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available from
The National Technical Information Service
(NTIS)
Order from NTIS by: phone at 1-800-553-NTIS (U.S. customers);
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Order
No. |
Title |
Abstract |
NTIS/02390181
82p
|
2002
- Soil Processes Impacting Groundwater Quality in the
North Carolina Piedmont: Contamination by Organic Agrochemicals.
Authors:
Vasudevan D, Cooper EM
Duke
Univ. Wetland Center, Durham, NC. Nicholas School of the
Environment.
Sponsored by North Carolina Water Resources Research Inst.,
Raleigh.
|
This
research explores the potential for sorption, desorption,
and transformation of three herbicides, 2,4-D, norflurazon,
and quinmerac, in two representative iron-oxide rich soil
profiles of the North Carolina Piedmont, Appling and Georgeville
series. Following extensive characterization of soils, we
used batch and continuous flow stirred tank reactors (CFSTRs)
to examine the above mentioned processes as a function of
soil sample depth, composition, and physical-chemical properties
and herbicide molecular structure and physical-chemical
properties. Loss of the two ionogenic herbicides, 2,4-D
and quinmerac, from soil solution was primarily due to sorption;
the loss was strongly correlated with soil surface area,
total Al and Fe, and crystalline iron oxide and amorphous
aluminum oxide content. Loss of the
neutral herbicide, norflurazon, however, was only correlated
to total soil carbon. Under the experimental condition
of our CFSTR, we observed that deionized water could either
completely or partially desorb the sorbed herbicide and
theat desorption was initially more rapid than sorption.
We hypothesize that the mass of 2,4-D and qunmerac involved
in reversibile sorption is associated with soil iron oxides
via favorable electrostatic interactions and/or weak surface
complexation, whiled desorbing norflurazon fraction is associated
with soil organic matter. The irreversibly retained herbicide
mass is most likely involved in strong surface complexation
or is entrapped within the soil matrix. Our results suggest
that along with traditionally used soil properties, total
Fe and Al and/or crystalline iron oxide content may be important
in determining the fate and transport of ionogenic herbicides
in NC ultisols. |
NTIS/PB96-197660
RED
Available online (201 pages) |
1996
- Reregistration Eligibility Decision (RED): Norflurazon.
(Includes RED Facts: Norflurazon Fact Sheet).
Environmental
Protection Agency, Washington, DC. Office of Prevention,
Pesticides and Toxic Substances. |
The
document presents the Agency's decision regarding the reregistration
eligibility of the registered uses of nonflurazon. Section
I is the introduction. Section II describes norflurazon,
its uses, data requirements and regulatory history. Section
III discusses the human health and environmental assessment
based on the data available to the Agency. Section IV presents
the reregistration decision for norflurazon. Section V discusses
the reregistration requirements for norflurazon. Finally,
Section VI is the Appendices which support this Reregistration
Eligibility Decision. For Fact Sheet only, see PB96-197652. |
NTIS/PB96-197652
16p
Available
online |
1996
- RED Facts: Norflurazon.
Environmental
Protection Agency, Washington, DC. Office of Prevention,
Pesticides and Toxic Substances.
|
The
fact sheet summarizes the information in the RED document
for reregistration case 0229, norflurazon. Norfluorazon
is a selective preemergent herbicide used to control germinating
annual grasses and broadleaf weeds in fruits, vegetables,
nuts, cotton, peanuts, soybeans, and various nonagricultural
and industrial areas. Fact sheet. See also PB87-118477 and
PB96-197660. |
NTIS/TIB/A93-02353
45p |
1990
- Neue Wege zur weiterfuehrenden Beurteilung der Langzeitdynamik
in sandigen Grundwasserleitern bei Uferfiltration und
kuenstlicher Grundwasseranreicherung. Verlaengerung Teilvorhaben
1. (New mode to characterize the
long time changement of groundwater quality in sandy aquifers
depending on embankment
Authors:
Muehlhausen D
Deutscher
Verein des Gas- und Wasserfaches e.V., Eschborn (Germany,
F.R.).
Bundesgesundheitsamt (BGA), Langen (Germany). Inst. fuer
Wasser-, Boden- und Lufthygiene.
Supporting Agency: Umweltbundesamt, Berlin (Germany). |
In
the course of the above research project, traces of plant
protectives were found in the Rhine and in embankment filtrate.
