Courses:
Cell
and Molecular Biology (214), Genomics
and Proteomics (BIO 426/526), Plant Physiology (455/555)
Research Interests: Plant
Biochemistry and Molecular Biology.
We study several amylase gene families (α-amylase
and
beta-amylase)
from the plant Arabidopsis
thaliana that encode enzymes
capable of acting on starch or related
molecules. Some of these enzymes that are located in plastids have
logical functions. Others are secreted from cells where
they
may act on cell wall carbohydrates or play a role in defense against
pathogens.
The physiological function of most of these genes is unknown. Starting
with the complete sequence of the Arabidopsis genome, we use molecular
and reverse-genetic techniques, in combination with traditional
biochemical
and physiological techniques to try to learn the function of the
enzymes
encoded by these genes. For example we can obtain mutants in
which a
specific
gene has been disrupted and ask whether a certain protein or enzymatic
activity is missing. We can also ask whether starch metabolism or
defense
against pathogens has been altered in any way. We can also create
transgenic plants in which an amylase coding sequence is fused to
GFP. Confocal microscopy can then be used to determine where in
the cell the GFP is located and this will tell us where the amylase was
targeted. What we learn about the
functions of specific genes may eventually allow us to make
genetically
modified crops that produce high value starch for industry or
plants
that are more resistant to certain pathogens.
Selected
Publications: *undergraduate co-author
Doyle, E.A., A.M. Lane*, J.M. Sides*. M.B.
Mudgett, and J.D. Monroe. (2007) An α-amylase (At4g25000) in
Arabidopsis leaves is secreted and induced by biotic and abiotic
stress. Plant Cell and Environment 30: 388–398.
Monroe, J.D., M.L. Garcia-Cazarin, K.A.
Poliquin*, and S.K. Aivano* (2003) Antisense Arabidopsis plants
indicate that apoplastic
α−glucosidase has α−xylosidase activity. Plant Physiology and
Biochemistry 41: 877-885.
Monroe, J.D., C.M. Gough, L.E. Chandler*, C.M.
Loch*, J.E. Ferrante*, and P.W. Wright* (1999) Structure, properties,
and tissue localization of apoplastic α-glucosidase
in crucifers. Plant Physiology, 119: 385-397.
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