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Yellow pitahaya is a tropical fruit that has gained popularity in recent years. Natural elicitors are compounds that can stimulate the resistance and quality of fruits. The objective of this study was to evaluate the effects of natural elicitors, methyl salicylate (MeSa), methyl jasmonate (JaMe), salicylic acid (SA) and oxalic acid (OA) at concentrations of 0.1 mM (MeSa and JaMe) and 5 mM (SA and OA), applied to the yellow pitahaya fruits under greenhouse conditions. After full blossom, four applications were made with a frequency of 15 days. At the time of harvest and after storage, the following variables were evaluated: firmness (whole fruit), total soluble solids (TSS), total acidity (TA), phenolics and carotenoids (in the pulp), while phenolics, carotenoids, macronutrients and micronutrients were determined in the peel. The results showed MeSa advanced the fruit maturation, according to higher TSS, lower TA and firmness than MeJa-treated fruits, for which a delayed ripening process was shown. All treatments induced a higher polyphenolic concentration during storage. Regarding the alternative use of the peel as a by-product, the application of natural elicitors significantly increased the content of polyphenols, carotenoids, macronutrients and micronutrients in the peel, especially MeSa, which can be used as a bioactive compound in the food industry. In conclusion, the results indicate that natural elicitors can be an alternative to improve the quality and shelf life of yellow pitahaya fruits.

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Opuntia ficus-indica has always interacted with many phytophagous insects; two of them are Dactylopius coccus and D. opuntiae. Fine cochineal (D. coccus) is produced to extract carminic acid, and D. opuntiae, or wild cochineal, is an invasive pest of O. ficus-indica in more than 20 countries around the world. Despite the economic and environmental relevance of this cactus, D. opuntiae, and D. coccus, there are few studies that have explored volatile organic compounds (VOCs) derived from the plant-insect interaction. The aim of this work was to determine the VOCs produced by D. coccus and D. opuntiae and to identify different VOCs in cladodes infested by each Dactylopius species. The VOCs (essential oils) were obtained by hydrodistillation and identified by GC-MS. A total of 66 VOCs from both Dactylopius species were identified, and 125 from the Esmeralda and Rojo Pelón cultivars infested by D. coccus and D. opuntiae, respectively, were determined. Differential VOC production due to infestation by each Dactylopius species was also found. Some changes in methyl salicylate, terpenes such as linalool, or the alcohol p-vinylguaiacol were related to Dactylopius feeding on the cladodes of their respective cultivars. Changes in these VOCs and their probable role in plant defense mechanisms should receive more attention because this knowledge could improve D. coccus rearing or its inclusion in breeding programs for D. opuntiae control in regions where it is a key pest of O. ficus-indica.

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Obesity-related type II diabetes (diabesity) has increased global morbidity and mortality dramatically. Previously, the ancient drug salicylate demonstrated promise for the treatment of type II diabetes, but its clinical use was precluded due to high dose requirements. In this study, we present a nitroalkene derivative of salicylate, 5-(2-nitroethenyl)salicylic acid (SANA), a molecule with unprecedented beneficial effects in diet-induced obesity (DIO). SANA reduces DIO, liver steatosis and insulin resistance at doses up to 40 times lower than salicylate. Mechanistically, SANA stimulated mitochondrial respiration and increased creatine-dependent energy expenditure in adipose tissue. Indeed, depletion of creatine resulted in the loss of SANA action. Moreover, we found that SANA binds to creatine kinases CKMT1/2, and downregulation CKMT1 interferes with the effect of SANA in vivo. Together, these data demonstrate that SANA is a first-in-class activator of creatine-dependent energy expenditure and thermogenesis in adipose tissue and emerges as a candidate for the treatment of diabesity.

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The interaction between sodium salicylate (NaSal) and the two macrocycles 5,11,17,23-tetrakissulfonatomethylene-2,8,14,20-tetra(ethyl)resorcinarene (Na4EtRA) and ß-cyclodextrin (ß-CD) has been studied by the determination of ternary mutual diffusion coefficients, and spectroscopic and computational techniques. The results obtained by the Job method suggest that the complex formation is given in a 1:1 ratio for all systems. The mutual diffusion coefficients and the computational experiments have shown that the ß-CD-NaSal system presents an inclusion process, whereas the Na4EtRA-NaSal system forms an outer-side complex. This fact is also in line with the results obtained from the computational experiments, where the calculated solvation free energy has been found to be more negative for the Na4EtRA-NaSal complex because of the partial entry of the drug inside the Na4EtRA cavity.