These agents deserved further investigation. Triazineherbizides
including some metabolites of atrazine, metolachlor, metazachlor,
norflurazon, and chloridazon
are less appropriate as tracers for embankment filtrate
influx due to their insufficient concentrations. The influence
of embankment filtration can be well documented with mecoprop,
bentazone, dikegulac, and di-O-isopropyliden-L-sorbofuranose.
Further possible tracers that can be used are di- and tetrachlorophthalic
acid. Due to the above mentioned substances and due to the
course of concentration of the AOX it can be demonstrated
that the influx of embankment filtrate has reached the wells
by now. From the existing data it cannot be definitely concluded,
if the drinking water wells contain portions of embankment
filtrate too. (orig.). (RN8908(91-056/3).) (Copyright (c)
1993 by FIZ. Citation no. 93:002353.) In German |
NTIS/PB86-135159
106p |
1984
- Guidance for the Reregistration of Pesticide Products
Containing Norflurazon as the Active Ingredient.
Environmental
Protection Agency, Washington, DC. Office of Pesticides
and Toxic Substances.
|
The
document contains information regarding reregistration of
pesticide products containing the subject active ingredient.
The document includes how to register under a registration
standard, regulatory position and rationale, and summaries
of data requirements and data gaps. Also included is a bibliography
containing citations of all studies reviewed by EPA in arriving
at the positions and conclusions contained in the standard. |
NTIS/PB87-118477
9p |
1984
- Pesticide Fact Sheet Number 60: Norflurazon.
Environmental
Protection Agency, Washington, DC. Office of Pesticide
Programs. |
The
document contains up-to-date chemical information, including
a summary of the Agency's regulatory position and rationale,
on a specific pesticide or group of pesticides. A Fact Sheet
is issued after one of the following actions has occurred.
(1) Issuance or reissuance of a registration standard, (2)
Issuance of each special review document, (3) Registration
of a significantly changed use pattern, (4) Registration
of a new chemical, or (5) An immediate need for information
to resolve controversial issues relating to a specific chemical
or use pattern. |
Plant
Science Volume 165, Issue 2 , August
2003, Pages 373-381
Transgenic
rice plants expressing human CYP1A1 exude herbicide
metabolites from their roots
Hiroyuki
Kawahigashi (a), Sakiko Hirose (a), Hideo Ohkawa (b)
and Yasunobu Ohkawa (a)
(a)
Plant Biotechnology Department, National Institute of
Agrobiological Sciences, 2-1-2, Kannondai, Tsukuba,
Ibaraki 305-8602, Japan
(b) Research Center for Environmental Genomics, Kobe
University, Rokkodaicho 1-1, Nada, Kobe 657-8501, Japan
We
introduced a human cytochrome P450 CYP1A1 gene into
rice plants (Oryza
sativa cv. Nipponbare) to confer herbicide tolerance.
In germination tests, the R1 seeds showed tolerance
to various herbicides with different modes of action,
including quizalofop-ethyl (0.2 M), norflurazon
(0.5 M), mefenacet (2.5 M), and chlortoluron
(100 M). We used 14C-labeled atrazine, chlortoluron,
and norflurazon to confirm the metabolism of herbicides
by the action of the introduced CYP1A1. Although both
CYP1A1 plants and nontransgenic control plants metabolized
these herbicides into the same set of chemical compounds,
the herbicides were metabolized more rapidly in the
CYP1A1 plants. We were surprised to find that
the levels of the intermediate metabolites were higher
in the culture medium of the CYP1A1 plants than in the
plants themselves, because it is commonly accepted that
herbicides are taken up, metabolized, and stored in
plants. The metabolites of herbicides seemed to be exuded
into the medium from the roots of the CYP1A1 plants.
The introduced P450 enhanced the metabolism of the herbicides
in plants. Therefore, the CYP1A1 plants became more
tolerant to various herbicides than the control plants.
|
Agriculture,
Ecosystems & Environment Volume 78, Issue 3 , May
2000, Pages 283-289
Short communication
Dissipation of herbicides in
soil and grapes in a South Australian vineyard
Guang-Guo Ying and Brian
Williams,
Department
of Environmental Science and Management, The University
of Adelaide, Roseworthy Campus, Roseworthy, SA 5371,
Australia
The persistence of herbicides applied in vineyards has
become a concern in recent years due to their wide use.
