| 1989
McCoy Award Recipient
Thomas K. Hodges
Professor of Plant Physiology
Ion transport into plant cells, regenerating whole corn plants from naked (wall-less) cells, and regenerating rice plants from single cells.
The recipient
of the Herbert Newby McCoy
Award for 1989 is Thomas
K. Hodges, Joseph
C. Arthur Distinguished
Professor of Plant Physiology.
Professor Hodges received
a B.S. in Agronomy from
Purdue University in 1958
and a Ph.D. in plant physiology
from the University of
California at Davis in
1962. After receiving that
degree he worked as a Research
Associate in Agronomy at
the University of Illinois
before joining the Horticulture
faculty at the University
of Illinois in 1963. In
1971, Professor Hodges
came to Purdue as a Professor
of Botany and Plant Pathology.
He served as head of the
department from 1977 to
1982. He was named the
Joseph C. Arthur Distinguished
Professor of Plant Physiology
in 1989. Professor Hodges
has received many awards
for his research including
the Charles Albert Shull
Award from the American
Society of Plant Physiologists.
Abstract
of Talk
Crop plants have been improved
systematically through
plant breeding for nearly
a century, and the remarkable
increases in yield have
been dubbed the green revolution
in agriculture. We are
now in the beginning stages
of a gene revolution in
plant biology that will
extend conventional plant
breeding, and it is anticipated
that these new genetic
technologies will provide
the required boost in food
production needed to feed
a growing world population.
The seminar will discuss
the current status of genetic
engineering of plants with
special emphasis on transformation
and regeneration of rice,
maize, and other plants
from single protoplasts
(cells that have had the
outer cell wall removed).
Progress and problems in
identifying genes of importance,
the methods for insertion
of genes into the DNA of
the host plant cell, and
in regrowth of the plant
following insertion of
the gene into an individual
protoplast will be presented.
Research
Professor
Hodges' research in the
last five years has concentrated
on three problem areas:
ion transport into plant
cells, regenerating whole
corn plants from naked
(wall-less) cells, and
regenerating rice plants
from single cells. The
first area is concerned
with a better understanding
of basic processes in plant
nutrition. The other two
are part of the world-wide
effort in biotechnology
to genetically engineer
plants. Professor Hodges
gained prominence in the
1970's for his landmark
studies on plant plasma
membranes and the biochemical
apparatus responsible for
moving ions across the
membrane from the external
environment to the cell's
interior. He was the first
to develop procedures for
purifying plant plasma
membranes; and he showed
that an enzyme, ATPase,
was involved in transporting
ions across the membrane.
In 1982, Hodges embarked
on a new line of research
devoted to developing the
technology necessary for
transforming the genetic
character of plants. He
focused on the major staple
crops of the world that
had been recalcitrant in
adapting to emerging biotechnology.
Regeneration of whole,
reproductive plants from
single naked cells called
protoplasts was the goal
because protoplasts are
capable of receiving new
genetic information. Regeneration
of the cereals (corn, rice,
wheat, barley) into whole
fertile plants was an important
undertaking because this
was the major obstacle
to the genetic engineering
of these plants. He built
a new program in plant
cell and tissue culture
with initial efforts focusing
on corn. The overall approach
was a systematic evaluation
of the conditions and procedures
required for regenerating
plants. At this time there
had been little success
in regenerating corn from
even large pieces of tissue.
Hodges began with large
pieces of somatic (body)
tissue and then proceeded
to smaller tissue pieces
until single cells, and
then protoplasts, were
being investigated. Hodges
recognized that the genotype
as well as the nutrient
environment were critical
variables in determining
whether or not the cells
would grow. Only a few
genotypes were capable
of regeneration, and this
led to the discovery that
when a regenerable inbred
plant was crossed with
a recalcitrant inbred,
the resulting hybrid would
regenerate whole plants
from single cells. This
in turn led to the discovery
that only two or three
genes controlled somatic
embryogenesis and plant
regeneration. Hodges and
his colleagues report the
efficient transformation
of corn protoplasts with
two bacterial genes, simultaneously
one gene makes cells resistant
to an antibiotic, the other
controls synthesis of a
protein that is easy to
measure. Thus, it is now
possible to readily produce
transgenic maize callus.
Because of his tremendous
success with the corn regeneration
project, the Rockefeller
Foundation asked Hodges
in 1985 to develop a project
on regeneration of indica
rice, another major crop
in the world. As with corn,
indica rice regeneration
was found to be under genetic
control. During 1988, Hodges'
group succeeded in regenerating
indica rice plants from
protoplasts. This is especially
important because there
is a great deal of interest
in genetically engineering
indica rice since the indica
varieties are used in most
of the developing countries
of the world. Thus, with
the development of the
techniques for regenerating
these rice cells, genetic
transformation of rice
plants is now possible.
Throughout his career Professor
Hodges has shown the ability
to select important research
problems and pursue them
with systematic and innovative
vigor. He is one of the
best known and most respected
plant physiologists in
the country. Through his
research he has made his
mark not only in the advancement
of basic plant physiology
but now in the adaptation
of plant biotechnology
that will lead to improved
crop plants for a hungry
world. It is for his recent
breakthrough in this universally
respected research that
Purdue University awarded
Professor Hodges the Herbert
Newby McCoy Award in 1989.
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