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Efforts are intensifying to identify bioactive microbial metabolites from biocontrol agents to manage plant pathogens in critical crops. This study examined both volatile organic compounds (VOCs) and non-volatile compounds from Metarhizium carneum and Lecanicillium uredinophilum strains for their antimicrobial effects against various phytopathogens and analyzed their exo-metabolomes. M. carneum VOCs inhibited four bacterial and eight fungal species by up to 45.45%, while L. uredinophilum VOCs inhibited five bacterial and eight fungal species by up to 50.91%. Additionally, n-BuOH extracts from both biocontrol agents effectively targeted three fungi and five bacteria. The exo-metabolomes of M. carneum and L. uredinophilum included 125 and 102 spectrometric features, respectively, primarily consisting of polyketides, alkaloids, lipids, organic aromatic compounds, terpenoids, and peptides. Our findings revealed a correlation between the phylogenetic relationships of M. carneum strains, their bioactivity patterns against phytopathogens, and their metabolomic profiles. Notably, some compounds detected in both fungi previously demonstrated biological activity against plant pathogens, enhancing their biocontrol potential. This study not only evidences the antimicrobial properties of diffusible compounds from M. carneum and L. uredinophilum, but also documents the antimicrobial potential of their VOCs for the first time, supporting their use in sustainable agricultural practices, reducing reliance on chemical inputs.

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Bell pepper plants are sensitive to environmental changes and are significantly affected by abiotic factors such as UV-B radiation and cold, which reduce their yield and production. Various approaches, including omics data integration, have been employed to understand the mechanisms by which this crop copes with abiotic stress. This study aimed to find metabolic changes in bell pepper stems caused by UV-B radiation and cold by integrating omic data. Proteome and metabolome profiles were generated using liquid chromatography coupled with mass spectrometry, and data integration was performed in the plant metabolic pathway database. The combined stress of UV-B and cold induced the accumulation of proteins related to photosynthesis, mitochondrial electron transport, and a response to a stimulus. Further, the production of flavonoids and their glycosides, as well as affecting carbon metabolism, tetrapyrrole, and scopolamine pathways, were identified. We have made the first metabolic regulatory network map showing how bell pepper stems respond to cold and UV-B stress. We did this by looking at changes in proteins and metabolites that help with respiration, photosynthesis, and the buildup of photoprotective and antioxidant compounds.

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Transcription factors in phytopathogenic fungi are key players due to their gene expression regulation leading to fungal growth and pathogenicity. The KilA-N family encompasses transcription factors unique to fungi, and the Bqt4 subfamily is included in it and is poorly understood in filamentous fungi. In this study, we evaluated the role in growth and pathogenesis of the homologous of Bqt4, FspTF, in Fusarium sp. isolated from the ambrosia beetle Xylosandrus morigerus through the characterization of a CRISPR/Cas9 edited strain in Fsptf. The phenotypic analysis revealed that TF65-6, the edited strain, modified its mycelia growth and conidia production, exhibited affectation in mycelia and culture pigmentation, and in the response to certain stress conditions. In addition, the plant infection process was compromised. Untargeted metabolomic and transcriptomic analysis, clearly showed that FspTF may regulate secondary metabolism, transmembrane transport, virulence, and diverse metabolic pathways such as lipid metabolism, and signal transduction. These data highlight for the first time the biological relevance of an orthologue of Bqt4 in Fusarium sp. associated with an ambrosia beetle.

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The antifungal and insecticidal activities of 34 extracts from 27 plant species were evaluated against fungal phytopathogens of the genus Fusarium and Xyleborus Scolytine ambrosia beetles involved in Fusarium dieback (FD) and laurel wilt (LW) diseases. Sixteen extracts caused mycelial growth inhibition (MGI) above 23 % at 2 mg mL-1 against F. solani, those from S. nudum and M. argyrophylla exhibited the highest MGI (57 % and 49 %, respectively). Thirteen extracts displayed significant antifungal activity against F. kuroshium, those from C. nocturnum and M. argyrophylla exhibited the highest MGI (100 % and 54.9 %, respectively). Additionally, ten plants extracts caused mortality in at least one of the beetle species tested, mainly from Solanaceae species. In the most active species, 39 phenolics were identified that may have contributed to their biological effects. This study is one of the first to report the potential of plant-derived natural products against the causative agents of FD and LW.