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SiO2-SO3H, with a surface area of 115 m2/g and pore volume of 0.38 cm3g-1, and 1.32 mmol H+/g was used as a 20% w/w catalyst for the preparation of methyl salicylate (wintergreen oil or MS) from acetylsalicylic acid (ASA). A 94% conversion was achieved in a microwave reactor over 40 min at 120 °C in MeOH. The resulting crude product was purified by flash chromatography. The catalyst could be reused three times.

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High doses of salicylate induce tinnitus in humans and experimental animals. The Dorsal Cochlear Nucleus is implicated with the genesis of tinnitus, and increased activity in this nucleus is seen in animal models of tinnitus. Incubation of brainstem slices containing the DCN with millimolar salicylate reduces the spontaneous firing of glycinergic cartwheel neurons and glycinergic neurotransmission on fusiform neurons, the principal neuron of this nucleus. However, the mechanism of salicylate mediating this effect is not known. Recently, we have shown that KATP channels strongly modulate the spontaneous firing of cartwheel neurons. We tested if KATP channels could mediate the effects of salicylate on cartwheel neurons. Perfusion of 1.4 mM salicylate hyperpolarizes the membrane of cartwheel neurons and stops firing. Salicylate produces an outward current similar to the KATP current seen in quiet cartwheel neurons. Activation of this current is occluded by the KATP agonist diazoxide, which is produced by the opening of KATP channels. The antagonist of AMP-kinase (AMPK), dorsomorphim, inhibited salicylate effects, suggesting that they could be mediated by activation of this kinase. Still, the AMPK agonist, AICAR, did not reproduce salicylate effects but occluded them. Additionally, inhibiting mitochondrial ATP synthesis with the protonophore CCCP reproduced, albeit with less efficacy, and inhibited the effects of salicylate. We concluded that salicylate in millimolar concentrations opens KATP channels in DCN cartwheel neurons, inhibiting spontaneous firing of these neurons, probably by activating AMPK and reducing mitochondrial ATP synthesis.

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Citrus canker is a destructive disease caused by Xanthomonas citri subsp. citri, which affects all commercial sweet orange (Citrus sinensis [L.] Osbeck) cultivars. Salicylic acid (SA) and systemic-acquired resistance (SAR) have been demonstrated to have a crucial role in mediating plant defense responses against this phytopathogen. To induce SAR, SA is converted to methyl salicylate (MeSA) by an SA-dependent methyltransferase (SAMT) and translocated systemically to prime noninfected distal tissues. Here, we generated sweet orange transgenic plants (based on cvs. Hamlin and Valencia) overexpressing the SAMT gene from Citrus (CsSAMT) and evaluated their resistance to citrus canker. We obtained four independent transgenic lines and confirmed their significantly higher MeSA volatilization compared to wild-type controls. Plants overexpressing CsSAMT showed reduced symptoms of citrus canker and bacterial populations in all transgenic lines without compromising plant development. One representative transgenic line (V44SAMT) was used to evaluate resistance response in primary and secondary sites. Without inoculation, V44SAMT modulated CsSAMT, CsNPR1, CsNPR3, and CsWRKY22 expression, indicating that this plant is in a primed defense status. The results demonstrate that MeSA signaling prompts the plant to respond more efficiently to pathogen attacks and induces immune responses in transgenic plants at both primary and secondary infection sites.

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This study investigated the chemical constituents of Gaultheria procumbens essential oil and is the first to relate cytogenotoxicity with oxidative metabolism and antimicrobial activity. Chromatographic analysis of the essential oil showed methyl salicylate (99.96%) and linalool (0.04%) as the major compounds. The essential oil showed no signs of cytogenotoxicity at different concentrations (1.82 to 58.34 mg mL-1). Furthermore, G. procumbens essential oil and methyl salicylate were used to evaluate the minimal inhibitory concentrations (MIC) and minimal microbicidal concentrations (MMC). The results showed efficacy against several microorganisms, including Aeromonas caviae, Candida albicans, and Mycobacterium fortuitum with MIC values ranging from 1.82 to 3.64 mg mL-1 and MMC values ranging from 3.64 to 12.67 mg mL-1, which were confirmed by time-kill kinetics. Based on our results, the essential oil is a promising alternative to developing future formulations to treat infections caused by microorganisms.

