Low transition temperature mixture-based extraction of 14 pesticides from tomato samples and their high-performance liquid chromatography-tandem mass spectrometry analysis.

The extensive use of pesticides to control pest infestations has led to the development of analytical methods to determine pesticide residues in food matrices to prevent food exposure. However, most developed analytical methods do not consider impact on the environment in terms of the toxicity of the chemicals used and the amount of waste produced. An environmentally-friendly method, based on a miniaturized matrix solid-phase dispersion followed by high-performance liquid chromatography-tandem mass spectrometry, for the analysis of fourteen pesticides in tomatoes, was exploited. For the recovery of pesticides from tomato samples, a low transition temperature mixture (LTTM), containing choline chloride and sesamol 1:3 molar ratio, was employed. Extraction parameters like sample-to-dispersant ratio, extraction solvent volume and LTTM volume were optimized through a Box-Behnken design. The 1:4 sample-to-dispersant ratio, 900 µL of ethanol as extraction solvent and 50 µL of LTTM ensured the best result considering the pesticides' peak areas. The optimized analytical method was validated obtaining the following results: linearity range was between LOQ and 5 mg kg-1 with a minimum R2 of 0.9944 for tebufenozide, values in the range of 0.001-0.023 and 0.004-0.076 mg kg-1 were obtained for LOD and LOQ respectively, while peak areas intra-day and inter-day repeatability were maximum of 10.19 and 9.15 %, respectively. The analytical method was then applied to real samples studying whole, pulp and peel tomato pool. The analysis of whole and tomato pulp revealed the presence of seven and eight of the fourteen investigated pesticides, respectively. However, their concentration was lower than the limit of quantification. In tomato peel, five pesticides, namely dimethomorph, methoxyfenozide, pyraclostrobin, pyriproxyfen, and spiromesifen were quantified and their concentrations were below maximum residue levels.

Review Article title: Natural Compounds with Antimicrobial Activities in oral Candida infections during head and neck radiotherapy.

BACKGROUNDS: Oral colonization and infections are frequently observed in patients during and soon after radiation therapy (RT). Infective mucositis is a common side effect associated with cancer therapy, characterized by an inflammation of the oral mucous membranes with histological mucosal and submucosal changes. Ulcerative mucositis is responsible for significant pain, impairing the patient's nutritional intake and leading to local or systemic infections promoting mycosis due to several species of the genus Candida. According to international guidelines, treatment of candidiasis depends on the infection site and patient's condition. SUMMARY: Recently several studies have shown the protective role of natural compounds counteracting the activity of Candida biofilms. The aim of this review is to discuss the antimicrobial activities of natural compounds in fungal infections, especially Candida spp., during and soon after radiotherapy. Indeed new molecules are being discovered and assessed for their capacity to control Candida spp. growth and, probably in the future, will be used to treat oral candidiasis, overall, during radiotherapy. This review reports several preliminary data about preclinical and clinical evidence of their efficacy in the prevention and/or treatment of mucositis due to Radiotherapy with a brief description of the natural compounds with anti-Candida activities. KEY MESSAGES: The increase in the resistance to the available antifungal drugs related to Candida spp. infections increased as well as drug interactions, urging the development of innovative and more effective agents with antifungal action. Recent preclinical and clinical studies are identifying natural substances with anti-inflammatory and antifungal activity that could be tested in the prevention of candidiasis in patients undergoing radiotherapy. Further studies are needed to confirm these preliminary data.

Nutritional Approaches in Children with Overweight or Obesity and Hepatic Steatosis.

Childhood obesity is a global public health problem. Worldwide, 41 million children under 5 years and 340 million children and adolescents between 5 and 19 years are overweight. In addition, the recent COVID-19 epidemic has further amplified this social phenomenon. Obesity is a condition associated with various comorbidities, such as nonalcoholic fatty liver disease (NAFLD). The pathophysiology of NAFLD in obesity is intricate and involves the interaction and dysregulation of several mechanisms, such as insulin resistance, cytokine signaling, and alteration of the gut microbiota. NAFLD is defined as the presence of hepatic steatosis in more than 5% of hepatocytes, evaluated by histological analysis. It can evolve from hepatic steatosis to steatohepatitis, fibrosis, cirrhosis, hepatocellular carcinoma, and end-stage liver failure. Body weight reduction through lifestyle modification remains the first-line intervention for the management of pediatric NAFLD. Indeed, studies suggest that diets low in fat and sugar and conversely rich in dietary fibers promote the improvement of metabolic parameters. This review aims to evaluate the existing relationship between obesity and NAFLD in the pediatric population and to assess the dietary patterns and nutritional supplementations that can be recommended to prevent and manage obesity and its comorbidities.

