange
between the microorganisms in soils and the cellular
activities of plants’ root systems, what scientists call the
rhizosphere, remains one of science’s great mysteries.
“We want to know how plants and microbes in the soil
talk to each other,” said Marit Nilsen-Hamilton, an Ames
Laboratory scientist and professor in the Roy J. Carver
Department of Biochemistry, Biophysics and Molecular
Biology at Iowa State University. “We know they’re
communicating with each other, but how? Multicellular
communities are vastly more complex than we currently
understand. How do we go about finding out?”
Nilsen-Hamilton said that traditional scientific
methodology, taking samples from the environment back
to the lab for genetic analysis, gives only part of the total
picture of this vital ecological system.
“It can tell us the population of microbes, the various
components of the rhizosphere, and then what the end
products are. It’s basically telling us who’s there and how
many, but who is doing what? How are they doing it? Do we
even know where they’re doing it? We may think we know,
but we really don’t, not for sure.”
The impact of environmental changes on these systems
is another question. Variations in temperature, atmosphere,
and chemical composition of the soil force plant systems
to adapt. Current science, Nilsen-Hamilton says, can only
observe changes in the plant-soil system through analysis of
the end-products.
“Right now the science is like a person who isn’t a
mechanic looking at an operating machine. We can bash it
with our fist and observe that it runs faster or slower; but
unlike a mechanic, we really don’t understand what we did
or why it changed.”
Learning the Language of Cell Life:
AmesLaboratoryScientistsUseGeneticMarkers toDiscover theRhizosphere
B Y L A U R A M I L L S A P S
I
Ames Laboratory scientists George Kraus and Marit Nilsen-Hamilton.