Investigations into the fate of herbicides in a vineyard
in the Barossa Valley, South Australia, have been directed
towards the dissipation of herbicides in soil and on
grapes. Concentrations of the herbicides, norflurazon,
oxadiazon, and oxyfluorfen in soil were monitored following
their application in the vineyard. With the exception
of oxyfluorfen, dissipation of these herbicides in the
vineyard soil was characterised by fast initial loss
followed by slow degradation. For oxyfluorfen the dissipation
was slow throughout the period of the study. The half-life
for norflurazon in surface soils varied from 50 days
in 1996 to 22 days in 1997 while that for trifluralin
was 27 days in 1996 and 30 days in 1997. Oxyfluorfen
had a very low dissipation rate with a half-life of
119 days. Oxadiazon had a relatively short half-life
of 14 days. Dissipation of the herbicide residues on
grapes in the Roseworthy campus vineyard showed that
trifluralin and oxyfluorfen were not detected 4 days
after treatment, while norflurazon
and oxadiazon remained on grapes 1 month after treatment.
This study showed that the dissipation of herbicides
in soil and on grapes was dependent on the physicochemical
properties of the herbicides and environmental conditions.
The use of these relatively persistent herbicides in
vineyards has the potential to harm vines and to contaminate
grapes and the wine made from them.
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10227191&dopt=Abstract
J
Environ Sci Health B. 1999
May;34(3):397-411.
Herbicide
residues in grapes and wine.
Ying
GG, Williams B.
Department of Environmental Science and Management,
University of Adelaide, Australia.
The
persistence of several common herbicides from grapes
to wine has been studied. Shiraz, Tarrango and Doradillo
grapes were separately sprayed with either norflurazon,
oxyfluorfen, oxadiazon or trifluralin-persistent herbicides
commonly used for weed control in vineyards. The dissipation
of the herbicides from the grapes was followed for 28
days following treatment. Results
showed that norflurazon was the most persist herbicide
although there were detectable residues of all
the herbicides on both red and white grapes at the end
of the study period. The penetration
of herbicides into the flesh of the grapes was found
to be significantly greater for white grapes than for
red grapes. Small-lot winemaking experiments
showed that norflurazon persisted at levels close to
the initial concentration through vinification and into
the finished wine. The other herbicides degraded, essentially
via first-order kinetics, within the period of "first
fermentation" and had largely disappeared after 28 days.
The use of charcoal together with filter pads, or with
diatomaceous earth was shown to be very effective in
removing herbicide residues from the wine. A
5% charcoal filter removed more than 96% of the norflurazon
persisting in the treated wine.
PMID: 10227191 [PubMed - indexed for MEDLINE]
|
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9175497&dopt=Abstract
Arch Environ
Contam Toxicol. 1997 May;32(4):337-45.
Pesticides
in canals of South Florida.
Miles CJ,
Pfeuffer RJ. South Florida Water Management District, 3301 Gun
Club Road, West Palm Beach, Florida 33406, USA.
Atrazine,
ametryn, bromacil, simazine and norflurazon were the most frequently
detected pesticides in surface water samples
and DDE, DDD and ametryn were the most frequently detected pesticides
in sediment samples collected over the period November 1991
to June 1995 in a monitoring network that includes 27 stations
in south Florida canals. The 744 pesticide detections during
this time period represent about 2% of the total number of analytical
determinations. Many of the most frequently detected compounds
were used in large amounts in the monitoring area based on pesticide
usage estimates included in this study. Spatial trends in pesticide
detections followed use patterns. The maximum atrazine detections
occurred in winter to late spring and were associated with usage
on turfgrass and agricultural products. Endosulfan residues
above the Florida water quality criterion were occasionally
observed in surface water in the Homestead area and most of
the exceedences occurred in confined waters. Methods with lower
MDLs have recently been developed and should increase the number
of detections in future sampling. Pesticides which bind strongly
to soil, pesticides that are highly persistent and those used
in large amounts were some of the more frequently found pesticides
in sediments.
PMID: 9175497
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12685039&dopt=Abstract
J Plant
Physiol. 2003 Jan;160(1):3-8.
Effect
of photooxidative destruction of chloroplasts on the expression
of nuclear genes for C4 photosynthesis and
for chloroplast biogenesis in maize.
Tamada
Y, Imanari E, Kurotani K, Nakai M, Andreo CS, Izui K.