Chemical Composition of Hazelnut Skin Food Waste and Protective Role against Advanced Glycation End-Products (AGEs) Damage in THP-1-Derived Macrophages.

Glycation and the accumulation of advanced glycation end-products (AGEs) are known to occur during aging, diabetes and neurodegenerative diseases. Increased glucose or methylglyoxal (MGO) levels in the blood of diabetic patients result in increased AGEs. A diet rich in bioactive food compounds, like polyphenols, has a protective effect. The aim of this work is to evaluate the capacity of hazelnut skin polyphenolic extract to protect THP-1-macrophages from damage induced by AGEs. The main polyphenolic subclass was identified and quantified by means of HPLC/MS and the Folin-Ciocalteu method. AGEs derived from incubation of bovine serum albumin (BSA) and MGO were characterized by fluorescence. Cell viability measurement was performed to evaluate the cytotoxic effect of the polyphenolic extract in macrophages. Reactive oxygen species' (ROS) production was assessed by the H2-DCF-DA assay, the inflammatory response by real-time PCR for gene expression, and the ELISA assay for protein quantification. We have shown that the polyphenolic extract protected cell viability from damage induced by AGEs. After treatment with AGEs, macrophages expressed high levels of pro-inflammatory cytokines and ROS, whereas in co-treatment with polyphenol extract there was a reduction in either case. Our study suggests that hazelnut skin polyphenol-rich extracts have positive effects and could be further investigated for nutraceutical applications.

"Nutripiatto": A tool for nutritional education. A survey to assess dietary habits in preschool children.

Childhood obesity is a global public health concern linked to metabolic and psychological comorbidities. There is growing evidence that children's lifestyle habits are shifting towards obesity, with dire consequences for their future well-being and healthcare costs. In this interventional study, we enrolled 115 children aged between 4-5 years (53% females and 47% males) and carried out nutrition education interventions to improve their dietary habits. We introduced "Nutripiatto", a visual plate icon and easy guide, which was used by the children during the study. We investigated the children's dietary habits using a Food Frequency Questionnaire at the beginning and end of the study, after one month of using "Nutripiatto". The results showed that the children significantly increased the portion sizes and frequency of vegetable consumption (P<0.001) and reduced the consumption of several junk foods such as French fries and crisps (P<0.001), reaching the recommended dietary allowances and frequency of consumption. Daily consumption of water also significantly increased, reaching the suggested amount of six glasses per day. Based on these results, "Nutripiatto" can be considered an effective visual guide and helpful tool to achieve small changes and empower families to make healthier food choices. It can also be considered an effective educational tool for nutritionists and healthcare professionals to improve children's dietary behavior.

The Arabidopsis thaliana Gulono-1,4 γ-lactone oxidase 2 (GULLO2) facilitates iron transport from endosperm into developing embryos and affects seed coat suberization.

Plants synthesize ascorbate (ASC) via the D-mannose/L-galactose pathway whereas animals produce ASC and H2O2via the UDP-glucose pathway, with Gulono-1,4 γ-lactone oxidases (GULLO) as the last step. A. thaliana has seven isoforms, GULLO1-7; previous in silico analysis suggested that GULLO2, mostly expressed in developing seeds, might be involved in iron (Fe) nutrition. We isolated atgullo2-1 and atgullo2-2 mutants, quantified ASC and H2O2 in developing siliques, Fe(III) reduction in immature embryos and seed coats. Surfaces of mature seed coats were analysed via atomic force and electron microscopies; suberin monomer and elemental compositions of mature seeds, including Fe, were profiled via chromatography and inductively coupled plasma-mass spectrometry. Lower levels of ASC and H2O2 in atgullo2 immature siliques are accompanied by an impaired Fe(III) reduction in seed coats and lower Fe content in embryos and seeds; atgullo2 seeds displayed reduced permeability and higher levels of C18:2 and C18:3 ω-hydroxyacids, the two predominant suberin monomers in A. thaliana seeds. We propose that GULLO2 contributes to ASC synthesis, for Fe(III) reduction into Fe(II). This step is critical for Fe transport from endosperm into developing embryos. We also show that alterations in GULLO2 activity affect suberin biosynthesis and accumulation in the seed coat.

Protective Role of Natural Compounds under Radiation-Induced Injury.

