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1.
Plant Cell ; 35(9): 3604-3625, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37325884

RESUMO

Catalase (CAT) is often phosphorylated and activated by protein kinases to maintain hydrogen peroxide (H2O2) homeostasis and protect cells against stresses, but whether and how CAT is switched off by protein phosphatases remains inconclusive. Here, we identified a manganese (Mn2+)-dependent protein phosphatase, which we named PHOSPHATASE OF CATALASE 1 (PC1), from rice (Oryza sativa L.) that negatively regulates salt and oxidative stress tolerance. PC1 specifically dephosphorylates CatC at Ser-9 to inhibit its tetramerization and thus activity in the peroxisome. PC1 overexpressing lines exhibited hypersensitivity to salt and oxidative stresses with a lower phospho-serine level of CATs. Phosphatase activity and seminal root growth assays indicated that PC1 promotes growth and plays a vital role during the transition from salt stress to normal growth conditions. Our findings demonstrate that PC1 acts as a molecular switch to dephosphorylate and deactivate CatC and negatively regulate H2O2 homeostasis and salt tolerance in rice. Moreover, knockout of PC1 not only improved H2O2-scavenging capacity and salt tolerance but also limited rice grain yield loss under salt stress conditions. Together, these results shed light on the mechanisms that switch off CAT and provide a strategy for breeding highly salt-tolerant rice.


Assuntos
Oryza , Catalase/genética , Catalase/metabolismo , Oryza/metabolismo , Peróxido de Hidrogênio/metabolismo , Proteína Fosfatase 1/metabolismo , Tolerância ao Sal/genética , Homeostase , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
J Nanosci Nanotechnol ; 16(1): 840-3, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27398533

RESUMO

A colorimetric assay has been developed for detection of Cd²âº utilizing DL-mercaptosuccinic acid-modified gold nanoparticles (MSA-AuNPs). The method showed good selectivity for Cd²âº over other metal ions. As a result, the linear relationships (r > 0.9606) between concentration 0.07 mM and 0.20 mM for cadmium ion were obtained. The detection limit was as low as 0.07 mM by the naked eye. The effect of pH on the aggregation was optimized. The MSA-AuNPs probe could be used to detect Cd²âº in an aqueous solution based on the aggregation-induced color change of MSA-AuNPs.


Assuntos
Cádmio/análise , Ouro/química , Nanopartículas Metálicas/química , Tiomalatos/química , Íons/análise
3.
Int J Mol Sci ; 15(1): 574-87, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24398982

RESUMO

Atrazine molecular imprinted polymers (MIPs) were comparatively synthesized using identical polymer formulation by far-infrared (FIR) radiation and ultraviolet (UV)-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIP(uv) possessed specific binding to atrazine compared with their MIP(FIR) radiation counterparts. Scatchard plot's of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high- and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF) and different selectivity index (SI) for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM), Fourier transform infrared absorption (FT-IR), and mercury analyzer (MA). Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE) of atrazine from lake water, followed by high performance liquid chromatography (HPLC) analysis. Compared with commercial C18 SPE sorbent (86.4%-94.8%), higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%-97.1% and 94.4%-101.9%, for both MIPs, respectively.


Assuntos
Atrazina/química , Impressão Molecular , Polímeros/química , Adsorção , Atrazina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Raios Infravermelhos , Polimerização/efeitos da radiação , Polímeros/síntese química , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Raios Ultravioleta , Água/química
4.
J Sep Sci ; 36(8): 1429-36, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23526680

RESUMO

In this paper, a new approach to prepare monolithic molecularly imprinted polymer (MIP) fibers for solid-phase microextraction is proposed with the help of microwave irradiation. Imprinting polymerization was carried out within silica capillaries in 4.5 min, using dimethyl phthalate (DMP) as a template molecular, α-methacrylic acid as a functional monomer and ethylene dimethacrylate as a crosslinker, acetonitrile as the porogenic solvent. The synthesis was optimized by varying the ratio of template/monomer and different volume of porogen. The resulted MIP fibers were obtained after silica being etched away with a controlled length of 1 cm, and subsequently characterized by SEM. In order to increase the selective extraction of DMP, factors affecting the extraction including extraction time, salt concentration, desorption time, and desorption solvents were investigated for solid-phase microextraction procedures in detail. The selectivity coefficients, defined as the extraction amount ratio of MIP to its nonimprinting fiber, were 5.6, 2.6, and 1.4 for DMP and its counterpart including dibutyl phthalate and di-n-octylo-phthalate, respectively. The resulted fibers were also applied to detect DMP, dibutyl phthalate, and di-n-octylo-phthalate in bottled beverage samples coupled to HPLC and resulted in relative recoveries of up to 73.8-98.5%, respectively.

