Bariloche protein symposium argentine society for biochemistry and molecular biology

145
BIOCELL, 27 (Suppl. I), 2003
PL-P46.
WHEAT LEAF EXTRACELLULAR PROTEINS ARE
OXIDIZED DURING WATER DEFICIT
Lorenzo M
1
, Martinez Tosto AC
2
, Conde RD
1
 and Pinedo ML
1
.
1
Instituto de Investigaciones Biológicas and 
2
Dpto. de Biología,
FCEyN, Universidad Nacional de Mar del Plata. E-mail:
[e-mail]
Reactive oxygen species accumulate in plant tissues in response
to biotic and abiotic stress. Their generation pathway and/or their
location are not completely known. Because the apoplast connects
the environment with the interior of the cell, this is the site where
important defence reactions take place. Previously, in wheat leaf,
we showed that water deficit induces the accumulation of  H
2
O
2
and
 
decreases the extracellular SOD activity. At the same time,
the content of apoplastic proteins is reduced while its oxidative
state increases. Now, we present evidence that O
2
-
  and H
2
O
2
mainly accumulate in vascular tissues, despite that cell types are
different. Thus, the phloem-xylem communication and the
continuum xylem-apoplasm support the increment of oxidized
apoplastic proteins. Western-blott experiments showed specific
oxidation of different apoplastic polypeptides. In addition, proteic
and carbonylation profiles obtained from unstressed intercellular
washing fluids (IWF) incubated for 12 hs at 32
°C were similar to
those displayed by drought stressed plants. The most important
changes observed were the loss of a 70.5 kDa band whose specific
carbonylation was low, and the increment in the oxidative state of
three polypeptides; two of mass higher than 92 kDa and one of 33
kDa.
Supported by UNMDP, CONICET, IFS.
PL-P47.
HELIANTHUS ANNUUS POLLEN PROTEIN AS FLORAL
ORIGIN MARKERS IN HONEY
Baroni MV, Chiabrando GA, Costa MC, Wunderlin DA.
Dpto. Bioq. Clínica, Fac. Cs. Químicas y F.Cs.Exactas Físicas y
Naturales, U. N.C. E-mail: [e-mail]
In this work we report the development of a novel method for the
assessment of floral origin of honey based on the study of pollen
proteins. Proteins are a minor honey component, however, they
are used as internal standard in the evaluation of adulteration by
stable carbon isotope ratio. Honey proteins come from honeybee
and also from pollen. Considering that honeybee proteins should
be common to all types of honey, we decided to verify the usefulness
of pollen proteins as floral origin markers in honey. Previously we
have identified H. annuus pollen proteins that could only be
detected in Sunflower honey. The specific proteins of Sunflower
honey were evaluated by means of Western Blot using polyclonal
antibodies raised in rabbits by immunization of H. annuus pollen
extracts. Herein, we were able to identify a double band of
approximately 33-36 kDa only in those honey containing different
percentages of H. annuus pollen. Afterwards, in order to quantify
the presence of these pollen proteins in honey, we develop a
competitive Enzimoimmunoassay (EIA). For this purpose we
purified the 33-36 kDa proteins by a Mono Q-Sepharose column
using a FPLC system. These purified proteins were used for the
standardization of the EIA procedure. Several honey samples from
different botanical origin were assayed and the results showed a
significant correlation with the standard melissopalynology
procedure. Thus, the analysis of pollen proteins by immunoassays
allows us to identify H. annuus floral origin of honey.
PL-P48.
DETERMINATION OF TRACE ELEMENTS IN POLLEN
OF  Acacia  caven  (Mol.) Molina, USING SPECTROMETRY
OF ATOMIC ABSORPTION
Cristina Barcia, Soledad Cerutti, Luis Martínez, Sonia Barberis
Laboratorio de Bromatología y Area de Química Analítica.
Facultad de Química, Bioquímica y Farmacia. Universidad
Nacional de San Luis. Chacabuco y Pedernera.  (5700) San Luis.
E-mail: [e-mail]
The pollen was used by the man like a food supplement, energy
booster, aids beauty, etc. In this work the toxic and essential metals
of  Acacia caven (Mol). Molina pollen was investigated. Due to
the low levels of concentration of some elements in the samples
was necessary to use a methodology of the higher sensitivity. In
this aspect, the spectrometry of atomic absorption with flame
(AAS) and electrothermic atomization (ETAAS) were the most
suitable analytical methods. Additionally, the Spectrometry of
Optical Emission was used associated to the plasma connected
inductively (ICP-OES) with conventional or ultrasonic
nebulization.  The pollen of Acacia caven (Mol.) Molina contains
calcium, phosphorous, silica, magnesium, iron, copper and
molybdenum as trace amounts. Conversely, three trace elements
that are noticeably absent in food are found in significant quantities
in  Acacia caven pollen. These elements play a role in numerous
biological reactions: chrome, zinc and manganese. Finally, pollen
is very high in nickel and selenium.
PL-P49.
Acacia caven (Mol) Molina POLLEN, AN IMPORTANT
FOOD COMPLEMENT
Cristina Barcia and Sonia Barberis.
Laboratorios de Bromatología.  Facultad de Química, Bioquímica
y Farmacia. Universidad Nacional de San Luis. Chacabuco y
Pedernera. (5700) San Luis. Argentina. E-mail:
[e-mail]
The pollen is a natural nutritional supplement with high content
in protein and it is used in medicine. Contains an amazing amount
of vitamins, essential amino acids, proteins and minerals like
potassium, magnesium, calcium, copper, iron, phosphorous,
manganese, sulfur and chlorine. In this work the analytical
composition of pollen of Acacia caven (Mol.) Molina, was
determined to know its value as a food complement and to
contribute to the denomination of quality in origin of apiculture
products from the Cuyo region (Argentine). The humidity was
determined in a vacuum oven (45 mm Hg) at 65°C, until constant
weight. The ash determination was carried out by burned of the
sample in capsule of Pt at 600°C. The total protein determination
was made by the method of Kjeldhal-Arnold-Cunning. The
carbohydrate determination was carried out by the methods of
Dubois and modified Fehling-Causse-Bonnans. The results were
expressed in percentage of humidity, ashes, total content of
carbohydrates and proteins in dry base of the sample. The results
were agreed with the established data in the Article N° 785 of the
Argentine Alimentary Codex, for the analytical characteristics of
pollen composition as nutritional complement.

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