In recent years, evidence has shown the potential therapeutic effects of different natural compounds for the prevention and treatment of radiotherapy-induced mucositis (RIOM). RIOM represents one of the most frequent side effects associated with anti-neoplastic treatments affecting patients' quality of life and treatment response due to radiation therapy discontinuation. The innate radio-protective ability of natural products obtained from plants is in part due to the numerous antioxidants possessed as a part of their normal secondary metabolic processes. However, oxygen presence is a key point for radiation efficacy on cancer cells. The aim of this review is to describe the most recent evidence on radiation-induced injury and the emerging protective role of natural compounds in preventing and treating this specific damage without compromising treatment efficacy.

Plant Growth Monitoring: Design, Fabrication, and Feasibility Assessment of Wearable Sensors Based on Fiber Bragg Gratings.

Global climate change and exponential population growth pose a challenge to agricultural outputs. In this scenario, novel techniques have been proposed to improve plant growth and increase crop yields. Wearable sensors are emerging as promising tools for the non-invasive monitoring of plant physiological and microclimate parameters. Features of plant wearables, such as easy anchorage to different organs, compliance with natural surfaces, high flexibility, and biocompatibility, allow for the detection of growth without impacting the plant functions. This work proposed two wearable sensors based on fiber Bragg gratings (FBGs) within silicone matrices. The use of FBGs is motivated by their high sensitivity, multiplexing capacities, and chemical inertia. Firstly, we focused on the design and the fabrication of two plant wearables with different matrix shapes tailored to specific plant organs (i.e., tobacco stem and melon fruit). Then, we described the sensors' metrological properties to investigate the sensitivity to strain and the influence of environmental factors, such as temperature and humidity, on the sensors' performance. Finally, we performed experimental tests to preliminary assess the capability of the proposed sensors to monitor dimensional changes of plants in both laboratory and open field settings. The promising results will foster key actions to improve the use of this innovative technology in smart agriculture applications for increasing crop products quality, agricultural efficiency, and profits.

Comparison between In Vitro Chemical and Ex Vivo Biological Assays to Evaluate Antioxidant Capacity of Botanical Extracts.

The anti-oxidative activity of plant-derived extracts is well-known and confers health-promoting effects on functional foods and food supplements. Aim of this work is to evaluate the capability of two different assays to predict the real biological antioxidant efficiency. At this purpose, extracts from five different plant-derived matrices and commercial purified phytochemicals were analyzed for their anti-oxidative properties by using well-standardized in vitro chemical method (TEAC) and an ex vivo biological assay. The biological assay, a cellular membrane system obtained from erythrocytes of healthy volunteers, is based on the capability of phytochemicals treatment to prevent membrane lipid peroxidation under oxidative stress by UV-B radiation. Plant extracts naturally rich in phenols with different structure and purified phytochemicals showed different in vitro and ex vivo antioxidant capacities. A high correlation between phenolic contents of the plant-derived extracts and their ability to prevent oxidative injuries in a biological system was found, thus underlying the relevance of this class of metabolites in preventing oxidative stress. On the other hand, a low correlation between the antioxidant capacities was shown between in vitro and ex vivo antioxidant assay. Moreover, data presented in this work show how food complex matrices are more effective in preventing oxidative damages at biological level than pure phytochemicals, even if for these latter, the antioxidant activity was generally higher than that observed for food complex matrices.

Choline Chloride-Lactic Acid-Based NADES As an Extraction Medium in a Response Surface Methodology-Optimized Method for the Extraction of Phenolic Compounds from Hazelnut Skin.

Deep eutectic solvents (DESs) are promising green solvents for the extraction of compounds from food byproducts. Hazelnut (Corylus avellana L.) is one of the most commonly cultivated tree nuts worldwide. The skin represents one of the major byproducts of the hazelnut industry and accounts for 2.5% of the total hazelnut kernel weight. It is a rich source of phenolic compounds like flavan-3-ols, flavonols, dihydrochalcones, and phenolic acids. In this work, fifteen DESs based on choline chloride and betaine, with different compositions, were studied in order to test their phenolic compounds extraction efficiency through the determination of their total concentration via Folin-Ciocalteu assay. A qualitative analysis of extracted phenolic compounds was assessed by HPLC with UV and MS detection. Using the DES with the best extraction efficiency, a new ultrasound-assisted solid liquid extraction (UA-SLE) method was optimized though the response surface methodology (RSM), taking into account some extraction parameters. Efficient recovery of extracted phenolic compounds was achieved using a 35% water solution of choline chloride and lactic acid (molar ratio 1:2) as an extraction solvent, working at 80 °C and with a solid-to-solvent ratio of 1:25 gmL-1. The optimized conditions made it possible to recover 39% more phenolic compounds compared to a classic organic solvent.