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Abstract Herein the chemical constituents and the anti-pain properties of the essential oil from the stem bark of Casuarina equisetifolia L. (Casuarinaceae) grown in Nigeria were evaluated. The essential oil was obtained by hydrodistillation method in an all glass Clevenger-type apparatus, and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The hot plate method was used to determine the anti-nociceptive property whereas the anti-inflammatory activity was evaluated by carrageenan-induced and formalin experimental models. The pale-yellow essential oil was obtained in yield of 0.21% (v/w), calculated on a dry weight basis. The main constituents of the essential oil were methyl salicylate (30.4%), a-zingiberene (15.5%), (E)-anethole (9.5%), b-bisabolene (8.6%), b- sesquiphellandrene (6.9%), and ar-curcumene (6.2%). In the anti-nociceptive study, the rate of inhibition increases as the doses of essential oil increases with optimum activity at the 30th and 60th min for all tested doses. The essential oil displayed anti-nociceptive activity independently of reaction time at the highest tested dose (200 mg/kg). The essential oil of C. equisetifolia moderately reduced pain responses in early and late phases of the formalin test. The oil inhibited the paw licking in the neurogenic phase (60-63%) compared to the late phase of the formalin test. The carrageenan- induced oedema model revealed the suppression of inflammatory mediators within the 1st - 3rd h. Thus, C. equisetifolia essential oil displayed both anti-nociceptive and anti-inflammatory activities independent of the dose tested. The anti-inflammatory and anti-nociceptive activities of C. equisetifolia essential oil are herein reported for the first time

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The present study analyzed the volatile compounds emitted by Glycine max (cv. FT-Cristalina-RCH) soybean plants: healthy plants and plants damaged mechanically or by the Mexican soybean weevil Rhyssomatus nigerrimus. The SPME method was used to compare the volatile profile of soybean plants in four different conditions. The volatile profile of G. max plants infested by R. nigerrimus was qualitatively and quantitatively different from that of healthy and mechanically damaged plants. Emission of 59 compounds was detected in the four treatments. Of these compounds, 19 were identified by comparison of the Kovats index, mass spectrum and retention times with those of synthetic standards. An increase in concentration of the volatiles (Z)-3-hexenyl acetate and the compound 1-octen-3-ol was observed when the soybean plants were mechanically damaged. The compounds mostly produced by the soybean plant during infestation by male and female R. nigerrimus were 1-octen-3-ol, 6-methyl-5-hepten-2-one, (E)-beta-ocimene, salicylaldehyde, unknown 10, linalool, methyl salicylate, (Z)-8-dodecenyl acetate (ester 5), ketone 2 and geranyl acetone. Behavioral effects of the identified compounds during the insect-plant interaction and their conspecifics are discussed.(AU)

O presente estudo analisou os compostos voláteis emitidos pelas plantas de soja Glycine max (cv. FT-Cristalina-RCH): plantas e plantas sadias danificadas mecanicamente ou pelo gorgulho da soja mexicana Rhyssomatus nigerrimus. O método SPME foi utilizado para comparar o perfil volátil de plantas de soja em quatro diferentes condições. O perfil volátil das plantas de G. max infestadas por R. nigerrimus foi qualitativa e quantitativamente diferente do das plantas saudáveis e danificadas mecanicamente. Foi detectada, nos quatro tratamentos, emissão de 59 compostos, dos quais 19 foram identificados por comparação do índice de Kovats, espectro de massa e tempos de retenção com aqueles de padrões sintéticos. Um aumento na concentração dos voláteis acetato de (Z)-3-hexil e do composto 1-octeno-3-ol foi observado quando as plantas de soja foram mecanicamente danificadas. Os compostos produzidos principalmente pela planta de soja durante a infestação por R. nigerrimus macho e fêmea foram 1-octeno-3-ol, 6-metil-5-hepteno-2-ona, (E)-beta-ocimeno, salicilaldeído, desconhecido 10, linalol, salicilato de metila, acetato de (Z)-8-dodecenila (éster 5), cetona 2 e geranil acetona. Foram discutidos os efeitos comportamentais dos compostos identificados durante a interação inseto-planta e seus coespecíficos.(AU)

