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1.
J Agric Food Chem ; 71(47): 18212-18226, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37677080

RESUMO

In the search for new chemical entities that can control resistant weeds by addressing novel modes of action (MoAs), we were interested in further exploring a compound class that contained a 1,8-naphthyridine core. By leveraging scaffold hopping methodologies, we were able to discover the new thiazolopyridine compound class that act as potent herbicidal molecules. Further biochemical investigations allowed us to identify that the thiazolopyridines inhibit acyl-acyl carrier protein (ACP) thioesterase (FAT), with this being further confirmed via an X-ray cocrystal structure. Greenhouse trials revealed that the thiazolopyridines display excellent control of grass weed species in pre-emergence application coupled with dose response windows that enable partial selectivity in certain crops.


Assuntos
Herbicidas , Herbicidas/química , Plantas Daninhas/metabolismo , Tioléster Hidrolases/metabolismo , Produtos Agrícolas/metabolismo , Controle de Plantas Daninhas/métodos
2.
Front Plant Sci ; 14: 1335764, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38288413

RESUMO

Safeners are agrochemicals co-applied with herbicides that facilitate selective control of weeds by protecting monocot crops from chemical injury through enhancing the expression of detoxifying enzymes such as glutathione transferases (GSTs). Even though the application of safeners causes the induction of genes encoding GSTs in model dicots such as Arabidopsis thaliana, safeners do not protect broadleaf crops from herbicide injury. In this study, we proposed that the localized induction of Arabidopsis GSTs and the fundamental differences in their detoxifying activity between dicot and monocot species, underpin the failure of safeners to protect Arabidopsis from herbicide toxicity. Using the herbicide safener, isoxadifen-ethyl, we showed that three tau (U) family GSTs namely AtGSTU7, AtGSTU19 and AtGSTU24 were induced with different magnitude by isoxadifen treatment in root and rosette tissues. The higher magnitude of inducibility of these AtGSTUs in the root tissues coincided with the enhanced metabolism of flufenacet, a herbicide that is active in root tissue, protecting Arabidopsis plants from chemical injury. Assay of the recombinant enzyme activities and the significant reduction in flufenacet metabolism determined in the T-DNA insertion mutant of AtGSTU7 (gstu7) in Arabidopsis plants identified an important function for AtGSTU7 protein in flufenacet detoxification. In-silico structural modeling of AtGSTU7, suggested the unique high activity of this enzyme toward flufenacet was due to a less constrained active site compared to AtGSTU19 and AtGSTU24. We demonstrate here that it is possible to induce herbicide detoxification in dicotyledonous plants by safener treatment, albeit with this activity being restricted to very specific combinations of herbicide chemistry, and the localized induction of enzymes with specific detoxifying activities.

3.
J Agric Food Chem ; 70(21): 6368-6376, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35583469

RESUMO

Monitoring agrochemical distribution within plant tissues delivers significant insights into the adsorption, distribution, metabolism, and elimination of agrochemicals. Detection and imaging of the safener cyprosulfamide (CSA) and the herbicide thiencarbazone-methyl (TCM) after micro-droplet application on the surface of maize leaves (Zea mays L.) have been achieved using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI). The agrochemicals were deposited onto the adaxial surface of maize leaves on growing plants, and their uptake, distribution, and metabolism were investigated at four timepoints (3 h, 24 h, 4 days, and 7 days) to assess the influence of CSA treatment on TCM metabolism. MALDI MSI visualized significant changes for the metabolism of TCM after 24 h. Although TCM metabolism was detected neither in the control without the safener nor in the approach with CSA on the second leaf, the co-application on the same leaf showed significant metabolism of the herbicide by detecting the metabolite N-demethylated TCM. These findings suggest that safener protection against herbicide injury is a rapid process in which CSA and TCM need to be present in the same tissues. This study showcases the use of MALDI MSI to visualize and analyze indirect interactions of two substances in planta.


