Digestive ?-amylases from coffee berry borer (Hypothenemus
hampei) and their inhibition by amylase inhibitors from
plants
Copyright
A.J.
Valencia 1 , A.E.P. Bustillo 2 , G.A.O. Ossa 2 & M. J.
Chrispeels 3
1 Depto. de
Química, Univ. de Caldas, Calle 65# 26-10, Manizales-Colombia.
A.A 275; 2 Centro Nal. de Investigaciones de Café, Cenicafé,
A.A 2427, Manizales, Colombia; 3 Dept. of Biology, Univ. of
California-San Diego, La Jolla, CA 92093-0116, USA
Animals depend
on digestive
amylases to
break down and
utilize the
starch in their
food sources,
and insect
larvae that
develop in
starch-containing
seeds require
these digestive
amylases for
their
development and
survival. An
excellent
illustration of
this principle
comes from the
work on the
genetic
engineering of
peas and azuki
beans with the
amylase
inhibitor ?-AI-1
from the common
bean,
Phaseolus
vulgaris.
The adult coffee
berry borer (Hypothenemus
hampei), a
major insect
pest of coffee,
has two major
digestive
?-amylases that
can be separated
by
isoelectrofocusing.
The ?-amylase
activity has a
broad pH optimum
between pH 4.0
and 7.0. Using
pH indicators,
the pH of the
midgut was
determined to be
between pH 4.5
and 5.2. At pH
5.0, the coffee
berry borer
?-amylase
activity is
inhibited
substantially
(80%) by
relatively low
levels of the
amylase
inhibitor
(?AI-1) from the
common bean,
Phaseolus
vulgaris, and
much less so by
the amylase
inhibitor from
Amaranthus. We
used an in-gel
zymogram assay
to demonstrate
that seed
extracts can be
screened to find
suitable
inhibitors of
amylases. The
prospect of
using the genes
that encode
these inhibitors
to make coffee
resistant to the
coffee berry
borer via
genetic
engineering is
discussed.
Index terms:
?-amylase,
amylase
inhibitor,
coffee berry
borer,
Hypothenemus
hampei.
Copyright:
The
copyrights
of this
original
work belong
to the
authors (see
right-most
box in title
table). This
abstract
appeared in
Session 13 –
INSECT
PHISIOLOGY,
NEUROSCIENCES,
IMMUNITY AND
CELL BIOLOGY
Symposium
and Poster
Session,
ABSTRACT
BOOK II –
XXI-International
Congress of
Entomology,
Brazil,
August
20-26, 2000.
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