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Abstract The present study analyzed the volatile compounds emitted by Glycine max (cv. FT-Cristalina-RCH) soybean plants: healthy plants and plants damaged mechanically or by the Mexican soybean weevil Rhyssomatus nigerrimus. The SPME method was used to compare the volatile profile of soybean plants in four different conditions. The volatile profile of G. max plants infested by R. nigerrimus was qualitatively and quantitatively different from that of healthy and mechanically damaged plants. Emission of 59 compounds was detected in the four treatments. Of these compounds, 19 were identified by comparison of the Kovats index, mass spectrum and retention times with those of synthetic standards. An increase in concentration of the volatiles (Z)-3-hexenyl acetate and the compound 1-octen-3-ol was observed when the soybean plants were mechanically damaged. The compounds mostly produced by the soybean plant during infestation by male and female R. nigerrimus were 1-octen-3-ol, 6-methyl-5-hepten-2-one, (E)-β-ocimene, salicylaldehyde, unknown 10, linalool, methyl salicylate, (Z)-8-dodecenyl acetate (ester 5), ketone 2 and geranyl acetone. Behavioral effects of the identified compounds during the insect-plant interaction and their conspecifics are discussed.

Resumo O presente estudo analisou os compostos voláteis emitidos pelas plantas de soja Glycine max (cv. FT-Cristalina-RCH): plantas e plantas sadias danificadas mecanicamente ou pelo gorgulho da soja mexicana Rhyssomatus nigerrimus. O método SPME foi utilizado para comparar o perfil volátil de plantas de soja em quatro diferentes condições. O perfil volátil das plantas de G. max infestadas por R. nigerrimus foi qualitativa e quantitativamente diferente do das plantas saudáveis e danificadas mecanicamente. Foi detectada, nos quatro tratamentos, emissão de 59 compostos, dos quais 19 foram identificados por comparação do índice de Kovats, espectro de massa e tempos de retenção com aqueles de padrões sintéticos. Um aumento na concentração dos voláteis acetato de (Z)-3-hexil e do composto 1-octeno-3-ol foi observado quando as plantas de soja foram mecanicamente danificadas. Os compostos produzidos principalmente pela planta de soja durante a infestação por R. nigerrimus macho e fêmea foram 1-octeno-3-ol, 6-metil-5-hepteno-2-ona, (E)-β-ocimeno, salicilaldeído, desconhecido 10, linalol, salicilato de metila, acetato de (Z)-8-dodecenila (éster 5), cetona 2 e geranil acetona. Foram discutidos os efeitos comportamentais dos compostos identificados durante a interação inseto-planta e seus coespecíficos.

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Halomonas titanicae KHS3, isolated from a hydrocarbon-contaminated sea harbor in Argentina, is able to grow on aromatic hydrocarbons and displays chemotaxis toward those compounds. This behavior might contribute to the efficiency of its degradation capacity. Using high throughput screening, we identified two chemoreceptors (Htc1 and Htc2) that bind benzoate derivatives and other organic acids. Whereas Htc1 has a high affinity for benzoate (Kd 112 µM) and 2-hydroxybenzoate (Kd 83 µM), Htc2 binds 2-hydroxybenzoate with low affinity (Kd 3.25 mM), and also C3/C4 dicarboxylates. Both chemoreceptors are able to trigger a chemotactic response of E. coli cells to the specific ligands. A H. titanicae htc1 mutant has reduced chemotaxis toward benzoate, and is complemented upon expression of the corresponding receptor. Both chemoreceptors have a Cache-type sensor domain, double (Htc1) or single (Htc2), and their ability to bind aromatic compounds is reported here for the first time.

