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1.
ACS Appl Mater Interfaces ; 16(7): 9293-9302, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38324477

RESUMO

Aramids, renowned for their high-performance attributes, find applications in critical fields such as protective equipment, aerospace components, and industrial filters. However, challenges arise in scenarios in which frequent washing is impractical, leading to bacterial proliferation, especially in textiles. This study outlines a straightforward and scalable method for preparing aramid-coated textiles and films endowed with inherent bactericidal activity, achieved by reacting parent aramids with vanillin. The functionalization of the aramids with bactericide moieties not only preserved the high-performance characteristics of commercial aramids but also improved their crucial mechanical properties. Tensile tests revealed an increase in Young's modulus, up to 50% compared to commercial m-aramid, accompanied by thermal performance comparable to commercial m-aramids. The evaluation of these coated textiles as bactericidal materials demonstrated robust effectiveness with A parameters (antibacterial activity) of 4.31 for S. aureus and 3.44 for K. pneumoniae. Reusability tests (washing the textiles in harsh conditions) underscored that the bactericide-coated textiles maintain their performance over at least 5 cycles. Regarding practical applications, tests performed with reconstructed human epidermis affirmed the nonirritating nature of these materials to the skin. The distinctive qualities of these metal-free intrinsic bactericidal aramids position them as ideal candidates for scenarios demanding a synergy of high performance and bactericidal properties. Applications such as first responders' textiles or filters stand to benefit significantly from these advanced materials.


Assuntos
Antibacterianos , Staphylococcus aureus , Humanos , Antibacterianos/farmacologia , Têxteis , Pele
2.
BMC Plant Biol ; 24(1): 120, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38369495

RESUMO

BACKGROUND: Plants have acquired a repertoire of mechanisms to combat biotic stressors, which may vary depending on the feeding strategies of herbivores and the plant species. Hormonal regulation crucially modulates this malleable defense response. Jasmonic acid (JA) and salicylic acid (SA) stand out as pivotal regulators of defense, while other hormones like abscisic acid (ABA), ethylene (ET), gibberellic acid (GA) or auxin also play a role in modulating plant-pest interactions. The plant defense response has been described to elicit effects in distal tissues, whereby aboveground herbivory can influence belowground response, and vice versa. This impact on distal tissues may be contingent upon the feeding guild, even affecting both the recovery of infested tissues and those that have not suffered active infestation. RESULTS: To study how phytophagous with distinct feeding strategies may differently trigger the plant defense response during and after infestation in both infested and distal tissues, Arabidopsis thaliana L. rosettes were infested separately with the chewing herbivore Pieris brassicae L. and the piercing-sucker Tetranychus urticae Koch. Moderate infestation conditions were selected for both pests, though no quantitative control of damage levels was carried out. Feeding mode did distinctly influence the transcriptomic response of the plant under these conditions. Though overall affected processes were similar under either infestation, their magnitude differed significantly. Plants infested with P. brassicae exhibited a short-term response, involving stress-related genes, JA and ABA regulation and suppressing growth-related genes. In contrast, T. urticae elicited a longer transcriptomic response in plants, albeit with a lower degree of differential expression, in particular influencing SA regulation. These distinct defense responses transcended beyond infestation and through the roots, where hormonal response, flavonoid regulation or cell wall reorganization were differentially affected. CONCLUSION: These outcomes confirm that the existent divergent transcriptomic responses elicited by herbivores employing distinct feeding strategies possess the capacity to extend beyond infestation and even affect tissues that have not been directly infested. This remarks the importance of considering the entire plant's response to localized biotic stresses.


Assuntos
Arabidopsis , Borboletas , Animais , Transcriptoma , Herbivoria/fisiologia , Mastigação , Borboletas/fisiologia , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Ciclopentanos/metabolismo
3.
Redox Biol ; 67: 102902, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37797370

