Marc A. Cohn
Research interests: Seed Physiology/Weed Science
Mechanisms of seed dormancy
Physiological ecology of seed dormancy
Dormancy of recalcitrant seeds
Seed dormancy, a state of
suspended animation, is advantageous to survival of native
species, but presents serious problems for seed scientists
and producers. In my program, research is focused on the
mechanisms of seed dormancy and the physiological ecology of
seed survival using red rice (Oryza sativa) as a model
system. In collaboration with John Larkin, developmental
geneticist in the Department of Biological Sciences, we have
identified a highly dormant native ecotype of Arabidopsis
thaliana, which will serve as an additional model system.
Work has also begun on dormancy and viability studies of
Spartina alterniflora, a marsh grass whose seeds cannot be
dried. An accurate viability assay has been developed to
pursue aspects of dormancy and recalcitrance.
Questions under current
are the structural features of a chemical that endow it
with dormancy-breaking activity (structure-activity
studies using computational chemistry and computer
modeling of activity)?
the metabolic fate of chemicals used to break dormancy,
and what does this tell us about the dormancy-breaking
dormancy-breaking treatments stimulate germination of
Spartina seeds die when they are dried?
are the best seed processing protocols to maximize the
viability of Spartina seeds after harvest?
the role of protein phosphorylation in signal processing
during seed dormancy maintenance and termination?
are the QTLs that contribute to seed dormancy and
weediness of red rice?
Questions for future study
are the effects of dormancy-breaking chemicals upon
transcription and translation?
How is intermediary metabolism repressed in dormant
seeds, and how do dormancy-breaking chemicals activate
are the natural, environmental cues that stimulate
germination under field conditions?
Can dormancy-breaking treatments be successfully applied
in crop production to reduce the size of the weed
seedbank and reduce overall herbicide inputs?
Miscellaneous Professional Activities
Dr. Cohn received his Ph.D. from Cornell University in 1977
under the guidance of Dr. Ralph Obendorf and has devoted
over 3 decades to seed physiology research. He has served as
Associate Editor of Crop Science and a scientific reviewer
for numerous other journals and grant panels. Dr. Cohn is
the Editor of Seed Science Research, the premier
international journal devoted to basic seed biology. He is a
regular participant at the International Seed Biology and
Plant Dormancy Workshops and is a member of the W-1168
Regional Research Project, Seed Quality Investigations. He
has authored or co-authored more than 50 research papers and
book chapters, as well as an equal number of scientific
abstracts. He has been an invited symposium speaker at the
International Weed Science Congress, Weed Science Society of
America national and regional meetings, as well as
International Seed Science Society meetings and recently
presented the keynote address at the 3rd International Plant
Dormancy Workshop in the Netherlands. He has been an invited
speaker at 40 universities and symposia worldwide. Dr. Cohn
has been a member of the Executive Committee of the American
Society of Plant Physiologists-Southern Division since 1988
and an emeritus member of the parent society's Executive
Committee. He received the ASPP-Southern Distinguished
Service Award in 2001. He was the co-recipient of the LSU
College of Agriculture Distinguished Dissertation Award for
his work with Steve Footitt in 1993. Dr. Cohn is a member of
the Weed Science Society of America, Crop Science Society of
America, American Society of Official Seed Analysts, a life
member of the American Society of Plant Biologists and a
charter member of the International Seed Science Society.
Former students of Dr. Cohn have published their own work in
EMBO Journal, The Plant Cell, and the Proceedings of the
National Academy of Sciences (USA). Dr. Cohn is a life-long
jazz aficionado, has guest lectured in the Jazz History
course at LSU, and was a volunteer jazz broadcaster for more
than a quarter of a century. He is an accomplished French
chef and dedicated servant of his cat.