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Avocado (Persea americana Mill.) is a tree crop of great social and economic importance. However, the crop productivity is hindered by fast-spreading diseases, which calls for the search of new biocontrol alternatives to mitigate the impact of avocado phytopathogens. Our objectives were to evaluate the antimicrobial activity of diffusible and volatile organic compounds (VOCs) produced by two avocado rhizobacteria (Bacillus A8a and HA) against phytopathogens Fusarium solani, Fusarium kuroshium, and Phytophthora cinnamomi, and assess their plant growth promoting effect in Arabidopsis thaliana. We found that, in vitro, VOCs emitted by both bacterial strains inhibited mycelial growth of the tested pathogens by at least 20%. Identification of bacterial VOCs by gas chromatography coupled to mass spectrometry (GC-MS) showed a predominance of ketones, alcohols and nitrogenous compounds, previously reported for their antimicrobial activity. Bacterial organic extracts obtained with ethyl acetate significantly reduced mycelial growth of F. solani, F. kuroshium, and P. cinnamomi, the highest inhibition being displayed by those from strain A8a (32, 77, and 100% inhibition, respectively). Tentative identifications carried out by liquid chromatography coupled to accurate mass spectrometry of diffusible metabolites in the bacterial extracts, evidenced the presence of some polyketides such as macrolactins and difficidin, hybrid peptides including bacillaene, and non-ribosomal peptides such as bacilysin, which have also been described in Bacillus spp. for antimicrobial activities. The plant growth regulator indole-3-acetic acid was also identified in the bacterial extracts. In vitro assays showed that VOCs from strain HA and diffusible compounds from strain A8a modified root development and increased fresh weight of A. thaliana. These compounds differentially activated several hormonal signaling pathways involved in development and defense responses in A. thaliana, such as auxin, jasmonic acid (JA) and salicylic acid (SA); genetic analyses suggested that developmental stimulation of the root system architecture by strain A8a was mediated by the auxin signaling pathway. Furthermore, both strains were able to enhance plant growth and decreased the symptoms of Fusarium wilt in A. thaliana when soil-inoculated. Collectively, our results evidence the potential of these two rhizobacterial strains and their metabolites as biocontrol agents of avocado pathogens and as biofertilizers.

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Vanilla planifolia is an orchid of cultural and economic value. However, its cultivation in many tropical countries is threatened by water stress. In contrast, V. pompona is a species that is tolerant of prolonged periods of drought. Due to the need for plants' resistant to water stress, the use of hybrids of these two species is considered. Therefore, the objective of this study was to evaluate the morphological and physio-chemical responses of in vitro vanilla seedlings of the parental genotype V. planifolia, and the hybrids V. planifolia × V. pompona and V. pompona × V. planifolia, which were then exposed over five weeks to polyethylene glycol-induced water stress (-0.49 mPa). Stem and root length, relative growth rate, number of leaves and roots, stomatal conductance, specific leaf area, and leaf water content were determined. Metabolites potentially associated with the response to water stress were identified in leaves, through untargeted and targeted metabolomics. Both hybrids exhibited a smaller decrease in the morphophysiological responses compared to V. planifolia and exhibited an enrichment of metabolites such as carbohydrates, amino acids, purines, phenols, and organic acids. Hybrids of these two species are considered as a potential alternative to the traditional cultivation of vanilla to face drought in a global warming scenario.

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An Acinetobacter calcoaceticus UTMR2 strain was evaluated in tomatillo plants (Physalis ixocarpa Brot.) using a factorial design with different potassium doses (100, 75, 50 and 0% of the recommended dose). In addition to the agronomic parameters, an analysis of the physicochemical, antioxidant, and metabolomic properties of the fruit was performed. The application of the inoculant affected several parameters of the plant (chlorophyll, weight, and contents of several mineral elements) as well as of the fruit (yield, maturity index, FRAP antioxidant capacity, and contents of protein, fiber, and fat). A multivariate analysis was performed by means of a PCA and a heatmap, indicating that the inoculant induced a strong modulating activity in tomatillo plants for the evaluated parameters, with a remarkable effect at low K doses (0 and 50%). The inoculated treatment at 75% of the K dose resulted in similar plant and fruit characteristics to the fully fertilized control. On the other hand, the biofertilized treatment with no K addition resulted in the highest values in the plant and fruit parameters. In addition, from the metabolomics analysis of the fruits at 75% of the K dose, the up-regulation of 4,4″-bis(N-feruloyl)serotonin, salvianolic acid K, and chlorogenic acid was observed, which may have a role in anti-senescence and resistance mechanisms. In conclusion, the rhizobacterial strain had a positive effect on plant growth, nutritional quality, bioactive compounds, and antioxidant activity of tomatillo fruits at reduced doses of K fertilizer, which gives support for its consideration as an effective biofertilizer strain.

