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From root to fruit
Cognizant of the fact that the
roots of the coffee plant contain lev-
els of kahweol similar to the levels
in the beans, researchers intend to
compare the patterns of the gene
activities in these two parts of the
plant and identify which ones are
related to the production of this
compound and also cafestol. Doug-
las Domingues, professor at Unesp,
in Rio Claro (SP), says that to clari-
fy this question the research team
wishes to sequence the transcrip-
tome of two coffee varieties with a
history of distinct enhancement to
try to identify which genes are pres-
ent in different plant tissues.
Aware of the fact that a specific
gene is not active in the leaf, but is
active in the root and other parts of
the plant, by interference it is pos-
sible to test the hypothesis that it
is responsible for the production of
Kahweol and cafestol. Domingues,
who is a member of the interna-
tional consortium for sequencing
the genome of Arabica coffee, at
the moment considers it a priori-
ty to understand the genetic basis
of the coffee plant and the molecu-
lar reasons of the differences in the
concentration of kahweol and caf-
estol in distinct parts of the plants.
The idea is to make use of the
knowledge to increase the resis-
tance, boost genetic enhancement
and produce these compounds in
laboratory, through biotechnology
strategies.
Theyarecontained ingreat concentrations in
the oil of coffee plants and are used by cos-
metic andpharmaceutical industries.
Up to the moment, the studies about
the quantification of these substances in
the coffee plants used to be carried out
in the area of Chemistry and Food Engi-
neering, with their focus on the coffee
bean, where there are variable concentra-
tions from 10% to 15%. As they constitute
an important fraction of the bean, and as
substances of the same chemical class
have an influence on the flavor of mint
and on the aroma of sandalwood, scien-
tists have decided to quantify them in oth-
er parts of the plants.
The researchers measured the con-
centrations of kahweol and cafestol in the
leaves, roots, flowers and fruit of a variety
of Arabica coffee in seven developing stag-
es (from 30 to 240 days after blossoming)
through a method that makes it possible to
separate the chemical compounds.
The analyses indicated that in the flo-
ral buttons there was a higher level of ca-
festol and in the roots there was a bigger
concentration of kahweol, in comparison
to the fruit. At the same time, the concen-
tration of cafestol rose along the devel-
opment process of the fruit, reaching its
peak 120 after the beginning of the blos-
soming process. In the leaves, no cafestol
was detected.
“One of the hypotheses that explains
the presence of these compounds in
some parts of the plant, and their absence
in other parts, as some of their functions
consist in repelling insects or attracting
pollinators, maybe it would bemore inter-
esting using them against organisms that
Specialized newsletter put
the study in the limelight
all over the world
interact with their fruit and roots rather
than chasing the insects that attack the
leaves”, notes Domingues.
The researchers do not know if the un-
equal levels of the compounds in differ-
ent parts of the plants apply to all Arabica
varieties, as they evaluated only one va-
riety. However, knowing which organs of
the plants produce the substances, they
are going to compare the production be-
tween different varieties.
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