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MAIN CONCLUSION: Nicotiana tabacum overexpressing CrSAMT from Citrus reticulata increased production of MeSA, which works as an airborne signal in neighboring wild-type plants, inducing PR1 and increasing resistance to the pathogen Xylella fastidiosa. Xylella fastidiosa is one of the major threats to plant health worldwide, affecting yield in many crops. Despite many efforts, the development of highly productive resistant varieties has been challenging. In studying host plant resistance, the S-adenosyl-L-methionine: salicylic acid carboxyl methyltransferase gene (SAMT) from Citrus reticulata, a X. fastidiosa resistant species, was upregulated in response to pathogen infection. SAMT is involved with the catalysis and production of methyl salicylate (MeSA), an airborne signal responsible for triggering systemic acquired resistance. Here we used tobacco as a model system and generated transgenic plants overexpressing C. reticulata SAMT (CrSAMT). We performed an in silico structural characterization of CrSAMT and investigated its biotechnological potential in modulating the immune system in transgenic plants. The increase of MeSA production in transgenic lines was confirmed by gas chromatography (GC-MS). The transgenic lines showed upregulation of PR1, and their incubation with neighboring wild-type plants activated PR1 expression, indicating that MeSA worked as an airborne signal. In addition, transgenic plants showed significantly fewer symptoms when challenged with X. fastidiosa. Altogether, these data suggest that CrSAMT plays a role in host defense response and can be used in biotechnology approaches to confer resistance against X. fastidiosa.

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RESUMEN Se desarrolló y validó un método por cromatografía gaseosa para la cuantificación simultánea de mentol (MT), salicilato de metilo (SM), timol (TM) y ácido benzoico (AB) en una solución antiséptica bucal. Se utilizó una columna DB-WAX y dietilenglicol como estándar interno. Se determinó la linealidad en un intervalo de concentraciones de 64,00 a 96,00 µg/mL (MT), 80,00 a 120,00 µg/mL (SM), 96,00 a 144,00 µg/mL (TM) y 48,00 a 72,00 µg/mL (AB), obteniendo coeficientes de correlación superiores a 0,999, y coeficientes de variación de los factores de respuestas de 1,18, 1,95, 3,52 y 1,48%, respectivamente. Se establecieron límites de detección de 0,51; 1,14; 3,34 y 1,402 ng/mL para el MT, SM, TM y AB, respectivamente, mientras los límites de cuantificación fueron de 1,45, 3, 43, 9, 73 y 4, 36 ng/mL en cada caso. Los porcentajes de recuperación fueron de 100,03, 99, 31, 99, 92 y 100,12; con coeficientes de variación de 0,42, 0,79, 0,66 y 0,76% para cada caso. El método fue lineal, exacto, preciso y selectivo para la determinación de los analitos en el control de calidad.

SUMMARY A method was developed and validated by gas chromatography for the simultaneous quantification of menthol (MT), methyl salicylate (SM), thymol (TM) and benzoic acid (AB) in an oral antiseptic solution. A DB-WAX column and diethylene glycol was used as internal standard. Linearity was determined in a concentration range of 64.00 to 96.00 µg/mL (MT), 80.00 to 120.00 µg/mL (SM), 96.00 to 144.00 µg/mL (TM) and 48.00 to 72.00 µg/mL (AB) achieving correlation coefficients greater than 0.999, and coefficients of variation of the response factors of 1.18, 1.95, 3.52 and 1.48%, respectively. Detection limits were established: 0.51, 1.14, 3.34 and 1.402 ng/mL for MT, SM, TM, and AB, respectively, while the quantification limits were 1.45, 3.43, 9.73 and 4.36 ng/mL in each case. Recovery percentages were 100.03, 99.31, 99.92 and 100.12; with coefficients of variation of 0.42, 0.79, 0.66 and 0.76% for each case. The method was linear, accurate, precise, and selective for the determination of analytes in quality control.

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Abstract The present study analyzed the volatile compounds emitted by Glycine max (cv. FT-Cristalina-RCH) soybean plants: healthy plants and plants damaged mechanically or by the Mexican soybean weevil Rhyssomatus nigerrimus. The SPME method was used to compare the volatile profile of soybean plants in four different conditions. The volatile profile of G. max plants infested by R. nigerrimus was qualitatively and quantitatively different from that of healthy and mechanically damaged plants. Emission of 59 compounds was detected in the four treatments. Of these compounds, 19 were identified by comparison of the Kovats index, mass spectrum and retention times with those of synthetic standards. An increase in concentration of the volatiles (Z)-3-hexenyl acetate and the compound 1-octen-3-ol was observed when the soybean plants were mechanically damaged. The compounds mostly produced by the soybean plant during infestation by male and female R. nigerrimus were 1-octen-3-ol, 6-methyl-5-hepten-2-one, (E)--ocimene, salicylaldehyde, unknown 10, linalool, methyl salicylate, (Z)-8-dodecenyl acetate (ester 5), ketone 2 and geranyl acetone. Behavioral effects of the identified compounds during the insect-plant interaction and their conspecifics are discussed.