Graduate
School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502,
Japan.
Norflurazon,
an inhibitor of carotenoid synthesis, is known to cause photooxidative
destruction of chloroplasts. Expression of many nuclear genes
for chloroplast-destined proteins is suppressed in the photobleached
seedings due to impairment of signaling from chloroplasts to
nuclei. Here the effect of norflurazon-treatment on the expression
of genes for C4 photosynthesis was investigated. Unlike the
genes of Cab and RbcS, the levels of mRNA for pyruvate Pi dikinase
and NADP-malic enzyme were not markedly reduced. However, their
protein levels were more significantly reduced suggesting a
control by chloroplast exerted at the translational step. From
their molecular sizes these proteins seemed to have been correctly
processed and hence localized in the rudimental chloroplasts.
In support of this, 9 kinds of proteins for chloroplast biogenesis
such as Toc family and Hsp 70 proteins were not suppressed,
suggesting that protein import machinery and processing are
still functional in the cells harboring rudimental chloroplasts.
Diurnal changes of the levels of transcripts for photosynthetic
genes persisted in the norflurazon-treated seedlings indicating
non-involvement of chloroplast in this light control.
PMID:
12685039 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12594922&dopt=Abstract
Philos Trans
R Soc Lond B Biol Sci. 2003 Jan
29;358(1429):135-44; discussion 144-5.
Coordination
of plastid and nuclear gene expression.
Gray
JC, Sullivan JA, Wang JH, Jerome CA, MacLean D.
Department
of Plant Sciences, University of Cambridge, Downing Street,
Cambridge CB2 3EA, UK. jcg2@mole.bio.cam.ac.uk
The coordinated
expression of genes distributed between the nuclear and plastid
genomes is essential for the assembly of functional chloroplasts.
Although the nucleus has a pre-eminent role in controlling chloroplast
biogenesis, there is considerable evidence that the expression
of nuclear genes encoding photosynthesis-related proteins is
regulated by signals from plastids. Perturbation of several
plastid-located processes, by inhibitors or in mutants, leads
to decreased transcription of a set of nuclear photosynthesis-related
genes. Characterization of arabidopsis gun (genomes uncoupled)
mutants, which express nuclear genes in the presence of norflurazon
or lincomycin, has provided evidence for two separate signalling
pathways, one involving tetrapyrrole biosynthesis intermediates
and the other requiring plastid protein synthesis. In addition,
perturbation of photosynthetic electron transfer produces at
least two different redox signals, as part of the acclimation
to altered light conditions. The recognition of multiple plastid
signals requires a reconsideration of the mechanisms of regulation
of transcription of nuclear genes encoding photosynthesis-related
proteins.
Publication
Types: Review; Review, Tutorial
PMID: 12594922
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12387404&dopt=Abstract
Environ
Sci Technol. 2002 Oct 15;36(20):4319-25.
Effect
of two organic amendments on norflurazon retention and release
by soils of different characteristics.
Morillo
E, Maqueda C, Reinoso R, Undabeytia T.
Instituto
de Recursos Naturales y Agrobiologia de Sevilla (CSIC), Seville,
Spain. morillo@irnase.csic.es
The influence
of two organic amendments on norflurazon sorption-desorption
processes in four soils with very different physicochemical
characteristics was studied in laboratory experiments to evaluate
the potential leaching of this pesticide through organic fertilized
soils. Sorption-desorption experiments were performed on original
soils and on a mixture of these soils with urban waste compost
(SUW) and a commercial amendment from olive-mill wastes (OW),
at a rate of 6.25% (w/w). These mixtures were used immediately
after preparation and after aging for 2 months. Norflurazon
was analyzed by using a HPLC method. Norflurazon retention in
original soils was related not only to the organic matter (OM)
content but also to mineral surfaces present in soils. Norflurazon
sorption increases largely after amendment in soils with low
OM content, but the addition of exogenous OM to soils with medium
OM content and/or other available adsorptive surfaces did not
significantly affect norflurazon sorption. Even in some cases
pesticide sorption decreases, due to the blocking of the mineral
and organic soil surfaces with the amendment added. Transformation
of exogenous OM during incubation depends both on the amendment
added and on the type of soil and can affect sorption-desorption
behavior of the soils surfaces in different manner, due to the
modification of their hydrophobic-hydrophilic characteristics.
