Modern civilization introduces a wide range of pollutants to the atmosphere through various
activities. Most of the heavy metals are essential elements to living organisms, but their
excess amount are generally harmful to plants and animals; the poison of heavy metals
depends a great deal on their chemical form, concentrations, residence time, etc. [2,6]. Traffic
emissions on roads are the main cause of heavy metal accumulation on the surrounding
environment including vegetation, which might have an ecological effect on them. Elevated
levels of heavy metals in urban and industrialized areas atmosphere are reported in many parts
of the world [10]. Many studies have used trees for monitoring elemental deposition from the
atmosphere. Numerous different bio-indicators are used in monitoring air pollution, such as
mosses, lichens, vascular plants, woody plants, etc. Both the broad-leaved and coniferous tree
barks are used in studies of air pollution [1, 5]. The use of vegetation as passive sampler in
biomonitoring bears the advantage of high spatial and temporal resolution due to the excellent
availability of plants and low sampling costs. Many plant groups, including the evergreen
trees, have been used for monitoring air pollution [9]. The advantages of using higher plants
are that (a) they are inexpensive alternatives to air sampling by filtration; (b) they provide
useful data for the design of deposition monitoring networks; (c) they provide a measure of
integrated exposure over a certain period of time; and (d) they greatly facilitate the analytical
determination of trace elements [4]. In the last few years, biomonitoring, based on the
analysis of trace elements in plants such as tree leaves have been proposed as a solution to the
air pollution monitoring problem. [3] Stated that trees improve the quality of urban life due to
their large leaf areas in relative to the ground on which they stand. Depending on the
structural properties of their surface, they can act as biological absorbers or as filters of
pollutants. In this way trees have ability to remove huge amounts of gaseous pollutants and air
borne particles. In this study, we used the evergreen tree leaves which commonly occur in all
three examination areas. This widespread tree species, namely Ligustrum japonicum, L.
(Oleaceae, Hoffmgg&Link). This plant abundant in urban (industrial and highly traffic) and
rural areas of Azerbaijan, because they are quite tolerant against climatic influences due to
their modesty and adaptability.
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
The aim of this work was to investigate and assess the heavy metal pollution in the
atmosphere of Baku city using Ligustrum japonicum L., tree leaves as a bioindicator. The
result could be used as preliminary baseline data for trace elements concentrations in the
ecosystems for future assessment and monitoring.
Material & Methods
1. Metal analysis by atomic absorption spectrophotometer (AAS)
Three investigation areas have been chosen. The 1
st
one is characterized by high traffic
(Airport), the 2
nd
is located in the industrial zone of Baku (Absheron peninsula) and the 3
rd
zone represents a rural area (botanical garden of Baku State University). Leaf samples from
all sites were collected. After drying, 1 g of a sample was digested in 10 ml of concentrated
HNO
3
was added and the mixture was left at room temperature overnight. Then it was heated
at 160º C for 4 h. The solution was filtered through a Whatman type 589/2 filter. These final
solutions were analyzed for heavy metal concentrations using atomic absorption
spectrophotometer [9].
2. Metal analysis by EDRF After drying and pulverizing. 1 g dry weight each was used for
trace metals analysis by X-ray microscope Horiba- XGT-7000, Energy dispersive X-ray
fluorescence (EDRF).
RESULTS & DISCUSSION
The concentrations of chromium, copper, iron, cadmium and lead in tree leaves of Ligustrum
from each sampling area were determined by atomic absorption spectrophotometer as shown
in Table 1. The X-ray diffraction patterns of the metals of the Ligustrum japonicum from each
sampling area are shown in Figs. 1a, 1b and 1c. The results indicate that all heavy metals are
higher in industrial and heavily traffic area relative to background area, as shown in table 1
and figure 1. The highest concentration values of Cd, Cu, Cr, Fe and Pb were recorded in site
2 (airport) with 0.514±0.13, 45.5±9.99, 3.93±1.11, 250.23±33.36 and 341.3±73.39 ppm
respectively followed by those of site 1 (absheron) with 0.218±0.07, 33.37±8.77, 3.81±0.697,
232.27±54.63 and 257.4±23.70 ppm respectively. These results agree with the results
obtained by X-ray diffraction patterns of the metals, where the peaks of the elements for
Ligustrum japonicum are the highest for those samples collected from site 2( airport) as
shown in fig.1b followed by those of site 1 (absheron) as shown in fig. 1a, while the lowest
peaks of the elements were appeared for those samples collected from site 3 (botanical
garden) as shown in fig. 1c.