Assuntos
Herbicidas , Zea mays , Agroquímicos/metabolismo , Herbicidas/metabolismo , Folhas de Planta , Plantas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Zea mays/metabolismo
4.
Bioorg Med Chem ; 28(22): 115725, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-33007548

RESUMO

New phosphorous-containing lead structures against drought stress in crops interacting with RCAR/(PYR/PYL) receptor proteins were identified starting from in-depth SAR studies of related sulfonamide lead structures and protein docking studies. A converging 6-step synthesis via phosphinic chlorides and phosphono chloridates as key intermediates afforded envisaged tetrahydroquinolinyl phosphinamidates and phosphonamidates. Whilst tetrahydroquinolinyl phosphonamidates 13a,b exhibited low to moderate target affinities, the corresponding tetrahydroquinolinyl phosphinamidates 12a,b revealed confirmed strong affinities for RCAR/ (PYR/PYL) receptor proteins in Arabidopsis thaliana on the same level as essential plant hormone abscisic acid (ABA) combined with promising efficacy against drought stress in vivo (broad-acre crops wheat and canola).


Assuntos
Amidas/farmacologia , Produtos Agrícolas/efeitos dos fármacos , Secas , Compostos Organofosforados/farmacologia , Proteínas de Plantas/química , Quinolinas/farmacologia , Ácido Abscísico/metabolismo , Amidas/química , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Produtos Agrícolas/metabolismo , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Simulação de Acoplamento Molecular , Estrutura Molecular , Compostos Organofosforados/química , Proteínas de Plantas/metabolismo , Quinolinas/química , Relação Estrutura-Atividade
5.
Pest Manag Sci ; 76(10): 3413-3422, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32083366

RESUMO

BACKGROUND: Safeners extend the application of existing herbicides by selectively enhancing tolerance in large-grained cereal crops. While their activity is linked to enhanced herbicide metabolism, their exact mode of action and reasons for their crop specificity have yet to be determined. In this study, we investigated the selectivity of the recently developed sulfonamide safener cyprosulfamide (CSA) in maize (Zea mays L.) and wheat (Triticum aestivum), focusing on its uptake, distribution and metabolism in the two species. RESULTS: CSA protected maize, but not wheat, from injury by thiencarbazone-methyl (TCM). This correlated with the selective enhanced detoxification of the herbicide in maize. CSA underwent more rapid metabolism in maize than in wheat, with the formation of a specific hydroxylated metabolite correlating with safening. Studies with the nsf1 mutant sweetcorn line showed that the hydroxylation of CSA was partly mediated by the cytochrome P450 CYP81A9. However, primary metabolites of CSA were chemically synthesised and tested for their ability to safen TCM in maize but when tested were inactive as safeners. CONCLUSION: The results of this study suggest that the protection against TCM injury by CSA is linked to enhanced herbicide metabolism. This selective activity is due to the specific recognition of parent CSA in maize but not in wheat. Subsequent rapid oxidative metabolism of CSA led to its inactivation, demonstrating that cytochrome P450s regulate the activity of safeners as well as herbicides. © 2020 Society of Chemical Industry.


Assuntos
Triticum , Zea mays , Herbicidas
6.
Bioorg Med Chem ; 27(24): 115142, 2019 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-31685332

RESUMO

Novel synthetic lead structures interacting with RCAR/(PYR/PYL) receptor proteins were identified based on the results of a high-throughput screening campaign of a large compound library followed by focused SAR studies of the three most promising hit clusters. Whilst indolinylmethyl sulfonamides 8y,z and phenylsulfonyl ethylenediamines 9y,z showed strong affinities for RCAR/ (PYR/PYL) receptor proteins in wheat, thiotriazolyl acetamides 7f,s exhibited promising efficacy against drought stress in vivo (wheat, corn and canola) combined with confirmed target interaction in wheat and arabidopsis thaliana. Remarkably, binding affinities of several representatives of 8 and 9 were on the same level or even better than the essential plant hormone abscisic acid (ABA).