Norflurazon desorption from original soils
showed hysteresis in all cases, but it was not affected or even
decreased in amended soils. It was a nonexpected behavior, especially
in sandy soil, since it is generally assumed that a higher sorption
always implies a lower mobility in soils. Norflurazon sorption
must be taking place on very low affinity sites on exogenous
OM through weak bindings, from which the pesticide can be easily
desorbed. The application to soils of the organic amendments
used in the present study could not be accepted to reduce norflurazon
losses due to leaching processes.
PMID: 12387404
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12240995&dopt=Abstract
Z Naturforsch
[C]. 2002 Jul-Aug;57(7-8):671-9.
Bansformation
of tobacco with a mutated cyanobacterial phytoene desaturase
gene confers resistance to bleaching herbicides.
Wagner
T, Windhovel U, Romer S.
Lehrstuhl
fur Physiologie und Biochemie der Pflanzen, Universitat Konstanz,
Germany.
Carotenoids
are constituents of the photosynthetic apparatus and essential
for plant survival because of their involvement in protection
of chlorophylls against photooxidation. Certain classes of herbicides
are interfering with carotenoid biosynthesis leading to pigment
destruction and a bleached plant phenotype. One important target
site for bleaching herbicides is the enzyme phytoene desaturase
catalysing the desaturation of phytoene in zeta-carotene. This
enzymatic reaction can be inhibited by norflurazon or fluridone.
We have transformed tobacco with a mutated cyanobacterial phytoene
desaturase gene (pds) derived from the Synechococcus PCC 7942
mutant NFZ4. Characterization of the resulting transformants
revealed an up to 58 fold higher norflurazon resistance in comparison
to wild type controls. The tolerance for fluridone was also
increased 3 fold in the transgenics. Furthermore, the transformed
tobacco maintained a higher level of D1 protein of photosystem
II indicating a lower susceptibility to photooxidative damage
in the presence of norflurazon. In contrast, the genetic manipulation
did not confer herbicide resistance against zeta-carotene desaturase
inhibitors.
PMID: 12240995
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12012067&dopt=Abstract
Bull Environ
Contam Toxicol. 2002 Jun;68(6):901-7.
No
Abstract available
Leaching
and sorption of norflurazon
in soils as affected by cationic surfactants.
Singh
M, Tan S, Sharma SD.
University
of Florida, Institute of Food and Agricultural Sciences, Citrus
Research and Education Center, 700 Experiment Station Road,
Lake Alfred, FL 33850, USA.
PMID: 12012067
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11517722&dopt=Abstract
Pest Manag
Sci. 2001 Aug;57(8):688-94.
Ethyl
cellulose polymer microspheres for controlled release of norfluazon.
Perez-Martinez
JI, Morillo E, Maqueda C, Gines JM.
Departamento
de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia,
Universidad de Sevilla, 41012-Sevilla, Spain. jiperez@irnase.csic.es
The pesticide
norfluazon has been microencapsulated using ethyl cellulose
to develop controlled-release formulations that decrease its
mobility through the soil and protect it from photodegradation.
Ethyl cellulose microspheres loaded with norfluazon were prepared
by the solvent-evaporation method. To obtain the microspheres,
certain conditions (pesticide/polymer ratio, percentage of emulsifying
agent and solvent) were varied. The shape and size of the microspheres
obtained were studied by scanning electron microscopy. Other
parameters, such as solids recovery, encapsulation efficiency
and pesticide loading, were also studied. The release rate of
norfluazon from the different microspheres was slower than that
of pure norfluazon. In particular, microspheres obtained with
o-xylene, which provided the largest diameter, retarded the
initial release of the pesticide relative to microspheres obtained
with chloroform, or to pure norfluazon. Moreover, the studies
showed that the pesticide/polymer ratio controlled the release
of norfluazon, which was slower when this ratio was low. Release
rates conformed to a generalised kinetic equation for a diffusion-controlled
release mechanism, and the time taken for 50% of the active
ingredient to be released into water, t50, was calculated.
PMID:
11517722 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10736764&dopt=Abstract
J Environ
Sci Health B. 2000 Mar;35(2):121-41.
Laboratory
study on leachability of five herbicides in South Australian
soils.
Ying
GG, Williams B.
Department
of Environmental Science & Management, University of Adelaide,
Roseworthy, Australia.