5.
Pest Manag Sci ; 79(12): 5237-5249, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37595063

RESUMO

BACKGROUND: Weeds grow aggressively in agricultural fields, leading to reduced crop yields and an inability to meet the growing demand for food. Herbicides are currently the most effective method for weed control. However, the overuse of herbicides has resulted in the evolution of resistance mutants and has caused environmental pollution. Therefore, new technologies are urgently required to address this global challenge. RESULTS: We report a copper-benzene-1,4-dicarboxylate metal organic framework (Cu-BDC MOF)-functionalized carboxyl hollow mesoporous silica (HMS-COOH) delivery system for the pH-controlled release of the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide quizalofop-p-ethyl (QE). The delivery system (QE@HMS@Cu-BDC) enabled the efficient control of barnyard grasses that are susceptible and resistant to ACCase-inhibiting herbicides, which showed 93.33% and 88.33% FW control efficacy at 67.5 g ha-1 , respectively. With the lowest pH value (3), QE and copper ion were released slowly to total 70.30% and 78.55% levels (respectively) from QE@HMS@Cu-BDC after 89 h. QE@HMS@Cu-BDC showed better absorption, conduction, transportation and ACCase activity inhibition performance than that of QE emulsifiable concentrate (EC) in both susceptible and ACCase-herbicide resistant barnyard grasses. In addition, with the safener effect of carrier HMS@Cu-BDC and the aid of the safener fenchlorazole-ethyl (FE), the application of QE@HMS@Cu-BDC was shown to mitigate the damage caused by QE to rice plants. CONCLUSION: This work found that the new material HMS-COOH@Cu-BDC can be used to mitigate herbicide-induced oxidative stress and improve rice plant safety. Futhermore, the QE@HMS-COOH@Cu-BDC constructed in this research might be used as an efficient nanopesticide formulation for weed controls in paddy rice fields. © 2023 Society of Chemical Industry.


Assuntos
Herbicidas , Oryza , Herbicidas/farmacologia , Acetil-CoA Carboxilase/genética , Cobre/farmacologia , Dióxido de Silício/farmacologia , Plantas Daninhas , Concentração de Íons de Hidrogênio , Resistência a Herbicidas
6.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2293-2298, 2020 Jul.
Artigo em Zh | MEDLINE | ID: mdl-32715694

RESUMO

The effects of exogenous methyl jasmonate (MeJA) on the resistance levels to quinclorac and endogenous hormone levels were examined using the resistant and sensitive biotypes of barnyardgrass with the same genetic background. The results showed that exogenous MeJA could significantly increase the resistance of resistant plants to quinclorac, but did not affect the resistance of sensitive plants. There were significant differences in the contents of indole-3-acetic acid (IAA), abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) among the tested materials. Quinclorac treatment could significantly increase the contents of ABA, SA, and JA in barnyardgrass, with stronger increase of ABA and JA contents in the sensitive plants. Exogenous MeJA could significantly enhance the induction of ABA and JA contents by quinclorac, especially in the sensitive biotypes. These results showed that rapid hormone variations in sensitive plants inhibited their response to herbicide, while gentle hormone variations endowed resistant plants with a strong adapta-bility to herbicide, which closely related to the enhanced resistance by MeJA. ABA and JA hormone signals might play an important role in the resistance of barnyardgrass to quinclorac stress.


