Mice, fruit flies, and a small weed called
Arabidopsis
thaliana are all used as model organisms—and have
helped scientists make great strides in understanding
how cells, organisms, and ecosystems function.
Arabidopsis, a ubiquitous weed related to
the mustard plant, is an ideal research
model. Laboratory strains of the species
grow from seed to mature flowering
plants in just six weeks. The plant can
also self-fertilize and produces copious
numbers of seeds, enabling scientists to
quickly detect and study genomic changes
from generation to generation.
Typically, the goal of investigations
using animal models is the betterment
of human health. In plant science, basic
research on model organisms has many
different goals, reflecting the many ways
humans use plants. Plant model species
serve as proofs of concept, illuminating
phenomena in simpler systems that can
be applied to more complex plants and
ecological systems.
Researchers recently identified a gene
in
Arabidopsis that allows it to grow in salty
soil conditions. That insight could help
scientists develop crops that are able to
produce high yields even in salt-affected
soils, which pose a challenge for farmers
in areas throughout the world.
Arabidopsis research, combined with
studies on flax, tomato, barley, rice,
and tobacco, has also helped scientists
to build a detailed diagram of the plant
immune network. This diagram can aid
scientists in developing more disease-resistant
crops, since features of the
Arabidopsis
immune network also operate in
many other species.
How to Make a Plant
Image courtesy of Kent Schnoeker, The Salk Institute.Arabidopsis has one of the smallest genomes
(number of genes) among plants—
a relatively miniscule collection of just
135 million base pairs or so in its genome
of five chromosomes (for comparison,
wheat and corn each have billions of base
pairs in their genomes). Despite its small
size, the Arabidopsis genome contains all
the genes it needs to make roots, grow
leaves, form flowers, produce seeds, and
fight off disease.
The small size of its genome made
Arabidopsis an attractive candidate for
investigating the basic set of genes that
code for all plant functions; in the early
1990s,
Arabidopsis was chosen as the
focus for the first full sequencing of a
plant genome. In late 2000, thanks to
the efforts of thousands of researchers
around the world, the
Arabidopsis reference
genome was completed. It is called
a "reference" genome not only because
it was the first plant genome sequenced,
but also because it has served as a point
of comparison for subsequent efforts to
compare genes among different strains of
Arabidopsis.
But the work is not over. Having the sequence
of one
Arabidopsis individual in hand,
researchers' next task is to match each gene
to its function in the plant—a monumental
undertaking for which the National Science
Foundation formed a project known as
Arabidopsis
2010.
Of course,
Arabidopsis is not the only
model organism for studying plants, just
as mice and fruit flies are not the only
organisms that animal researchers use
in their experiments. Since the Arabidopsis
genome was sequenced in 2000,
researchers have also turned their focus
to the genomes of rice, corn, poplar, tomato,
grape, and other plants.
Translating from Basic to
Aplied Science
Basic research on Arabidopsis and other
plants has made a strong start toward
understanding the fundamental challenge
of how plants work. To most effectively
translate knowledge from basic science
into commercial innovation, however,
there is a need for additional tools and
methods for transferring science from
model systems to crop species, says
the National Research Council report
Achievements of the National
Plant Genome Initiative and New
Horizons in Plant Biology.
Such tools would better enable translation
of basic plant genomics toward sustainable
deliverables in the field.
This web page is based on the National Academies' educational booklet
New Horizons in Plant Sciences.
