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Hodnocení subchronického působení atrazinu na raka (Cherax destructor)
HLÁVKOVÁ, Markéta
The evaluation of the sub-chronic exposure to atrazine on crayfish The aim of this study is to evaluate the sub-chronic effect of atrazin on a behaviour, oxidative stress, antioxidant enzyme aktivities and biochemical profile of haemolymph in. These complex data should help to appraise the impact of this substance in the environment. The total test duration was 28 days and was divided into two periods. The first 14 days the crayfish were exposed to two concentrations of atrazine: 6.86 micrograms per liter (ATRenv = environmental concentration in the water in the Czech Republic) and 1.21 milligrams per liter (ATR10% = is coincident to 10% LC50). After the atrazine treatments the depuration 2 weeks phases in water without any chemicals followed. The results indicate that sub-chronic effect of atrazine influenced neither the behaviour of the crayfish nor the level of oxidative stress (measured by TBARS), whereas the changes of superoxiddismutase (SOD) were observed in all tissues (muscles, gills and hepatopancreas). The changes of enzyme activity were observed in catalase (CAT; hepatopancreas and the muscle tissue), glutathione S-transferase (hepatopancreas and the gills tissue), glutathione reductase (GR; the hepatopancreas tissue) and reduced glutathione (the muscle tissue). The influence of ATRenv on the biochemical profile of haemolymph at the following parameters was estimated only for lactate and alkaline, however phosphatase changes made by ATR10% were significant for glucose, ammonia, lactate and alkaline phosphatase measurements. The sub-chronical effect changed the activity of all antioxidant enzymes in hepatopancreas, muscles and the gills tissue of the observed crayfish. The presented results in this study are giving compact information of impact of atrazine on the crayfish and the whole water environment. The suggestion of using the crayfish for tests of toxicity looks like an ideal supplement for triazine herbicide estimations.
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Oxidative damage to cellular components after oxidative stress induction by specific herbicides
Kramná, Barbara ; Wilhelmová, Naďa (advisor) ; Ryšlavá, Helena (referee)
Oxidative stress is caused by overproduction and overaccumulation of ROS (reactive oxygen species). This state is responsible for cellular damage during unfavorable environmental conditions such as drought, low temperatures, salinity. In order to directly study oxidative stress at tobacco plants (Nicotiana tabacum cv. Xanthi) I used specific herbicides, MV (methyl viologen) and 3-AT (3- aminotriazole). There were several markers used for monitoring oxidative damage to cellular components: DNA damage detected by a comet assay, lipid peroxidation, carbonylated proteins and modification of activities of antioxidant enzymes CAT (catalase) and APX (ascorbate peroxidase). Fluorescent microscopy documented changes in a redox state of tobacco cells and a specific signal for peroxisomes was observed after treatment with higher concentrations of MV and 3-AT. Application of both herbicides caused significant DNA damage, while they worked in a different concentrations, MV in µM and 3-AT in mM. Another convincing oxidative stress marker for MV was protein carbonylation. The inhibition of antioxidant enzymes CAT and APX was less significant when compared to the effects of 3-AT. Decreasing membrane stability proved to be an universal oxidative stress marker for both herbicides. On the other hand, lipid...
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Acetyl - CoA carboxylase - evolution and inhibition
Chalupská, Dominika ; Čeřovská, Noemi (advisor) ; Plchová, Helena (referee) ; Vlček, Čestmír (referee)
Abstract
Acetyl-CoA
carboxylase
(ACC)
is
a
key
enzyme
of
fatty
acid
metabolism
with
multiple
isozymes
often
expressed
in
different
eukaryotic
cellular
compartments.
In
agriculture,
inhibitors
of
plastid
ACC
are
used
as
efficient
herbicides
against
grass
weed.
However,
grass
weed
populations
resistant
to
aryloxyphenoxypropionate
(APP)
and
cyclohexanedione
(CHD)
herbicides
represent
a
major
problem
for
sustainable
agriculture.
Using
PCR
and
sequencing
it
was
found
out
that
five
amino
acid
substitutions
in
plastid
ACC
were
correlated
with
herbicide
resistance
of
Avena
sterilis
ssp.
ludoviciana
Durieu
populations
from
the
northern
grain-growing
region
of
Australia:
Trp-1,999-Cys,
Trp-2,027- Cys,
Ile-2,041-Asn,
Asp-2,078-Gly
and
Gly-2,096-Ala.