Norflurazon,
oxadiazon, oxyfluorfen, trifluralin and simazine are herbicides
widely used in the vineyards of the Barossa
Valley, South Australia. The leaching behaviour of norflurazon,
oxadiazon, oxyfluorfen and trifluralin was investigated on four
key soils in the Barossa Valley. Leaching potential on packed
soil columns and actual mobility using intact soil columns were
investigated. On the packed soil columns, norflurazon was the
most leachable herbicide. More of the herbicides were detected
in the leachates from the sandy soils (Mountadam and Nuriootpa)
than from the clayey soils (Lyndoch and Tanunda). Organic matter
is generally low in soils in the Barossa region. Porosity and
saturated conductivity significantly affect herbicide movement
and in the sandy Mountadam and Nuriootpa soils, the water flux
is greater than for the higher clay content Lyndoch and Tanunda
soils. Increasing the time interval between herbicide application
and the incidence of "rainfall" reduced the amounts of herbicides
found in the leachates. The use of intact soil columns and including
simazine for comparison showed that both norflurazon and simazine
were present in the leachates. Simazine was the first herbicide
to appear in leachates. Sectioning of the intact soil columns
after leaching clearly demonstrated that norflurazon and simazine
reached the bottom of the soil columns for all soils studied.
Greater amounts of norflurazon were retained
in the soil columns compared with simazine. The other
herbicides were mostly retained in the initial sections of the
soil columns.
PMID: 10736764
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10085175&dopt=Abstract
Bull Environ
Contam Toxicol. 1999 Mar;62(3):315-23.
No
Abstract available
Reduction
of norflurazon leaching in a sandy soil by adjuvants.
Chandran
RS, Singh M.
University
of Florida, Institute of Food and Agricultural Sciences, Citrus
Research and Education Center, 700 Experiment Station Road,
Lake Alfred, FL 33850, USA.
PMID: 10085175
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8819332&dopt=Abstract
Plant Physiol.
1996 Sep;112(1):361-70.
Xenobiotic
biotransformation in unicellular green algae. Involvement of
cytochrome P450 in the activation and selectivity of the pyridazinone
pro-herbicide metflurazon.
Thies
F, Backhaus T, Bossmann B, Grimme LH.
Department
of Biology/Chemistry, University of Bremen, Germany.
The N-demethylation
of the pyridazinone pro-herbicide metflurazon into norflurazon
implies a toxification in photosynthetic organisms. This is
confirmed by quantitative structure activity relationships determined
for two unicellular green algae, Chlorella sorokiniana and Chlorella
fusca; however, the latter is 25 to 80 times more sensitive
to metflurazon. This sensitivity is linked to differences in
the N-demethylase activity of both algae, as determined by an
optimized in vivo biotransformation assay. Apparent K(m) values
of the metflurazon-N-demethylase indicate a 10-fold higher affinity
for this xenobiotic substrate for Chlorella fusca. Furthermore,
algal metflurazon-N-demethylation is characterized by distinct
variations in activity, depending on the stage of cell development
within the cell cycle. Several well-established inhibitors of
cytochrome P450-mediated reactions, including piperonylbutoxide,
1-aminobenzotriazole, 1-phenoxy-3-(1H-1,2,4-triol-1yl)-4-hydroxy-5,5-dimethylhexane++
+, and tetcyclacis, as well as cinnamic acid, a potential endogenous
substrate, inhibited the N-demethylation of metflurazon. The
results suggest that the N-demethylation of metflurazon by both
algae is mediated by a cytochrome P450 monooxygenase. The determination
of antigenic cross-reactivity of algal proteins with heterologous
polyclonal antibodies originally raised against plant P450s,
anti-cinnamic acid 4-hydroxylase (CYP73A1), anti-ethoxycoumarin-O-dealkylase,
anti-tulip allene oxidase (CYP74), and an avocado P450 (CYP71A1)
or those of bacterial origin, CYP105A1 and CYP105B1, suggests
the presence of distinct P450 isoforms in both algae.
PMID: 8819332
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9118639&dopt=Abstract
Contact
Dermatitis. 1996 Dec;35(6):369-70.
No
Abstract available
Allergic
contact dermatitis from norflurazon (Predict).
Leow
YH, Maibach HL.
Department
of Dermatology, University of California, School of Medicine,
San Francisco 94143, USA.
PMID: 9118639
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8520141&dopt=Abstract
Bull Environ
Contam Toxicol. 1995 Sep;55(3):359-65.