Antioxidant and Antiglycation Effects of Polyphenol Compounds Extracted from Hazelnut Skin on Advanced Glycation End-Products (AGEs) Formation.

The advanced glycation end-products (AGEs) arise from non-enzymatic reactions of sugar with protein side chains, some of which are oxido-reductive in nature. Enhanced production of AGEs plays an important role in the pathogenesis of diabetic complications as well as in natural aging, renal failure, oxidative stress, and chronic inflammation. The aim of this work is to study antiglycation effects of polyphenol compounds extracted by hazelnut skin that represents an example of polyphenols-rich food industry by-product, on AGEs formation. AGEs derived from incubation of bovine serum albumin (BSA) and methylglyoxal (MGO) were characterized by fluorescence. The phenolics identification and total polyphenol content in hazelnut skin extracts were analyzed by HPLC-MS and the Folin-Ciocalteu method, respectively. Antioxidant efficacy was evaluated by monitoring total antioxidant activity to assess the ABTS radical scavenging activity of samples by TEAC assay and oxygen radical absorbance capacity (ORAC) assay, expressed as millimoles of Trolox equivalents per gram of sample. Data here presented suggest that phenolic compounds in hazelnut skin have an inhibitory effect on the BSA-AGEs model in vitro, and this effect is concentration-dependent. The putative role of the hazelnut skin antioxidative properties for hindering AGEs formation is also discussed. Because of AGEs contribution to the pathogenesis of several chronic diseases, foods enriched, or supplements containing natural bioactive molecules able to inhibit their production could be an interesting new strategy for supporting therapeutic approaches with a positive effect on human health.

Dispersive liquid-liquid microextraction using a low transition temperature mixture and liquid chromatography-mass spectrometry analysis of pesticides in urine samples.

Biomonitoring is a potent tool to control the health risk of people occupationally and non-occupationally exposed. The latest trend in bioanalytical chemistry is to develop quick, cheap, easy, safe and reliable green analytical procedures to analyse a large number of chemicals in easily accessible biomatrices such as urine. In this paper, a new dispersive liquid-liquid microextraction (DLLME) procedure, conceived to treat urine samples and based on the use of a low transition temperature mixture (LTTM), was developed and validated to analyse twenty pesticides commonly used in farm practises. The LTTM was composed of choline chloride and sesamol in molar ratio 1:3 (ChCl:Ses 1:3); its characterization via differential scanning calorimetry identified it as an LTTM and not as a deep eutectic solvent due to the occurrence of a glass transition at -71 °C. The prepared mixture was used as the extraction solvent in the DLLME procedure, while ethyl acetate as the dispersing solvent. The salting out effect (50 mg mL-1 of NaCl in a diluted urine sample) improved the separation phase and the analyte transfer to the extractant. Due to the high ionic strength and despite the density of ChCl:Ses 1:3 (1.25 g mL-1), the LTTM layer floated on the top of the sample solution after centrifugation. All extracts were analysed by high-performance liquid chromatography coupled to mass spectrometry. After optimization and validation of the whole method, lower limits of quantitation were in the range of 0.02 - 0.76 µg  L-1. Extraction recoveries spanned from 50 to 101 % depending on the spike level and analytes. Precision and accuracy ranges were 3-18% and 5-20%, respectively. The extraction procedure was also compared with other methods, showing to be advantageous for rapidity, simplicity, efficiency, and low cost. Finally, urine samples from ten volunteers were effectively analysed using the developed method.

Distribution of bioactives in entire mill chain from the drupe to the oil and wastes.

Industrial olive oil production generates large amounts of by-products, mainly pomaces and wastewaters. The latter, in particular, represents serious environmental problems requiring special treatments prior to disposal. While olive pomace finds use as alternative energy source, wastewaters still remain a task since it is not reusable, representing an additional cost on olive oil for its treatments. This study is a "comprehensive" overview on the distribution of bioactives in entire mill chain from the drupe to the oil and wastes. Identification was achieved through liquid chromatography coupled with mass spectrometry, spectrofotometric and fluorimetric detection. Phenols resulted the most abundant class of substances, with the highest hydroxytyrosol amounts in wastewater (214 mg/kg). Pomace contained a total of 304 mg/kg in terms of bioactives, thus representing a potential food supplement ingredient for functional foods with high nutritional values.