We
showed,
using
a
yeast
gene- replacement
system,
that
these
single-site
mutations
also
confer
herbicide
resistance
to
wheat
plastid
ACCase:
Asp-2,078-Gly
confers
resistance
to
APPs
and
CHDs,
Trp-2,027-Cys
and
Ile-2,041-Asn
confer
resistance
to
APPs,
and
Trp-1,999-Cys
confers
resistance
only
to
fenoxaprop.
These
mutations
are
very
likely
to
confer
resistance
to
any
grass
weed
species
under
selection
imposed
by
the
extensive
agricultural
use
of
the
herbicides.
...
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Způsoby regulace plevelů v porostech pěstované řepky (Brassica spp.)
TUPÁ, Jiřina
The thesis describes characteristics of rapeseed and its life cycle. Its main objective is to approach the problematics of weeds in the spring formo of rapeseed on the lands of agricultural company AGRO Dolní Bukovsko. Small-plot experiment was founded on cadastral area Bzí near Dolní Bukovsko, in direction to Týn nad Vltavou. The problems in cultivation of cultural plants are caused by weeds, which are negatively affecting the quality of production as well as the economics of cultivation. Evaluation of weeds was carried out by the counting method in the period since March to August 2016. Number of the weed plants which were found on the particular location was regularly registered and evaluated. In the conclustion it is possible to state that long-term regulation of weed occurence has to be undertaken in time, thoroughly and has to be based on complete protection. Complete protection consists of direct and indirect methods of regulation. As one of the many but most effective possibilities it is possible to use herbicide preparations
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Voltammetric Determination of Herbicide Aclonifen Using Mercury Electrodes
Murcková, Klára ; Vyskočil, Vlastimil (advisor) ; Dejmková, Hana (referee)
Presented Diploma Thesis is focused on electroanalytical determination of the herbicide Aclonifen, which belongs to a group of herbicides derived from diphenylether. These herbicides are used due to their effects - inhibition of protoporfyrinogen oxidase synthesis and also inhibition of biosynthesis of carotenoids. Due to its widespread use in agricultural, toxical effects on humans and because of its negative impacts particularly on aquatic ecosystems there is a need for methods capable of determining the presence of Aclonifen in the environment to monitor its ecological impacts. Optimal conditions for the determination of Aclonifen have been investigated in BR buffer - methanolic solution and in BR buffer. Electrochemical behavior of the substance has been studied using direct current voltammetry (DCV), differential pulse voltammetry (DPP) and adsorptive stripping voltammetry (AdSV) on the hanging mercury drop electrode (HMDE) and by using TAST polarography and differential pulse polarography (DPP) on the dropping mercury electrode (DME). UV/VIS spectrophotometric detection was used for comparison to electrochemical detection. Used wavelengths were 308 nm and 388 nm. For electrochemical determination of Aclonifen the above mentioned techniques were used and following results were obtained: DCV...
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Study on stability of triazine based herbicides in water
Petrlíková, Kateřina ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The first aim of this thesis was to find a suitable analytical method for monitoring of stability of four s-triazine herbicides in water samples. Two columns - stationary phases C18, namely products of Waters and Astec were tested in HPLC system. The composition of ACN/H2O mobile phase was changed in the range from 90/10 to 60/40 (v/v). Baseline separation of prometone, propazine and prometryne was achieved on the Astec C18 column with mobile phase ACN/H2O 70/30 (v/v). This separation system was used for the study of stability. The stability of s-triazines was monitored in the period of six weeks. The samples of atrazine, prometone, propazine and prometryne water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples were measured in samples of water - water from Vltava, acidified water from Vltava, water from water tap and acidified water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples.
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Polarographic Determination of the Herbicide Aclonifen
Murcková, Klára ; Vyskočil, Vlastimil (advisor) ; Dejmková, Hana (referee)
This thesis deals with the differential pulse polarographic determination of the herbicide aclonifen and with the TAST polarographic determination of the herbicide aclonifen. A dropping mercury electrode was used as the working electrode. UV/VIS spectrophotometric detection was used for comparison to electrochemical detection, the walenghts used were 308 nm and 388 nm. Optimal pH conditions were determined for determination using TP, DPP and UV/VIS spectrophotometry. The calibration dependences were measured using the found optimal conditions and limits of quantification, and limits of detection were determined. Limit of quantification for aclonifen were found to be 3,4·10-6 mol·L-1 using TP; 2,2·10-7 mol·L-1 using DPP and 4,6·10-6 mol·L-1 using UV/VIS spectrophotometry.