Resumo O presente estudo analisou os compostos voláteis emitidos pelas plantas de soja Glycine max (cv. FT-Cristalina-RCH): plantas e plantas sadias danificadas mecanicamente ou pelo gorgulho da soja mexicana Rhyssomatus nigerrimus. O método SPME foi utilizado para comparar o perfil volátil de plantas de soja em quatro diferentes condições. O perfil volátil das plantas de G. max infestadas por R. nigerrimus foi qualitativa e quantitativamente diferente do das plantas saudáveis e danificadas mecanicamente. Foi detectada, nos quatro tratamentos, emissão de 59 compostos, dos quais 19 foram identificados por comparação do índice de Kovats, espectro de massa e tempos de retenção com aqueles de padrões sintéticos. Um aumento na concentração dos voláteis acetato de (Z)-3-hexil e do composto 1-octeno-3-ol foi observado quando as plantas de soja foram mecanicamente danificadas. Os compostos produzidos principalmente pela planta de soja durante a infestação por R. nigerrimus macho e fêmea foram 1-octeno-3-ol, 6-metil-5-hepteno-2-ona, (E)--ocimeno, salicilaldeído, desconhecido 10, linalol, salicilato de metila, acetato de (Z)-8-dodecenila (éster 5), cetona 2 e geranil acetona. Foram discutidos os efeitos comportamentais dos compostos identificados durante a interação inseto-planta e seus coespecíficos.

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HYPOTHESIS: When tetradecyltrimethylammonium bromide, TTAB, is added to aqueous solution of sodium salicylate, NaSal, the threading of the aromatic anion into the micellar palisade leads to the formation of wormlike micelles. Based on the calorimetric titration of NaSal with TTAB, and on the lifetime of fluorescence of salicylate, we propose that the aggregation of the two components directly leads to the formation of wormlike micelles, without any pre-aggregation. EXPERIMENTS: By using an isothermal titration calorimeter, aliquots of TTAB were added to a dilute solution of NaSal. The energy involved in each addition was then integrated and the variation of enthalpy was determined. In the same range of concentrations and molar ratios, the surface tensiometry and time-resolved emission spectroscopy experiments were performed. FINDINGS: A very characteristic calorimetric signal associated with wormlike micelle formation was obtained, being the enthalpy variation of this process, ΔWLMH2980 < 0. When 1.2 mmol L-1 of NaSal is titrated with 11.0 mmol L-1 of TTAB at 298.15 K, ΔfH2980 = -10.31 kJ per mol of injectant. By adding TTAB to NaSal solution, two fluorescence lifetimes of salicylate were observed solely after wormlike micelle being formed. The correspondent lifetime values of 4.0 ns and 7.2 ns are respectively associated with the free and associated species of salicylate. The new results demonstrated that wormlike micelles are the first aggregate formed when TTAB is added to salicylate. This aspect is relevant for understanding the mechanism of wormlike micelles formation.

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Salicylate hydroxylase (NahG) is a flavin-dependent monooxygenase that catalyzes the decarboxylative hydroxylation of salicylate into catechol in the naphthalene degradation pathway in Pseudomonas putida G7. We explored the mechanism of action of this enzyme in detail using a combination of structural and biophysical methods. NahG shares many structural and mechanistic features with other versatile flavin-dependent monooxygenases, with potential biocatalytic applications. The crystal structure at 2.0 Šresolution for the apo form of NahG adds a new snapshot preceding the FAD binding in flavin-dependent monooxygenases. The kcat/Km for the salicylate reaction catalyzed by the holo form is >105 M-1 s-1 at pH 8.5 and 25 °C. Hammett plots for Km and kcat using substituted salicylates indicate change in rate-limiting step. Electron-donating groups favor the hydroxylation of salicylate by a peroxyflavin to yield a Wheland-like intermediate, whereas the decarboxylation of this intermediate is faster for electron-withdrawing groups. The mechanism is supported by structural data and kinetic studies at different pHs. The salicylate carboxyl group lies near a hydrophobic region that aids decarboxylation. A conserved histidine residue is proposed to assist the reaction by general base/general acid catalysis.