Blood orange (Citrus sinensis) as a rich source of nutraceuticals: investigation of bioactive compounds in different parts of the fruit by HPLC-PDA/MS.

This study is part of a wider investigation aimed to sustain the economical value of the by-products generated by the Citrus industry. In particular, the protected geographic indication (PGI) red orange of sicily (known as blood orange) has been analysed by HPLC and by the enzymatic AOAC method. All the by-products contain significant amounts of biologically active compounds (limonoids and flavonoids). The decanted pulps were the most abundant, with the highest amount of flavonoids (130 g/kg) and high amount of limonoids (5.5 g/kg). Seeds were the best source of limonoids with about 10 g/kg. Low amount of anthocyanins were found only in coarse pulps and waste water. The total, the insoluble and the soluble dietary fibre (TDF, IDF and SDF respectively) were also determined. The pulps resulted to be the best source of dietary fibre, based on the amount and on the best insoluble/soluble ratio.

Overexpression of ZePrx in Nicotiana tabacum Affects Lignin Biosynthesis Without Altering Redox Homeostasis.

Class III plant peroxidases (Prxs) are involved in the oxidative polymerization of lignins. Zinnia elegans Jacq. Basic peroxidase (ZePrx) has been previously characterized as capable of catalyzing this reaction in vitro and the role in lignin biosynthesis of several of its Arabidopsis thaliana homologous has been previously confirmed. In the present work, ZePrx was overexpressed in Nicotiana tabacum to further characterize its function in planta with particular attention to its involvement in lignin biosynthesis. Since Prxs are known to alter ROS levels by using them as electron acceptor or producing them in their catalytic activity, the impact of this overexpression in redox homeostasis was studied by analyzing the metabolites and enzymes of the ascorbate-glutathione cycle. In relation to the modification induced by ZePrx overexpression in lignin composition and cellular metabolism, the carbohydrate composition of the cell wall as well as overall gene expression through RNA-Seq were analyzed. The obtained results indicate that the overexpression of ZePrx caused an increase in syringyl lignin in cell wall stems, suggesting that ZePrx is relevant for the oxidation of sinapyl alcohol during lignin biosynthesis, coherently with its S-peroxidase nature. The increase in the glucose content of the cell wall and the reduction of the expression of several genes involved in secondary cell wall biosynthesis suggests the occurrence of a possible compensatory response to maintain cell wall properties. The perturbation of cellular redox homeostasis occurring as a consequence of ZePrx overexpression was kept under control by an increase in APX activity and a reduction in ascorbate redox state. In conclusion, our results confirm the role of ZePrx in lignin biosynthesis and highlight that its activity alters cellular pathways putatively aimed at maintaining redox homeostasis.

Choline-chloride and betaine-based deep eutectic solvents for green extraction of nutraceutical compounds from spent coffee ground.

Coffee beans contain several compounds which have shown nutraceutial properties; among them chlorogenic acids (CGAs) are the most studied, have shown nutraceutical properties. These molecules are also present in the waste by-product known as spent coffee grounds (SCG). SCG are generated during the production of coffee drink, whereby roasted, ground coffee beans are heat or steam treated. A HPLC-PDA/ESI-MS method has been developed for the analysis of the most representative CGAs in SCG samples using a green extraction approach based on deep eutectic solvents (DESs). We examined fifteen different DESs based on choline chloride and betaine as hydrogen bond acceptor in combination with different hydrogen bond donors being seven alcohols, two organic acids, one sugar and urea. Fifteen CGAs were detected, identified and quantified for the evaluation of extraction efficiency. A betaine-based DES with triethylene glycol (molar ratio 1:2) was the most effective one at extracting CGAs from SCG also compared to a conventional organic solvent. Thirty percent of water added to DES and sample to solvent ratio 1:15 (g/mL) were selected as the best extraction conditions. The chromatographic method was validated studying LOD, LOQ, retention time and peak area precision, and linearity range. Retention time and peak area repeatability were determined obtaining RSDs values below 0.63 % and 8.51 %, respectively. Inter-day precision was determined obtaining RSDs value below 0.58 % and 8.80 % for retention time and peak area, respectively.

Application of deep eutectic solvents for the extraction of phenolic compounds from extra-virgin olive oil.