RESUMO

The interaction between plants and phytophagous arthropods encompasses a complex network of molecules, signals, and pathways to overcome defences generated by each interacting organism. Although most of the elements and modulators involved in this interplay are still unidentified, plant redox homeostasis and signalling are essential for the establishment of defence responses. Here, focusing on the response of Arabidopsis thaliana to the spider mite Tetranychus urticae, we demonstrate the involvement in plant defence of the thioredoxin TRXh5, a small redox protein whose expression is induced by mite infestation. TRXh5 is localized in the cell membrane system and cytoplasm and is associated with alterations in the content of reactive oxygen and nitrogen species. Protein S-nitrosylation signal in TRXh5 over-expression lines is decreased and alteration in TRXh5 level produces changes in the JA/SA hormonal crosstalk of infested plants. Moreover, TRXh5 interacts and likely regulates the redox state of an uncharacterized receptor-like kinase, named THIOREDOXIN INTERACTING RECEPTOR KINASE (TIRK), also induced by mite herbivory. Feeding bioassays performed withTRXh5 over-expression plants result in lower leaf damage and reduced egg accumulation after T. urticae infestation than in wild-type (WT) plants. In contrast, mites cause a more severe injury in trxh5 mutant lines where a greater number of eggs accumulates. Likewise, analysis of TIRK-gain and -loss-of-function lines demonstrate the defence role of this receptor in Arabidopsis against T. urticae. Altogether, our findings demonstrate the interaction between TRXh5 and TIRK and highlight the importance of TRXh5 and TIRK in the establishment of effective Arabidopsis defences against spider mite herbivory.


Assuntos
Arabidopsis , Tetranychidae , Animais , Arabidopsis/genética , Tetranychidae/genética , Plantas , Tiorredoxinas/genética , Homeostase
4.
Bio Protoc ; 13(12)2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37397798

RESUMO

Mandelonitrile is a nitrogen-containing compound, considered an essential secondary metabolite. Chemically, it is a cyanohydrin derivative of benzaldehyde, with relevant functions in different physiological processes including defense against phytophagous arthropods. So far, procedures for detecting mandelonitrile have been effectively applied in cyanogenic plant species such as Prunus spp. Nevertheless, its presence in Arabidopsis thaliana , considered a non-cyanogenic species, has never been determined. Here, we report the development of an accurate protocol for mandelonitrile quantification in A. thaliana within the context of A. thaliana -spider mite interaction. First, mandelonitrile was isolated from Arabidopsis rosettes using methanol; then, it was derivatized by silylation to enhance detection and, finally, it was quantified using gas chromatography-mass spectrometry. The selectivity and sensitivity of this method make it possible to detect low levels of mandelonitrile (LOD 3 ppm) in a plant species considered non-cyanogenic that, therefore, will have little to no cyanogenic compounds, using a small quantity of starting material (≥100 mg).

5.
Sens Actuators B Chem ; 379: 133165, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36536612

RESUMO

The initial stages of the pandemic caused by SARS-CoV-2 showed that early detection of the virus in a simple way is the best tool until the development of vaccines. Many different tests are invasive or need the patient to cough up or even drag a sample of mucus from the throat area. Besides, the manufacturing time has proven insufficient in pandemic conditions since they were out of stock in many countries. Here we show a new method of manufacturing virus sensors and a proof of concept with SARS-CoV-2. We found that a fluorogenic peptide substrate of the main protease of the virus (Mpro) can be covalently immobilized in a polymer, with which a cellulose-based material can be coated. These sensory labels fluoresce with a single saliva sample of a positive COVID-19 patient. The results matched with that of the antigen tests in 22 of 26 studied cases (85% success rate).

6.
Food Chem ; 405(Pt A): 134789, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36347201

RESUMO

Glucose oxidase (GOX) and catalase (CAT) regulate the amount of H2O2 in honey, by generating or consuming it, so they are related to the antibacterial and antioxidant activity of honey. However, their activities are hardly analysed, since the process requires a previous dialysis that is non-selective, very time-consuming (>24 h), eco-unfriendly (>6L of buffer) and expensive. This research shows the design and performance of a material that selectively removes the actual interferents. The film-shaped-polymer is immersed for 90́ within a honey solution (12.5 mL of buffer), where it interacts exclusively with 1,2-dihydroxybenzenes, which we proved to be the real interferents (the material contains motifs derived from phenylboronic acid to interact with 1,2-diols). Polymeric chains favour condensation to occur exclusively with 1,2-dihydroxybenzenes, excluding monosaccharides. The interferents' removal using our designed polymer is selective, low cost (1.42€ per test), rapid and eco-friendly (saves 6L of buffer and 20.5 h of experimental workout per sample).