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Salicylate intoxication is a cause of tinnitus in humans and it is often used to produce tinnitus-like perception in animal models. Here, we assess whether salicylate induces anxiety-like electrophysiological and behavioral signs. Using microwire electrode arrays, we recorded local field potential in the ventral and, in some experiments dorsal hippocampus, in an open field arena 1 hr after salicylate (300 mg/kg) injection. We found that animals treated with salicylate moved dramatically less than saline treated animals. Salicylate-treated animals showed a strong 4-6 Hz (type 2) oscillation in the ventral hippocampus (with smaller peaks in dorsal hippocampus electrodes). Coherence in the 4-6 Hz-theta band was low in the ventral and dorsal hippocampus when compared to movement-related theta coherence (7-10 Hz). Moreover, movement related theta oscillation frequency decreased and its dependency on running speed was abolished. Our results suggest that salicylate-induced theta is mostly restricted to the ventral hippocampus. Slow theta has been classically associated to anxiety-like behaviors. Here, we show that salicylate application can consistently generate low frequency theta in the ventral hippocampus. Tinnitus and anxiety show strong comorbidity and the increase in ventral hippocampus low frequency theta could be part of this association.

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Thysanoptera-induced galls commonly culminate in simple folding or rolling leaf gall morphotypes. Most of these galls are induced by members of the suborder Tubulifera, with only a few species of the suborder Terebrantia being reported as gall inducers. The Terebrantia, as most of the gall inducers, manipulates the host plant cellular communication system, and induces anatomical and biochemical changes in its host plant. In an effort to keep its homeostasis, the host plant reacts to the stimuli of the galling insect and triggers chemical signaling processes. In contrast to free-living herbivores, the signaling processes involving galling herbivores and their host plants are practically unknown. Current investigation was performed into two steps: first, we set the structural profile of non-galled and galled leaves, and looked forward to find potential alterations due to gall induction by an undescribed species of Nexothrips (suborder Terebrantia) on Myrcia splendens. Once oil glands had been altered in size and number, the second step was the investigation of the chemical profile of three tissue samples: (1) non-galled leaves of a control individual, (2) non-galled leaves of galled plants, and (3) galls. This third sample was divided into two groups: (3.1) galls from which the inducing thrips were manually removed and (3.2) galls macerated with the inducing thrips inside. The chemical profile was performed by gas chromatography/ mass spectrometric detector after headspace solid-phase extraction. The galling activity of the Nexothrips sp. on M. splendens culminates in mesophyll compactness interspersed to diminutive hypersensitive spots, development of air cavities, and the increase in size and number of the secretory glands. Seventy-two compounds were completely identified in the volatile profile of the three samples, from which, sesquiterpenes and aldehydes, pertaining to the "green leaf volatile" (GLVs) class, are the most abundant. The rare event of gall induction by a Terebrantia revealed discrete alterations toward leaf rolling, and indicated quantitative differences related to the plant bioactivity manipulated by the galling thrips. Also, the content of methyl salicylate has varied and has been considered a potential biomarker of plant resistance stimulated as a long-distance effect on M. splendens individuals.

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BACKGROUND: Whether tactics to manipulate natural enemies in agro-ecosystems enhance their ecosystem function and services remains debatable. We conducted field experiments in 2015-2016 to test the hypothesis that attraction of natural enemies to herbivore-induced plant volatiles (HIPVs), alone or in combination with companion plants, increases crop productivity. Our treatments consisted of bean plants alone or baited with methyl salicylate (MeSA; an HIPV), or combined with coriander (a companion plant), or with both MeSA and coriander. Numbers of arthropods were visually sampled in each treatment. Sentinel aphids were used to measure ecosystem function (i.e. predation). Plant damage and biomass, and the number and weight of pods and seeds, were measured as a proxy for ecosystem services. RESULTS: MeSA and coriander, when alone or combined, increased the abundance of insect predators from six families, reduced herbivore (e.g. spider mite and thrips) populations, and increased aphid predation. MeSA and coriander also reduced damage by spider mites. MeSA with or without coriander did not, however, increase crop biomass or any yield parameters. CONCLUSIONS: MeSA alone or combined with coriander attracted different predator communities, altered pest communities, and reduced damage; however, these results did not cascade down to improve crop productivity. © 2018 Society of Chemical Industry.