Both sites (industry and high traffic) are higher polluted by trace metals in comparison to the
background site (Table 1). The slight difference in concentration between sites 1 (industrial)
and 2 (traffic) is related to industrial activities represented by enriched Cr and Cu
concentrations. Site 2 is characterized by higher Cd, Fe, and Pb contents confirming the
automobile emissions source. The reason for the higher lead values at site 2 might be the
greater use of cars, buses fuelled with leaded gasoline. Industrial and metallurgical processes
as well as the combustion of diesel oil produce the largest emissions of lead. At site 1,
industrial facilities (chemical, pharmaceutical, metallic, petroleum industry) are randomly
distributed in central parts of the region. They represent, together with city traffic and coal
power stations, the sources of various types of pollutants [8].These results give an indication
that the accumulation of trace metals depend on the traffic, industrial activities and
urbanization levels [7].
Table 1: Comparison of Cd, Cu, Cr, Fe and Pb concentration in Ligustrum japonicum leaves
(ppm±sd) at different studied sites.
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
Fig. 1: EDRF analysis of Ligustrum japonicum leaves from (a): Site 1 (absheron), (b): Site 2
(airport) and (c): Site 3 (botanical garden (control)).
CONCLUSION
In conclusion, the exhaust gases of motor vehicles, metalworking industries, and other
anthropogenic sources are the main sources of air pollution in Baku city. Ligustrum
japonicum has been used for the first time as possible and cheap bioindicator of air pollution
in Baku city. Pb, Cd, and Cu are the most pronounced elements detected by the Ligustrum
Site
Cd
Cu
Cr
Fe
Pb
Site 1
(Absheron)
0.218±0.07
33.37±8.77
3.81±0.697 232.27±54.63
257.4±23.70
Site 2 (Airport)
0.514±0.13
45.5±9.99
3.93±1.11
250.23±33.36
341.3±73.39
Site 3 (Botanical
garden)
0.137±0.01
5.47±1.098
1.6290.351
169.77±31.14
98.6±18.91
a
c
a
a
a
a
b
a
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
japonicum leaves. The variation in heavy metals concentrations between the studied sites is
due to heavy traffic capacities and industrialized activities. The leaves investigated seem for
use as effective bioindicator of environmental quality in Baku city, Azerbajjan. This presents
a highly effective method for getting realistic data on the quality of the environment of these
less investigated areas.
REFERENCES
1- Adeniyi AA. Determination of cadmium, copper, iron, lead, manganese, and zinc in water
leaf (Talinum triangularia) in dump sites. Environ. Int. 1996; 6(22):1– 4.
2- Alfani, A., Baldantoni, D., Maisto, G., Bartoli, G. and Virzo de Santo, A. 2000. Temporal
and spatial variation in C, N, S and trace element contents in the leaves of Quercus ilex within
the urban area of Naples. Environ. Pollut. (109): 119–129.
3- Beckett, K. P., Freer-Smith, P. H. and Taylor, G. 1998. Urban woodlands: their role in
reducing the effects of particulate pollution. Environ. Pollut. (99): 347-360.
4- Bosco, M. L. Varrica, D. and Dongarrá, G. 2005. Case study: Inorganic pollutants
associated with particulate matter from an area near a petrochemical plant. Environ. Res. (99):
18–30.
5- Gurbanov E.M., Akhundova A.A. 2009. phutoecological indicators for biological
recultivation for soils polluted with oil in the Absheron peninsula. Вестник
Днепропетровского университета. № 7, т. 17, серия биология, Экология. с.3-8.
6- Маммадова А. О. 2008. Растительные биоиндикаторы и оценка качества
окружающей среды. Изд. Баку, 174 с.
7- Markert, B., Wuenschmann, S., Fraenzle, S., Figueiredo, A.M., Ribeiro, A.P., and Wang,
M., 2011: Bioindication of atmospheric trace metals – with special reference to megacities,
Environmental Pollution, 159, 1991-1995.
8- Mitrovic, M., Pavlovic, P., Lakusic, D., Djurdjevic, L., Stevanovic, B., Kostic, O., Gajic,
G., 2008. The potencial of Festuca rubra and Calamagrostis epigejos for the revegetation of
fly ash deposits. Sci. Total Environ. 407 (1), 338-347.