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HPLC separation of chlorophenoxypropionic acid derivatives
Horová, Kateřina ; Kalíková, Květa (advisor) ; Šlechtová, Tereza (referee)
This Bachelor's thesis focuses on the separation of chlorophenoxypropionic acids and their derivatives by a high-performance liquid chromatography. The separations were performed in a reversed phase mode. These compounds are employed as herbicides, i.e. chemical substances to control unwanted plants, to kill weeds. The herbicides studied for the purposes of this thesis were 2-(4-chloro-2-methylphenoxy)propionic acid, 2-(2,4- dichlorophenoxy)propionic acid, 2-(2-chlorophenoxy)propionic acid, 2-(3- chlorophenoxy)propionic acid and 2-(4-chlorophenoxy)propionic acid. The study aimed at finding and optimizing chromatographic conditions for simultaneous separation of all five herbicides mentioned above. The analysis employed two types of columns, that is ZORBAX SB-C8 column and ZORBAX Eclipse XDB-C18 column whose level of polarity differ. As mobile phases, there were used acetonitrile/water, acetonitrile/formic acid, pH 2.1 and methanol/formic acid, pH 2.1 in various volume ratios. ZORBAX SB-C8 column, mobile phase methanol/formic acid (concentration of 0.365 mol/l, pH 2.1) 40/60 (v/v), temperature of 25řC, and flow rate of 1 ml/min delivered the most convenient separation conditions. Given these isocratic conditions, all the herbicides were baseline separated within 80 minutes. Keywords: HPLC,...
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Determination of polar pesticides in waste and surface waters
Borůvková, Tereza ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
This work is focused on the determination of polar pesticides in surface and waste waters. In this study Mecoprop-P, MCPA, Dichlorprop-P, 2,4-D and MCPBA in differently loaded surface waters and communal waters from sewage treatment plants were analyzed. These herbicides are included in the group identified as environmental quality standards. Some of herbicides (2,4-D and MCPA) were selected because their consumption in the Czech Republic exceeds 30 tons a year. Samples were collected prom three rivers near town of Jaroměř (Elbe, Úpa and Metuje Rivers), from one river near the town of Brno (Svratka River) and from inflow and outflow of two sewage treatment plants (WWTP Jaroměř, WWTP Brno – Modřice). Particular rivers were chosen for monitoring due to the probability of occurrence of herbicides, because they flow through agriculturally cultivated areas. Solid phase extraction (SPE) was used for the isolation of target compounds and their concentration. Gas chromatography with tandem mass spectrometry (GC/MS/MS) was used for the determination of target analytes in surface and waste waters. Selected herbicides were detected in all collected samples.
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Analysis of Thick Film Amperometrical Sensors Signal and Its Usage for Measurement and Characterization of Enzymes
Ondruch, Vít ; Kizek, René (referee) ; Masojídek,, Jiří (referee) ; Vrba, Radimír (advisor)
V práci je popsán princip synchronní detekce (SD), který byl uplatněn při měření s biosenzory. Metoda SD umožňuje dosažení výrazně lepšího poměru signálu k šumu, vyššího limitu detekce a celkové zlepšení robustnosti měření. Uplatnění SD při měření s biosenzory umožní zlepšit analýzu jeho odezvy a umožní odstranění nežádoucích interferencí nebo šumů, které mohou být způsobeny například mícháním roztoku, elektromagnetickými vlivy nebo parazitními proudy. SD také umožňuje rozložit získaný signál na odezvu stimulace a na dlouhodobý signál jiného procesu, a dále také identifikovat jevy druhého řádu. Pro identifikaci stimulačního signálu ve výstupním signálu měření byl na základě lineárního statistického modelu vyvinut specializovaný software. SD byla ověřena na modelovém případu výstupního signálu biosenzoru s aplikovaným komplexem fotosystému II (PSII) a jeho odezvě na stimulaci světlem. Odezva PSII se řídí kinetikou prvního řádu a může být také ovlivněna inhibitory. Kinetické konstanty vazby herbicidu na PSII závisí lineárně na koncentraci herbicidu. To umožňuje jejich měření také při nízkých koncentracích herbicidu.
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