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Anastrepha spp. (Diptera: Tephritidae) infestations cause significant economic losses in commercial fruit production worldwide. However, some plants quickly counteract the insertion of eggs by females by generating neoplasia and hindering eclosion, as is the case for Persea americana Mill., cv. Hass (Hass avocados). We followed a combined transcriptomics/metabolomics approach to identify the molecular mechanisms triggered by Hass avocados to detect and react to the oviposition of the pestiferous Anastrepha ludens (Loew). We evaluated two conditions: fruit damaged using a sterile pin (pin) and fruit oviposited by A. ludens females (ovi). We evaluated both of the conditions in a time course experiment covering five sampling points: without treatment (day 0), 20 min after the treatment (day 1), and days 3, 6, and 9 after the treatment. We identified 288 differentially expressed genes related to the treatments. Oviposition (and possibly bacteria on the eggs' surface) induces a plant hypersensitive response (HR), triggering a chitin receptor, producing an oxidative burst, and synthesizing phytoalexins. We also observed a process of cell wall modification and polyphenols biosynthesis, which could lead to polymerization in the neoplastic tissue surrounding the eggs.

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The aim of this study was to explore the effect of capsaicin and particular phenolic compounds profile from cellulase assisted extracts of Habanero (Capsicum chinense) chili pepper seeds (CPS) on the concentration of cytokines (IL-2, IL-6, TNF-α, IL-1ß) in murine macrophages (RAW 264.7) stimulated with lipopolysaccharides (LPS). Capsaicin was quantified by HPLC-DAD, and the phenolic profile was determined by UPLC-MS-QqQ. Anti-inflammatory activity was evaluated by Mouse Cytokine/Chemokine Magnetic Bead Panel 96-well plate assay. Among the 15 different phenolics found in CPS extracts obtained at 120 or 150 min of maceration with 2,500 UI/L at 30 ºC or 45 ºC in a 1:15 (w:v) proportion, the most abundant was vanillic acid (7.97-12.66 µg/g). The extract obtained at 30 ºC and 120 min, showed similar effects than the observed for synthetic anti-inflammatory drugs indomethacin and dexamethasone, and capsaicin standard. Beyond capsaicin, salicylic, protocatechuic and trans-cinnamic acids as well as vanillin in CPS extracts were correlated with the anti-inflammatory effect. On the other hand, capsaicin and chlorogenic acid contents were potential immunostimulants whose concentration varied depending on the cellulase treatment time.

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Edible insects have become a promising food source because they are rich in protein, fatty acids, minerals, among others. In recent years, edible insects have been proposed to be used as innovative functional ingredients in terms of biological activity. The present study aimed to determine and compare biological activities of the extracts and hydrolysates obtained from early- and adult-stage edible grasshoppers Sphenarium purpurascens to evaluate their potential as a source of bioactive compounds. Proximal analyses showed that in adult grasshoppers (AGs), the percentage of protein (48.9% ± 1.2), crude fat (13.1% ± 0.09), and chitin (15.6% ± 0.81) was significantly higher than early grasshoppers (EGs) (42.2% ± 0.55, 9.35% ± 0.08, and 10.5% ± 0.15, respectively). Total phenolic compounds, 2,2-diphenyl-1-picrylhydrazyl (DPPH•), and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS•+) free radical scavenging were analyzed and reported. Enzymatic hydrolysis increased the concentration of total phenolic compounds and higher antioxidant capacity (up to 252.78 mM trolox). Once fractionated by ultrafiltration, the fraction that presented the highest antioxidant activity against DPPH• and ABTS•+ was that with molecules ≤ 10 kDa. Furthermore, the bioaccessibility of the samples was analyzed by in vitro protein digestion using a multienzymatic method, and a recovery index (RI) was reported. Extracts and hydrolysates were analyzed by UPLC-MS, and this allowed the identification of phenolic acids and flavonoids. The results obtained in this work suggest that the grasshopper can be used as a possible source of bioactive compounds that can be used in the food or pharmaceutical industry.