9- Sawidis, T., Breuste, J., Mitrovic, M., Pavlovic, P., Tsigaridas, K. 2011. Trees as
bioindicator of heavy metal pollution in three European cities. Environ Pollut. 159, 3560-
3570.
10- Scerbo R, Possenti L, Lampugnani L, Ristori T, Barale R, Barghigiani C. Lichen
(Xanthoria parietina) biomonitoring of trace element contamination and air quality assessment
in Livorno province (Tuscany, Italy). Sci Total Environ. 2002; 286(1– 3):27– 40.
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
ХÜLASƏ
YAPON BIRƏOTU (LIQUSTRUM JAPONICUM L.) BITKISINDƏN ISTIFADƏ
ЕDƏRƏK BAKI ŞƏHƏRINDƏ ATMOSFЕRIN MIKROЕLЕMЕNTLƏRLƏ
ÇIRKLƏNMƏ DƏRƏCƏSININ BIOMONITORINQI
Youssеf N.A., Hacıyеva S.R., Gurbanov E.M.
Bakı Dövlət Univеrsitеti
Bakı şəhərində atmosfеrin mikroеlеmеntlərlə (ağır mеtallarla) çirklənmə dərəcəsini
təyin еtmək üçün həmişəyaşıl yapon birəotu (Liqustrum japonicum L. Oleaceae.) bitkisinin
vеqеtativ orqanları analiz еdilmişdir. Bakı şəhərinin çirkli ərazilərilərindən (hava limanı və
Yеni Nеftayırma Zavodu) və nisbətən təmiz ərazidən (AMЕA-nın Mərkəzi Nəbatat Bağı)
toplanmış bitkilərin vеqеtativ orqanlarında Pb, Cd, Cr, Fe və Cu kimi ağır mеtalların
toplanması dinamikası anali еdilmişdir. Analiz nəticəsində məlum olmuşdur ki, Pb və Cd
mikroеlеmеnti avtomobillərin sıх hərəkət еtdiyi ərazilərdə daha çoх toplanmışdır.
Şəhərin sənayе müəssisələrinin ərazisində, əsasən, Cr va Fe kimi ağır mеtallar daha
çoх toplanır.
Açar sözlər: ağır mеtallar, çirklənmiş hava, bioindikatorlar, havanın kеyfiyyəti, sənaye
РЕЗЮМЕ
БИОМОНИТОРИНГ МИКРОЭЛЕМЕНТОВ ЗАГРЯЗНЕННОСТИ ВОЗДУХА В
ГОРОДЕ БАКУ С ИСПОЛЬЗОВАНИЕМ LIGUSTRUM JAPONICUM L.
(OLEACEAE)”
Юссеф Н.А., Гаджиева С.Р., Гурбанов Э.М.
Бакинский Государственный Университет
Загрязненность атмосферы тяжелыми металлами в городе Баку была
исследована путем анализа на вегетативных органах Ligustrum japonicum L. (Oleaceae).
В процессе биомониторинга загрязненности качества воздуха путем анализов и
использования вегететивных оргенов Ligustrum japonicum L. (Oleaceae) был произведен
cбор анализов из двух загрязненных районов (аэропорт и нефтепереработывающий
завод) и одного контрольного (Ботанический сад). Накоплевешся в вегетатильных
органах Pb, Cd, Cr, Fe и Cu в влият на динамику накапления тяжелых металлов.
Движение выбросов тяжелыми металлами явились основным источником загрязнения
атмосферы в городе Баку. Содержание свинца и кадмия оказались самым высоким
в районе с высокой плотностью движения. Промышленная часть города отлигается
высоким содержанием Cu и Fe. Аз-за болшого потека транспорта.
Ключевые слова: тяжелые металлы, загрязнение воздуха, биоиндикаторы,
качество воздуха, индустрия
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
UDC 581.1/1
T
HE INFLUENCE OF SALTS ON PLANT ANTIOXIDATION ACTIVITY
S.M.Abduyeva - Ismayilova
Baku State University
Current data suggests that 25 per cent, or about 53.106 hectares, of land in 25 countries have
been salinized to varying degrees [6]. At the same time, the oceans and seas covering two-
thirds of the Earth’s surface are 3-4 per cent dissolved salts (of which 88.8 per cent are
chlorides). Thus most plants on Earth go through their development cycle in conditions of
high salinity. Conditions of extreme salinity have a negative impact on the development of
cultivated crops, greatly reducing their fertility and sometimes destroying them.