Assuntos
Mel , Mel/análise , Glucose Oxidase , Catalase/análise , Polifenóis/análise , Peróxido de Hidrogênio , Polímeros , Diálise Renal , Glucose
7.
Polymers (Basel) ; 14(22)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36433081

RESUMO

Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer's applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy.

8.
ACS Appl Mater Interfaces ; 14(32): 37051-37058, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35920554

RESUMO

We have developed an in situ methodology for determining nitrite concentration in processed meats that can also be used by unskilled personnel. It is based on a colorimetric film-shaped sensory polymer that changes its color upon contacting the meat and a mobile app that automatically calculates the manufacturing and residual nitrite concentration by only taking digital photographs of sensory films and analyzing digital color parameters. The film-shaped polymer sensor detects nitrite anions by an azo-coupling reaction, since they activate this reaction between two of the four monomers that the copolymer is based on. The sensory polymer is complemented with an app, which analyzes the color in two different digital color spaces (RGB and HSV) and performs a set of 32 data fittings representing the concentration of nitrite versus eight different variables, finally providing the nitrite concentration of the test samples using the best fitting curve. The calculated concentration of nitrite correlates with a validated method (ISO 2918: 1975) usually used to determine nitrite, and no statistically significant difference between these methods and our proposed one has been found in our study (26 meat samples, 8 prepared, and 18 commercial). Our method represents a great advance in terms of analysis time, simplicity, and orientation to use by average citizens.


Assuntos
Colorimetria , Aplicativos Móveis , Colorimetria/métodos , Carne/análise , Nitritos , Polímeros , Smartphone
9.
Sci Rep ; 12(1): 8818, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614307

RESUMO

We have faced the preparation of fully water-soluble fluorescent peptide substrate with long-term environmental stability (in solution more than 35 weeks) and, accordingly, with stable results in the use of this probe in determining the activity of enzymes. We have achieved this goal by preparing a co-polymer of the commercial N-vinyl-2-pyrrolidone (99.5% mol) and a fluorescent substrate for trypsin activity determination having a vinylic group (0.5%). The activity of trypsin has been measured in water solutions of this polymer over time, contrasted against the activity of both the commercial substrate Z-L-Arg-7-amido-4-methylcoumarin hydrochloride and its monomeric derivative, prepared ad-hoc. Initially, the activity of the sensory polymer was 74.53 ± 1.72 nmol/min/mg of enzyme, while that of the commercial substrate was 20.44 ± 0.65 nmol/min/mg of enzyme, the former maintained stable along weeks and the latter with a deep decay to zero in three weeks. The 'protection' effect exerted by the polymer chain has been studied by solvation studies by UV-Vis spectroscopy, steady-state & time resolved fluorescence, thermogravimetry and isothermal titration calorimetry.


Assuntos
Corantes Fluorescentes , Peptídeos , Cinética , Polímeros , Especificidade por Substrato , Tripsina/metabolismo , Água
10.
Plant Physiol ; 189(4): 2244-2258, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35474139

RESUMO

Plant-pest interactions involve multifaceted processes encompassing a complex crosstalk of pathways, molecules, and regulators aimed at overcoming defenses developed by each interacting organism. Among plant defensive compounds against phytophagous arthropods, cyanide-derived products are toxic molecules that directly target pest physiology. Here, we identified the Arabidopsis (Arabidopsis thaliana) gene encoding hydroxynitrile lyase (AtHNL, At5g10300) as one gene induced in response to spider mite (Tetranychus urticae) infestation. AtHNL catalyzes the reversible interconversion between cyanohydrins and derived carbonyl compounds with free cyanide. AtHNL loss- and gain-of-function Arabidopsis plants showed that specific activity of AtHNL using mandelonitrile as substrate was higher in the overexpressing lines than in wild-type (WT) and mutant lines. Concomitantly, mandelonitrile accumulated at higher levels in mutant lines than in WT plants and was significantly reduced in the AtHNL overexpressing lines. After mite infestation, mandelonitrile content increased in WT and overexpressing plants but not in mutant lines, while hydrogen cyanide (HCN) accumulated in the three infested Arabidopsis genotypes. Feeding bioassays demonstrated that the AtHNL gene participated in Arabidopsis defense against T. urticae. The reduced leaf damage detected in the AtHNL overexpressing lines reflected the mite's reduced ability to feed on leaves, which consequently restricted mite fecundity. In turn, mites upregulated TuCAS1 encoding ß-cyanoalanine synthase to avoid the respiratory damage produced by HCN. This detoxification effect was functionally demonstrated by reduced mite fecundity observed when dsRNA-TuCAS-treated mites fed on WT plants and hnl1 mutant lines. These findings add more players in the Arabidopsis-T. urticae interplay to overcome mutual defenses.