Assuntos
Ácido Abscísico/análogos & derivados , Reguladores de Crescimento de Plantas/química , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/química , Ácido Abscísico/química , Ácido Abscísico/farmacologia , Produtos Agrícolas , Secas , Descoberta de Drogas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ensaios de Triagem em Larga Escala , Estrutura Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ligação Proteica , Sulfonamidas , Triticum/genética , Triticum/metabolismo
7.
Plant Physiol ; 168(3): 814-27, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26023163

RESUMO

Arabidopsis (Arabidopsis thaliana) penetration (PEN) genes quantitatively contribute to the execution of different forms of plant immunity upon challenge with diverse leaf pathogens. PEN3 encodes a plasma membrane-resident pleiotropic drug resistance-type ATP-binding cassette transporter and is thought to act in a pathogen-inducible and PEN2 myrosinase-dependent metabolic pathway in extracellular defense. This metabolic pathway directs the intracellular biosynthesis and activation of tryptophan-derived indole glucosinolates for subsequent PEN3-mediated efflux across the plasma membrane at pathogen contact sites. However, PEN3 also functions in abiotic stress responses to cadmium and indole-3-butyric acid (IBA)-mediated auxin homeostasis in roots, raising the possibility that PEN3 exports multiple functionally unrelated substrates. Here, we describe the isolation of a pen3 allele, designated pen3-5, that encodes a dysfunctional protein that accumulates in planta like wild-type PEN3. The specific mutation in pen3-5 uncouples PEN3 functions in IBA-stimulated root growth modulation, callose deposition induced with a conserved peptide epitope of bacterial flagellin (flg22), and pathogen-inducible salicylic acid accumulation from PEN3 activity in extracellular defense, indicating the engagement of multiple PEN3 substrates in different PEN3-dependent biological processes. We identified 4-O-ß-D-glucosyl-indol-3-yl formamide (4OGlcI3F) as a pathogen-inducible, tryptophan-derived compound that overaccumulates in pen3 leaf tissue and has biosynthesis that is dependent on an intact PEN2 metabolic pathway. We propose that a precursor of 4OGlcI3F is the PEN3 substrate in extracellular pathogen defense. These precursors, the shared indole core present in IBA and 4OGlcI3F, and allele-specific uncoupling of a subset of PEN3 functions suggest that PEN3 transports distinct indole-type metabolites in distinct biological processes.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Alelos , Arabidopsis/metabolismo , Redes e Vias Metabólicas , Mutação/genética , Triptofano/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Sequência de Aminoácidos , Substituição de Aminoácidos , Arabidopsis/efeitos dos fármacos , Arabidopsis/microbiologia , Ascomicetos/fisiologia , Suscetibilidade a Doenças , Indóis/farmacologia , Redes e Vias Metabólicas/efeitos dos fármacos , Modelos Biológicos , Dados de Sequência Molecular , Moléculas com Motivos Associados a Patógenos/metabolismo , Doenças das Plantas/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Ácido Salicílico/metabolismo
8.
EMBO J ; 25(18): 4400-11, 2006 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-16957775

RESUMO

Plants use sophisticated strategies to balance responses to oxidative stress. Programmed cell death, including the hypersensitive response (HR) associated with successful pathogen recognition, is one cellular response regulated by reactive oxygen in various cellular contexts. The Arabidopsis basic leucine zipper (bZIP) transcription factor AtbZIP10 shuttles between the nucleus and the cytoplasm and binds consensus G- and C-box DNA sequences. Surprisingly, AtbZIP10 can be retained outside the nucleus by LSD1, a protein that protects Arabidopsis cells from death in the face of oxidative stress signals. We demonstrate that AtbZIP10 is a positive mediator of the uncontrolled cell death observed in lsd1 mutants. AtbZIP10 and LSD1 act antagonistically in both pathogen-induced HR and basal defense responses. LSD1 likely functions as a cellular hub, where its interaction with AtbZIP10 and additional, as yet unidentified, proteins contributes significantly to plant oxidative stress responses.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Apoptose , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Citoplasma/metabolismo , Proteínas de Ligação a DNA/genética , Genes de Plantas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Mutação , Oomicetos/patogenicidade , Estresse Oxidativo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/genética , Técnicas do Sistema de Duplo-Híbrido
9.
Plant Cell ; 18(3): 731-46, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16473969