In saline soils plant metabolism weakens and regulation of their oxidizing and antioxidizing
systems is disrupted. Thus, agriculture is harmed significantly by soil salinization.
This problem is frequently observed in the soils of Azerbaijan. Saline soils extend across
almost all the Republic’s lowlands and piedmont plains.
As in all parts of the world and as a result of global climate and other changes, saline soils
expand here day by day. Inhabited arid regions comprise 5.2 thousand ha. (60 per cent) of
Azerbaijan’s land. Most of the arid land is located in the intensively irrigated Kur-Araz
lowlands. Landscape degradation and a tendency towards salinization are inevitable problems
of Azerbaijani nature. Salinization results in a decline of biological fertility in soil and flora
covers, a collapse of biological potential and soil degradation to extreme salinity under
complex influences of natural and anthropogenic factors. Soils under agricultural crops have
been especially subject to salinization. Thus the effects of oxidizing systems in glycophytes
and halophytes in conditions of extreme salinity (NaCl, Na
2
So
4
) have been investigated and
the influence of salts on the chain oxidation process and antioxidation activity in plants
studied.
Materials and methodologies
Plants producing one seed and two seeds were selected as objects of investigation – barleys,
wheat, corns, lathyrus, peas and cotton as well as the halophytes Salicornia herbaceae and
Salicornia europae.
A chemiluminescent method was used to determine antioxidant activity in seeds of the plants
investigated. H
2
O
2
was used to initiate chain oxidation reactions. According to some
investigators [3, 4,5], the influence of H
2
O
2
on proteins and aromatic amino acids, including
unsaturated fatty acids, is observed with slight radiation. To do this 1 gr. of the root was taken
and 5 ml distilled water added to it. It was then mashed and filtered through a filter paper; the
mixture was then poured into a 10ml basin. Later, the total volume of the mixture was made
up to 5ml by adding some water and it was placed into a quantometer. Then 1ml of 0.1%
H
2
O
2
solution (1% for an alcohol fraction) was introduced to the homogenate via a
polyethylene tube. Radiation of sufficient intensity was observed. The radiation induction
period was measured (t
ip
) as a standard of antioxidation activity in the homogenate. It was
determined by experiment (hydroxynon, ascorbic acid + Fe
2+
etc.) that assessment of t
ip
has a
direct relationship to the antioxidation activity of the homogenate.
The results of the investigation and their implications
The results obtained indicate that the activity of antioxidants in plant roots dissolved in water
and alcohol alters according to length of germination. On the 3
rd
and 4
th
days of germination,
antioxidation activity reaches its peak after which it gradually reduces over the following
days. The reason for this is the acceleration of oxidation processes, as well as chain reactions
and an increase in the activity of some oxidases (catalase, peroxidase) from the first days of
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
germination depending on the intensity of growth and respiration. In the first days of
germination and in dark places, in etiolated germinations planted in thermostatic conditions,
in the absence of photosynthetic activity, there is no assimilation. This leads to a gradual
reduction of oxidising substances stocked only in the endosperm of germinated seeds.
Induced (by H
2
O
2
) chemiluminescence in homogenate taken from germinating roots is at
maximum intensity at three and four days of germination. However, the induced
chemiluminescence produces a regular kinetic curve irrespective of germination age. The high
intensity of radiation at three and four days of germination is probably connected to the
accumulation of activators (proteins, amino acids etc.) in seeds.
Activators (proteins, amino acids etc.) isolated from their biological context (in-vitro) in a
molecular state take part in energy migration and they release energy in quanta form when
returning to their former (basic) state, i.e.:
[P]*+AP+[A]*P+A+hv
On the other hand, assessments of radiation intensity and induction periods in liquid solutions
of homogenates taken from various germinating plants always produce higher results than
those in homogenates in alcohol fractions. This is evidently related to a greater solution
(extraction) of activators and antioxidants in liquid fractions.
We attempted to clarify the influence of various coagulated salt solutions (NaCl, Na
2
SO
4
, KCl
etc.) on antioxidation activity in germinating root systems in further experiments (see fig.1.).
Fig.1. Dependence of antioxidation activity on NaCL (a) and Na
2
SO
4
(b) salt concentrations
in germinating barley roots:
t
ip
- assessment of induction period by relative numbers, t=20°C
It is clear that, unlike control plants, the intensity of inductive radiation is greatly increased by
the introduction of H
2
O
2
into a system in a 0.01-0.1 M concentration of Na
2
SO
4
. However,
changes in intensity of radiation and induction period (t
ip
) produce a poor kinetic curve: So,
the radiation present in control plant roots was rather less intense than in the experimental
specimens; measurement of t
ip
produced higher quantities than from the salt specimens.