Assuntos
Arabidopsis , Tetranychidae , Aldeído Liases/genética , Animais , Arabidopsis/genética , Cianetos , Plantas , Tetranychidae/genética
11.
Int J Infect Dis ; 108: 282-288, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34044145

RESUMO

AIM: The aim of this study was to determine the usefulness of COVID-GRAM and CURB-65 scores as predictors of the severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Caucasian patients. METHODS: This was a retrospective observational study including all adults with SARS-CoV-2 infection admitted to Hospital Universitario Marqués de Valdecilla from February to May 2020. Patients were stratified according to COVID-GRAM and CURB-65 scores as being at low-medium or high risk of critical illness. Univariate analysis, multivariate logistic regression models, receiver operating characteristic curve, and area under the curve (AUC) were calculated. RESULTS: A total of 523 patients were included (51.8% male, 48.2% female; mean age 65.63 years (standard deviation 17.89 years)), of whom 110 (21%) presented a critical illness (intensive care unit admission 10.3%, 30-day mortality 13.8%). According to the COVID-GRAM score, 122 (23.33%) patients were classified as high risk; 197 (37.7%) presented a CURB-65 score ≥2. A significantly greater proportion of patients with critical illness had a high COVID-GRAM score (64.5% vs 30.5%; P < 0.001). The COVID-GRAM score emerged as an independent predictor of critical illness (odds ratio 9.40, 95% confidence interval 5.51-16.04; P < 0.001), with an AUC of 0.779. A high COVID-GRAM score showed an AUC of 0.88 for the prediction of 30-day mortality, while a CURB-65 ≥2 showed an AUC of 0.83. CONCLUSIONS: The COVID-GRAM score may be a useful tool for evaluating the risk of critical illness in Caucasian patients with SARS-CoV-2 infection. The CURB-65 score could be considered as an alternative.


Assuntos
COVID-19 , Adulto , Idoso , Feminino , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , SARS-CoV-2 , Índice de Gravidade de Doença
12.
J Integr Plant Biol ; 63(2): 312-326, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33085192

RESUMO

Plants experience different abiotic/biotic stresses, which trigger their molecular machinery to cope with them. Besides general mechanisms prompted by many stresses, specific mechanisms have been introduced to optimize the response to individual threats. However, these key mechanisms are difficult to identify. Here, we introduce an in-depth species-specific transcriptomic analysis and conduct an extensive meta-analysis of the responses to related species to gain more knowledge about plant responses. The spider mite Tetranychus urticae was used as the individual species, several arthropod herbivores as the related species for meta-analysis, and Arabidopsis thaliana plants as the common host. The analysis of the transcriptomic data showed typical common responses to herbivory, such as jasmonate signaling or glucosinolate biosynthesis. Also, a specific set of genes likely involved in the particularities of the Arabidopsis-spider mite interaction was discovered. The new findings have determined a prominent role in this interaction of the jasmonate-induced pathways leading to the biosynthesis of anthocyanins and tocopherols. Therefore, tandem individual/general transcriptomic profiling has been revealed as an effective method to identify novel relevant processes and specificities in the plant response to environmental stresses.


Assuntos
Arabidopsis/genética , Arabidopsis/parasitologia , Artrópodes/fisiologia , Herbivoria/fisiologia , Transcriptoma/genética , Animais , Análise por Conglomerados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Redes Reguladoras de Genes , Metanálise como Assunto , Tetranychidae/fisiologia
13.
Rev Chil Anest ; 50(4): 593-597, 2021. ilus
Artigo em Espanhol | LILACS | ID: biblio-1526291

RESUMO

We present a series of four patients diagnosed with Spinal Muscular Atrophy (SMA), 2 type II, 2 type III, for placement of spinal nusinersen/Spinraza under general anesthesia with propofol. This new treatment can improve the quality of life of these patients. Its management represents a challenge for anesthesiologists as they try to provide not only adequate general anesthesia but containment to adolescent or young patients. In particular, patients that need to enter into the operating room several times a year.