RESUMO

Arabidopsis thaliana is a host to the powdery mildew Erysiphe cichoracearum and nonhost to Blumeria graminis f. sp hordei, the powdery mildew pathogenic on barley (Hordeum vulgare). Screening for Arabidopsis mutants deficient in resistance to barley powdery mildew identified PENETRATION3 (PEN3). pen3 plants permitted both increased invasion into epidermal cells and initiation of hyphae by B. g. hordei, suggesting that PEN3 contributes to defenses at the cell wall and intracellularly. pen3 mutants were compromised in resistance to the necrotroph Plectosphaerella cucumerina and to two additional inappropriate biotrophs, pea powdery mildew (Erysiphe pisi) and potato late blight (Phytophthora infestans). Unexpectedly, pen3 mutants were resistant to E. cichoracearum. This resistance was salicylic acid-dependent and correlated with chlorotic patches. Consistent with this observation, salicylic acid pathway genes were hyperinduced in pen3 relative to the wild type. The phenotypes conferred by pen3 result from the loss of function of PLEIOTROPIC DRUG RESISTANCE8 (PDR8), a highly expressed putative ATP binding cassette transporter. PEN3/PDR8 tagged with green fluorescent protein localized to the plasma membrane in uninfected cells. In infected leaves, the protein concentrated at infection sites. PEN3/PDR8 may be involved in exporting toxic materials to attempted invasion sites, and intracellular accumulation of these toxins in pen3 may secondarily activate the salicylic acid pathway.


Assuntos
Transportadores de Cassetes de Ligação de ATP/fisiologia , Arabidopsis/metabolismo , Arabidopsis/microbiologia , Doenças das Plantas/microbiologia , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Arabidopsis/genética , Ascomicetos/patogenicidade , Morte Celular/fisiologia , Ciclopentanos/metabolismo , Perfilação da Expressão Gênica , Imunidade Inata/fisiologia , Modelos Biológicos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Oomicetos/patogenicidade , Oxilipinas , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Folhas de Planta/microbiologia , Estrutura Terciária de Proteína , Ácido Salicílico/metabolismo , Alinhamento de Sequência , Transdução de Sinais
10.
Science ; 310(5751): 1180-3, 2005 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-16293760

RESUMO

Nonhost resistance describes the immunity of an entire plant species against nonadapted pathogen species. We report that Arabidopsis PEN2 restricts pathogen entry of two ascomycete powdery mildew fungi that in nature colonize grass and pea species. The PEN2 glycosyl hydrolase localizes to peroxisomes and acts as a component of an inducible preinvasion resistance mechanism. Postinvasion fungal growth is blocked by a separate resistance layer requiring the EDS1-PAD4-SAG101 signaling complex, which is known to function in basal and resistance (R) gene-triggered immunity. Concurrent impairment of pre- and postinvasion resistance renders Arabidopsis a host for both nonadapted fungi.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/imunologia , N-Glicosil Hidrolases/fisiologia , Doenças das Plantas/microbiologia , Proteínas Qa-SNARE/fisiologia , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Ascomicetos/fisiologia , Hidrolases de Éster Carboxílico/fisiologia , Proteínas de Ligação a DNA/fisiologia , Mutação , Peroxissomos/fisiologia , Phytophthora/fisiologia , Proteínas Qa-SNARE/genética , Transdução de Sinais
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