Assuntos
Echinochloa , Quinolinas , Acetatos , Ciclopentanos , Oxilipinas
7.
PLoS One ; 14(4): e0214480, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947307

RESUMO

Echinochloa crusgalli (L.) Beauv. (barnyard grass) is considered a noxious weed worldwide, and is the most pernicious weed decreasing rice yields in China. Recently, E. crusgalli has evolved quinclorac resistance, making it among the most serious herbicide resistant weeds in China. The present study explored differences in germination and growth between quinclorac-resistant and -susceptible E. crusgalli collected in Hunan Province. The order of the seven E. crusgalli biotypes assessed, from high to low quinclorac-resistance, was: quinclorac-resistant, Chunhua, Hanshou, Shimen, Hekou, Dingcheng, and quinclorac-susceptible. With an increased in the level of quinclorac-resistance, the germination rate, length of young shoots and roots, and fresh weight of E. crusgalli were all decreased compared with that in more susceptible biotypes. However, there were no significant differences between quinclorac-resistant and susceptible E. crusgalli biotypes without polyethylene glycol 6000 treatment. Drought had a more obvious effect on glutathione S-transferases (GST) activity, determined by spectrophotometric method, in quinclorac-resistant E. crusgalli. Higher resistance level biotypes showed greater activity, and when treated with polyethylene glycol 6000 for 3 days, all E. crusgalli biotypes showed the highest GST activity. This study demonstrated that as the level of quinclorac-resistance increased, the rate of seed germination decreased, while the growth of young buds, young roots, and fresh weight decreased. Increased quinclorac-resistance may be related to the increased metabolic activity of GST in E. crusgalli.


Assuntos
Secas , Echinochloa/efeitos dos fármacos , Germinação/efeitos dos fármacos , Resistência a Herbicidas , Quinolinas/farmacologia , Sementes/efeitos dos fármacos , China , Echinochloa/enzimologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glutationa Transferase/metabolismo , Herbicidas/farmacologia , Liases/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Polietilenoglicóis , Estresse Fisiológico
9.
J Econ Entomol ; 101(6): 1888-96, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19133471

RESUMO

A full-length cDNA, with an open reading frame (ORF) of 1,449 bp, encoding a subunit of the gamma-aminobutyric acid (GABA)-activated chloride channel was isolated from Plutella xylostella (L.) (Lepidoptera: Plutellidae) (GenBank accession no. EF156251). The subunit gene encoded a 483-amino acid polypeptide that showed 84% sequence identity with DmRdl subunit (U02042) (Drosophila melanogaster resistant to dieldrin). When expressed in Xenopus laevis oocytes, the subunit assembled as a functional homomeric complex activated by GABA and abamectin in a dose-dependent manner. The EC50 value of GABA was 0.49 mM (0.41-0.58) (n = 5). However, the responses to abamectin were very robust, with an EC50 of 4.85 microM (4.02-5.89) (n = 6), indicating that abamectin was > 100-fold more potent in activating chloride currents than GABA. The results suggest that this subunit is vital to the formation of a functional channel and contains the binding site of abamectin.


Assuntos
Proteínas de Insetos/efeitos dos fármacos , Inseticidas/farmacologia , Ivermectina/análogos & derivados , Mariposas/genética , Receptores de GABA/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Condutividade Elétrica , Proteínas de Insetos/química , Proteínas de Insetos/genética , Ivermectina/farmacologia , Dados de Sequência Molecular , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Técnicas de Patch-Clamp , Receptores de GABA/química , Receptores de GABA/genética , Alinhamento de Sequência , Xenopus , Ácido gama-Aminobutírico/farmacologia
10.
Chem Cent J ; 7(1): 129, 2013 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-23890199

RESUMO

BACKGROUND: At present, the study on the homogeneous-phase derivatization of cellulose in ionic liquid is mainly focused on its acetylation. To the best of our knowledge, there has been no such report on the preparation of cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) with ionic liquid 1-allyl-3-methyl-imidazolium chloride (AmimCl) so far. RESULTS: With ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a reaction solvent, cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) was synthesized by the reaction of 3,5-dimethylphenyl isocyanate and soluble microcrystalline cellulose in a homogeneous phase. The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP). The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC). Good chiral separation was obtained using n-hexane and different modifiers as the mobile phases under the optimal percentage and column temperature, with the resolution of metalaxyl, diniconazole, flutriafol, paclobutrazol, hexaconazole, myclobutanil and hexythiazox of 1.73, 1.56, 1.26, 1.00, 1.18, 1.14 and 1.51, respectively. The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization. CONCLUSION: CDMPC was successfully synthesized as the chiral selector by reacting 3, 5-dimethylphenyl isocyanate with dissolved microcrystalline cellulose in a green ionic liquid of AmimCl.

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