No
Abstract available
Effects
of cationic surfactants on leaching of bromacil and norflurazon.
Tan
S, Singh M.
University
of Florida, IFAS, Citrus Research and Education Center, Lake
Alfred 33850, USA.
PMID: 8520141
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8428126&dopt=Abstract
Bull Environ
Contam Toxicol. 1993 Mar;50(3):449-57.
No
Abstract available
Effect
of acrylic polymer adjuvants on leaching of bromacil, diuron,
norflurazon, and simazine in soil columns.
Reddy
KN, Singh M.
University
of Florida, Institute of Food and Agricultural Sciences, Lake
Alfred 33850.
PMID: 8428126
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8428125&dopt=Abstract
Bull Environ
Contam Toxicol. 1993 Mar;50(3):441-8.
No
Abstract available
Leaching
losses of norflurazon through Mississippi River alluvial soil.
Southwick
LM, Willis GH, Bengtson RL.
U.S.
Department of Agriculture,
ARS, Baton Rouge, Louisiana 70894.
PMID: 8428125
[PubMed - indexed for MEDLINE]
Full
free article available at http://www.jbc.org/cgi/reprint/267/34/24732.pdf
J Biol Chem.
1992 Dec 5;267(34):24732-7.
UV light
stress induces the synthesis of the early light-inducible protein
and prevents its degradation.
Adamska
I, Kloppstech K, Ohad I.
Department
of Biological Chemistry, University of Jerusalem, Israel.
ELIP is
a nuclear-encoded protein localized in the thylakoid membranes.
The protein is specifically induced by blue light in mature,
light-grown plants (Adamska, I., Ohad, I., and Kloppstech, K.
(1992) Proc. Natl. Acad. Sci. U. S. A. 89, 2610-2613), as well
as in plants developed in the light in which pigment synthesis
and plastid development were inhibited by the bleaching herbicide
norflurazon. ELIP transcription and protein accumulation are
induced also by UVA but not by UVB light. However, UVB light
allows ELIP synthesis induced by superimposed white light. The
protein is stable under light stress including UVA and UVB light,
but it is rapidly degraded upon cessation of the light stress
conditions. ELIP synthesis and integration into the chloroplast
membranes is related neither to chloroplast translation activity
nor to photosynthetic electron flow. Inhibition of carotenoid
synthesis by fluridone, a bleaching herbicide which causes extensive
damage to the photosynthetic apparatus, does not affect induction
of ELIP transcription during light stress but greatly enhances
ELIP accumulation. Based on these results it is proposed that
ELIP turnover is related to the light stress and recovery process
in plants.
PMID: 1280268
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1907510&dopt=Abstract
Plant Mol
Biol. 1991 Jun;16(6):967-74.
The
molecular basis
of resistance to the herbicide norflurazon.
Chamovitz
D, Pecker I, Hirschberg J.
Department
of Genetics, Hebrew University of Jerusalem, Israel.
We have
cloned and sequenced a gene, pds, from the cyanobacterium Synechococcus
PCC7942 that is responsible for resistance to the bleaching
herbicide norflurazon. A point mutation in that gene, leading
to an amino acid substitution from valine to glycine in its
polypeptide product, was found to confer this resistance. Previous
studies with herbicide-resistant mutants have indicated that
this gene encodes phytoene desaturase (PDS), a key enzyme in
the biosynthesis of carotenoids. A short amino acid sequence
that is homologous to conserved motifs in the binding sites
for NAD(H) and NADP(H) was identified in PDS, suggesting the
involvement of these dinucleotides as cofactors in phytoene
desaturation.
PMID: 1907510
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2175225&dopt=Abstract
Bull Environ
Contam Toxicol. 1990 Sep;45(3):365-74.
No
Abstract available
Sorption
of bromacil, diuron, norflurazon, and simazine at various horizons
in two soils.
Alva
AK, Singh M.
University
of Florida, Institute of Food and Agricultural Sciences, Citrus
Research and Education Center, Lake Alfred 33850.
PMID: 2175225
[PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=4027433&dopt=Abstract
Bull Environ
Contam Toxicol. 1985 Aug;35(2):279-84.
Movement
of bromacil and norflurazon in a sandy soil in Florida.
Singh
M, Castle WS, Achhireddy NR.
PMID: 4027433
[PubMed - indexed for MEDLINE]
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