CAS No. 27314-13-2

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ACTIVITY: Herbicide (pyridazinone)

Note: Two breakdown products: Demethylnorflurazon (CAS No. 112748-69-3) and Desmethylnorflurazon (CAS No. 23576-24-1)

CAS Name: 4-chloro-5-(methylamino)-2-[3-(trifluoromethyl)phenyl]-3(2H)-pyridazinone


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Order No. Title Abstract



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.


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.



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.



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



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.



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.


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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]


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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