It is of interest that the kinetic curve of H
2
O
2
and induced chemiluminescence have the same
maximum point in all cases and the process is limited not by the quantity of H
2
O
2
but by the
amount of non-oxidized substances (antioxidants) in the homogenate. This may be proved by
a second introduction of H
2
O
2
(beyond the maximum) into the homogenate. The H
2
O
2
introduced does not result in inductive chemiluminescence as with the first introduction.
Biochemical analysis indicates that the H
2
O
2
in the second introduction does not completely
decompose.
The importance of the highly reduced substratum in this process may be
determined by introducing ascorbic acid into the system. Adding ascorbic acid to the
homogenate increases radiation and the length of the induction period. However, from
experimentation it is clear that ascorbic acid is effective when there are iron ions (Fe
2+
) in the
AMEA Botanika İnstitutunun elmi əsərləri, 2012- ci il, XXXII cild
system. Thus after neutralising the iron in the homogenate by advance application of KCN,
even the highest concentration of ascorbic acid (10
-2
M) does not function as an antioxidant.
We may conclude that ascorbic acid is a very strong reducer, but not a real antioxidant. Our
results coincide totally with those obtained by Y.A.Vladimirov and his colleagues [1]. Thus
researchers have, for many years, wrongly believed ascorbic acid to be a strong antioxidant.
As is known, both iron proteids and iron in non-hemin form are always present in homogenate
taken from germinating plants. Y.A.Vladimirov [2] showed that ascorbic acid in the system
changes a three valence iron (Fe
3+
) into a two valence iron (Fe
2+
). Two valence (reduced) iron
ions take part in chain reactions of oxidation like real antioxidants. Apart from ascorbic acid,
there are many reduced substances in the homogenate: cysteine, glutathione, nicotine acid,
pyroxatexine etc. As a whole, they define the antioxidation activity of a cell.
The antioxidation effect of iron (Fe
2+
) in plant seeds is explained by its reactions with
peroxide-type compounds. Two reactions may be observed between iron ions and peroxide
compounds. However, the reactions produce opposite results. That is to say, iron accelerates
the chain oxidation of lipids and other compounds but causes a division of chain reactions in
reaction with hydro-peroxides formed by induction by hydrogen peroxide. A two valence iron
weakens chain oxidation and acts as an antioxidant by triggering a reaction with free radicals
that lead chain reactions.
ROOH+Fe
2+
RO·+OH·+Fe
3+
In this case, the process has an autocatalytic character. This means the first introduction of
hydrogen peroxide into the system causes an intensification of high amplitude
chemiluminescence. This effect may be observed in liquid and alcohol homogenate fractions
and is limited by the quantity of free hydro-peroxides that have not been divided during the
reaction and two valence iron or other metal ions with changeable valence.
From these experiments, we concluded that under the influence of salts (NaCl, Na
2
SO
4
,
Na
2
CO
3,
KCl, MgCl
2
etc.) the
ratio increases in plant seeds and the t
ip
is greatly reduced.
A reduction of antioxidation activity in seeds may be explained by the increased potential for
oxidation in salty conditions. As is clear, in acutely accelerated conditions of oxidation
processes, reduced antioxidants are also rapidly consumed.
We conducted several further experiments with iso-osmotic solutions of mannitol (osmotic
factor), NaCl and Na
2
SO
4
to substantiate our findings. Solutions of mannitol and salts at
equivalents of 2.27 and 8.42 atmospheres were used.
As may be seen, the intensity of inductive radiation in the solutions equivalent to 8.42
atmospheres is much less than in the control (water) crops. It was determined that the value of
t
ip
in solutions with mannitol at 8.42 atmospheres equivalent is much greater than in the salt
variants. And this is related to the influence of the ions in specific salts.
One finding of our experiments is that the amplitude of inductive chemiluminescence in
liquid fractions of homogenate is always greater than in alcohol fractions. This occurrence is
true for all plant groups (glycophyte and halophyte). It proves that there are more compounds
of reduced and antioxidant nature in liquid fractions than in alcohol fractions.
Thus, it is proved that the acceleration of chain oxidation processes in plant seeds by the
presence of salts severely reduces antioxidation activity.
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