Presentamos una serie de 4 pacientes con diagnóstico de atrofia muscular espinal (AME) 2 tipo II y 2 tipo III, para colocación de nusinersen/Spinraza raquídeo bajo anestesia general con propofol. Este nuevo tratamiento puede mejorar la calidad de vida de los pacientes. Su manejo representa un desafío para los anestesiólogos que intentamos brindar no solo una adecuada anestesia general sino contención a pacientes adolescentes o jóvenes que necesitan ingresar al quirófano varias veces al año.


Assuntos
Humanos , Masculino , Adolescente , Adulto , Oligonucleotídeos/administração & dosagem , Atrofia Muscular Espinal/tratamento farmacológico , Anestesia Geral , Injeções Espinhais
14.
Plants (Basel) ; 9(4)2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32272602

RESUMO

The molecular interactions between a pest and its host plant are the consequence of an evolutionary arms race based on the perception of the phytophagous arthropod by the plant and the different strategies adopted by the pest to overcome plant triggered defenses. The complexity and the different levels of these interactions make it difficult to get a wide knowledge of the whole process. Extensive research in model species is an accurate way to progressively move forward in this direction. The two-spotted spider mite, Tetranychus urticae Koch has become a model species for phytophagous mites due to the development of a great number of genetic tools and a high-quality genome sequence. This review is an update of the current state of the art in the molecular interactions between the generalist pest T. urticae and its host plants. The knowledge of the physical and chemical constitutive defenses of the plant and the mechanisms involved in the induction of plant defenses are summarized. The molecular events produced from plant perception to the synthesis of defense compounds are detailed, with a special focus on the key steps that are little or totally uncovered by previous research.

15.
Front Plant Sci ; 11: 620086, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33488661

RESUMO

Reactive nitrogen species (RNS), mainly nitric oxide (NO), are highly reactive molecules with a prominent role in plant response to numerous stresses including herbivores, although the information is still very limited. This perspective article compiles the current progress in determining the NO function, as either a signal molecule, a metabolic intermediate, or a toxic oxidative product, as well as the contribution of molecules associated with NO metabolic pathway in the generation of plant defenses against phytophagous arthropods, in particular to insects and acari.

16.
Front Plant Sci ; 10: 930, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31379907

RESUMO

The plant defense responses to pests results in the synchronized change of a complex network of interconnected genes and signaling pathways. An essential part of this process is mediated by the binding of transcription factors to the specific responsive cis-elements within in the promoters of phytophagous-responsive genes. In this work, it is reported the identification and characterization of a bidirectional promoter that simultaneously co-regulate two divergent genes, At5g10300 and At5g10290, upon arthropod feeding. Computational analysis identified the presence of cis-elements within the intergenic region between two loci, mainly from the DOF but also from the AP2/ERF, Golden 2-like and bHLH families. The function of the bidirectional promoter was analyzed using two enhanced variants of the GFP and CherryFP reporter genes, in both orientations, in transient tobacco and stably transformed Arabidopsis plants. Promoter activity was tested in response to feeding of Tetranychus urticae and Pieris brassicae, as well as wounding, flagellin and chitin treatments. Using RT-qPCR assays and confocal microscopy, it was shown that all treatments resulted in the induction of both reporter genes. Furthermore, our findings revealed the asymmetric character of the promoter with stronger activity in the forward than in the reverse orientation. This study provides an example of a bidirectional promoter with a strong potential to be used in plant biotechnology in pest control that requires stacking of the defense genes.

17.
Plant Physiol ; 179(4): 1298-1314, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30765478

RESUMO

Plant immunity depends on fast and specific transcriptional reprogramming triggered by the perception of biotic stresses. Numerous studies have been conducted to better understand the response of plants to the generalist herbivore two-spotted spider mite (Tetranychus urticae). However, how plants perceive mites and how this perception is translated into changes in gene expression are largely unknown. In this work, we identified a gene induced in Arabidopsis (Arabidopsis thaliana) upon spider mite attack that encodes a two-domain protein containing predicted lectin and Toll/Interleukin-1 receptor domains. The gene, previously named PP2-A5, belongs to the Phloem Protein2 family. Biotic assays showed that PP2-A5 confers tolerance to T. urticae Overexpression or knockout of PP2-A5 leads to transcriptional reprogramming that alters the balance of hormone accumulation and corresponding signaling pathways. The nucleocytoplasmic location of this protein supports a direct interaction with regulators of gene transcription, suggesting that the combination of two putative signaling domains in a single protein may provide a novel mechanism for regulating gene expression. Together, our results suggest that PP2-A5 improves the ability to defend against T. urticae by participating in the tight regulation of hormonal cross talk upon mite feeding. Further research is needed to determine the mechanism by which this two-domain protein functions and to clarify its molecular role in signaling following a spider mite attack.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Tetranychidae/fisiologia , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Feminino , Glucosinolatos/metabolismo , Herbivoria , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
18.
Front Plant Sci ; 9: 986, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30042779