A HPLC-DAD/ESI-MS method has been developed and validated for the analysis of the most representative phenolic compounds in extra-virgin olive oil (EVOO) samples using a green extraction approach based on deep eutectic solvents (DESs) at room temperature. We examined ten DESs based on choline chloride and betaine in combination with different hydrogen bond donors comprising six alcohols, two organic acids, and one urea. Five phenolic compounds, belonging to the classes of secoiridoids and phenolic alcohols, were selected for the evaluation of extraction efficiency. A betaine-based DES with glycerol (molar ratio 1:2) was found to be the most effective for extracting phenolic compounds as compared to a conventional solvent. The optimization of the extraction method involved the study of the quantity of water to be added to the DES and evaluation of the sample-to-solvent ratio optimal condition. Thirty percent of water added to DES and sample to solvent ratio 1:1 (w/v) were selected as the best conditions. The chromatographic method was validated by studying LOD, LOQ, intraday and interday retention time precision, and linearity range. Recovery values obtained spiking seed oil sample aliquots with standard compounds at 5 and 100 µg/g concentration were in the range between 75.2% and 98.7%.

Characterization of the polyphenolic fraction of pomegranate samples by comprehensive two-dimensional liquid chromatography coupled to mass spectrometry detection.

Punica granatum L., commonly known as pomegranate, is an ancient fruit widely consumed all over the world as fresh fruit or juice. In addition, it is extensively used in therapeutic formulas, cosmetics and food seasonings. The fruit is native to Afghanistan, Iran, China and the Indian sub-continent. The pomegranate market has steadily grown, presumably due to the increasing demand of health-conscious consumers for products with potential beneficial effects on human health, due to the synergistic presence of a unique and complex phytochemical composition that enclose anthocyanins, phenolic acids and hydrolysable tannins. Conventionally, for their analysis liquid chromatography is employed even though it can present some drawbacks in terms of resolving power. In this contribution, as a valuable alternative, comprehensive two-dimensional liquid chromatography with "shifted gradients" in the second dimension, was applied for the characterization of three pomegranate samples, leading to the identification of 37 different polyphenolic compounds.

Analysis of Redox Relationships in the Plant Cell Cycle: Determination of Ascorbate, Glutathione, and Poly(ADPribose)polymerase (PARP) in Plant Cell Cultures.

Reactive oxygen species (ROS) and low molecular weight antioxidants, such as glutathione and ascorbate, are powerful signalling molecules that participate in the control of plant growth and development, and modulate progression through the mitotic cell cycle. Enhanced ROS accumulation or low levels of ascorbate or glutathione cause the cell cycle to arrest and halt progression especially through the G1 checkpoint. Plant cell suspension cultures have proved to be particularly useful tools for the study of cell cycle regulation. Here we provide effective and accurate methods for the measurement of changes in the cellular ascorbate and glutathione pools and the activities of related enzymes such poly(ADP-ribose)polymerase (PARP) during mitosis and cell expansion, particularly in cell suspension cultures. These methods can be used in studies seeking to improve current understanding of the roles of redox controls on cell division and cell expansion.

Genetic buffering of cyclic AMP in Arabidopsis thaliana compromises the plant immune response triggered by an avirulent strain of Pseudomonas syringae pv. tomato.

Cyclic AMP plays important roles in different physiological processes, including plant defence responses. However, as little information is known on plant enzymes responsible for cAMP production/degradation, studies of cAMP functions have relied, to date, on non-specific pharmacological approaches. We therefore developed a more reliable approach, producing transgenic Arabidopsis thaliana lines overexpressing the 'cAMP-sponge' (cAS), a genetic tool that specifically buffers cAMP levels. In response to an avirulent strain of Pseudomonas syringae pv. tomato (PstAvrB), cAS plants showed a higher bacterial growth and a reduced hypersensitive cell death in comparison with wild-type (WT) plants. The low cAMP availability after pathogen infection delayed cytosolic calcium elevation, as well as hydrogen peroxide increase and induction of redox systems. The proteomic analysis, performed 24 h post-infection, indicated that a core of 49 proteins was modulated in both genotypes, while 16 and 42 proteins were uniquely modulated in WT and cAS lines, respectively. The involvement of these proteins in the impairment of defence response in cAS plants is discussed in this paper. Moreover, in silico analysis revealed that the promoter regions of the genes coding for proteins uniquely accumulating in WT plants shared the CGCG motif, a target of the calcium-calmodulin-binding transcription factor AtSR1 (Arabidopsis thaliana signal responsive1). Therefore, following pathogen perception, the low free cAMP content, altering timing and levels of defence signals, and likely acting in part through the mis-regulation of AtSR1 activity, affected the speed and strength of the immune response.