RESUMO

Tetranychus urticae (two-spotted spider mite) is a striking example of polyphagy among herbivores with an extreme record of pesticide resistance and one of the most significant pests in agriculture. The T. urticae genome contains a large number of cysteine- and serine-proteases indicating their importance in the spider mite physiology. This work is focused on the potential role of the Kunitz trypsin inhibitor (KTI) family on plant defense responses against spider mites. The molecular characterization of two of these genes, AtKTI4 and AtKTI5, combined with feeding bioassays using T-DNA insertion lines for both genes was carried out. Spider mite performance assays showed that independent KTI silencing Arabidopsis lines conferred higher susceptibility to T. urticae than WT plants. Additionally, transient overexpression of these inhibitors in Nicotiana benthamiana demonstrated their ability to inhibit not only serine- but also cysteine-proteases, indicating the bifunctional inhibitory role against both types of enzymes. These inhibitory properties could be involved in the modulation of the proteases that participate in the hydrolysis of dietary proteins in the spider mite gut, as well as in other proteolytic processes.

19.
Sci Rep ; 8(1): 9432, 2018 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-29930298

RESUMO

Reactive oxygen species (ROS) are molecules that play a prominent role in plant response to numerous stresses, including plant interactions with herbivores. Previous findings indicate that Arabidopsis plants showed an increase in H2O2 accumulation after Tetranychus urticae infestation. Despite its importance, no information has been reported on the relationships between ROS-metabolizing systems and the spider mite-triggered plant-induced responses. In this work, four ROS-related genes that were differentially expressed between the resistant Bla-2 and the susceptible Kon Arabidopsis accessions were selected for the analysis. These genes encode proteins putatively involved in the generation (BBE22) and degradation (GPX7 and GSTU4) of H2O2, and in the degradation of ascorbate (AO). Overexpressing BBE22 and silencing GPX7, GSTU4 and AO resulted in higher leaf damage and better mite performance relative to the wild-type plants. Minor effects on H2O2 accumulation obscure major effects on the expression of genes related to ROS-metabolism and JA and SA signaling pathways, and on ROS-related enzymatic activities. In conclusion, the integration of ROS and ROS-related compounds and enzymes in the response of Arabidopsis to the spider mite T. urticae was confirmed. However, the complex network involved in ROS signaling makes difficult to predict the impact of a specific genetic manipulation.


Assuntos
Arabidopsis/metabolismo , Homeostase , Interações Hospedeiro-Parasita , Peróxido de Hidrogênio/metabolismo , Tetranychidae/patogenicidade , Animais , Arabidopsis/genética , Arabidopsis/parasitologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Peroxidases/genética , Peroxidases/metabolismo
20.
Int J Mol Sci ; 19(5)2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29751577

RESUMO

Plant⁻pest relationships involve complex processes encompassing a network of molecules, signals, and regulators for overcoming defenses they develop against each other. Phytophagous arthropods identify plants mainly as a source of food. In turn, plants develop a variety of strategies to avoid damage and survive. The success of plant defenses depends on rapid and specific recognition of the phytophagous threat. Subsequently, plants trigger a cascade of short-term responses that eventually result in the production of a wide range of compounds with defense properties. This review deals with the main features involved in the interaction between plants and phytophagous insects and acari, focusing on early responses from the plant side. A general landscape of the diverse strategies employed by plants within the first hours after pest perception to block the capability of phytophagous insects to develop mechanisms of resistance is presented, with the potential of providing alternatives for pest control.


Assuntos
Insetos/patogenicidade , Ácaros/patogenicidade , Plantas/parasitologia , Animais , Lectinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas/metabolismo
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