Search Results (754)

Passion fruit (Passiflora edulis) quality is defined by integrated sensory and nutritional traits, including sugar–acid balance, volatile organic compounds (VOCs), pigment-related attributes, and bioactive compounds such as ascorbic acid and phenolics. These traits emerge from coordinated regulation of carbon allocation, mineral nutrition, ripening metabolism, and stress- and defense-related signaling pathways, which are strongly modulated by environmental conditions. Sustainable biological inputs are increasingly explored as tools to influence these regulatory networks; however, evidence linking such interventions to reproducible fruit quality outcomes in Passiflora remains fragmented. This review first synthesizes current knowledge on the physiological, biochemical, and molecular mechanisms underlying passion fruit quality formation and maintenance, and then discusses how biofertilizers; microbial inoculants (including plant growth-promoting rhizobacteria—PGPR and arbuscular mycorrhizal fungi—AMF); fungal-derived elicitors such as chitosan and chitooligosaccharides; and complementary postharvest biological strategies may modulate these processes. Emphasis is placed on traits beyond yield, including sugar–acid balance, aroma and VOC profiles, color, nutritional quality, texture, and shelf life. By integrating genomics, transcriptomics, metabolomics, proteomics, and microbiome-based evidence, we examine how environmental modulation and key signaling pathways intersect with metabolic networks underlying fruit quality. Available studies indicate that responses to biological inputs are context-dependent and often non-linear. Key knowledge gaps and priorities for mechanism-informed sustainable management of passion fruit quality are identified. Full article

Proteomic research in the genus Vitis has progressed from early biochemical studies of soluble proteins to high-resolution, quantitative analyses encompassing all major organs and derived products. This review provides a comprehensive synthesis of advances in grapevine and wine proteomics. In leaves, studies have revealed extensive remodeling of photosynthetic, antioxidant, and defense pathways under biotic (e.g., Plasmopara viticola, Erysiphe necator, Xylella fastidiosa, Candidatus Phytoplasma vitis) and abiotic stresses (drought, salinity, heat, light). Bud proteomics elucidated hormonal regulation and mechanisms of dormancy release, while root studies identified nitrate-dependent metabolic shifts and adaptive protein networks. Cell culture models enabled controlled investigation of elicitor responses, stilbene biosynthesis, and temperature-induced proteome changes. In berries, proteomics clarified developmental transitions from fruit set to ripening, emphasizing proteins related to secondary metabolism, vacuolar transport, and stress tolerance. Comparative analyses across cultivars and environments identified biomarkers linked to aroma, color, and texture. The wine proteome revealed selective persistence of grape-derived proteins (e.g., thaumatin-like proteins, chitinases) and yeast peptides influencing stability and sensory properties, while Botrytis cinerea infection significantly alters this balance by degrading PR proteins and introducing fungal enzymes. Altogether, the Vitis proteome emerges as a dynamic, multifunctional system crucial for understanding plant adaptation, enological quality, and biomarker discovery. Full article

Butterflies locate host sites using plant volatiles, while larval frass cues induce avoidance. This study investigated the olfactory responses of adult Papilio polytes to nine shared plant and frass volatiles across 1 × 10³ to 1 × 10⁶ ng load doses using electroantennography (EAG) and Y-tube olfactometer assays. EAG responses were significantly influenced by chemical composition, dose, and sex, as well as all their interactions. In contrast, behavioral choices were significantly driven only by chemical composition and its interaction with dose. Although females exhibited higher peripheral sensitivity than males, this physiological sexual dimorphism did not result in significant behavioral differences. Linalool, citronellal, and geraniol were identified as the most potent elicitors. While their single forms and binary blends elicited attraction or neutrality, the ternary mixture significantly repelled both sexes. These results demonstrate that VOC blend composition determines the direction of behavioral responses, with linalool playing a pivotal role in the transition from attraction to avoidance. These findings highlight the importance of shared plant–frass VOCs in host selection by oligophagous insects and provide a foundation for manipulating P. polytes behavior. Full article

Fruit anthocyanins are primary determinants of color, sensory quality, and nutritional value in grapes; however, their endogenous biosynthesis is governed by complex interactions among genetic, environmental, agronomic, and postharvest factors. This review elaborates recent advances in physiology and molecular biology to clarify the biosynthetic mechanisms in grapes, including the coordinated action of structural enzymes, MYB–bHLH–WD40 regulatory complexes, hormone-mediated signaling pathways, and vacuolar transport processes. Key environmental factors, such as temperature fluctuations, light exposure, water availability, and soil properties, regulate these networks, contributing to significant variation in pigmentation profiles across cultivars and growing regions. Strategic agronomic practices, including canopy management, regulated deficit irrigation, balanced nutrient management, and temperature-mitigation techniques, further influence pigmentation by modifying the microclimate of the fruit zone during development. Based on these mechanistic insights, this review evaluates targeted strategies for enhancing anthocyanin accumulation, highlighting recent progress in genetic improvement through CRISPR/Cas genome editing, transgenic approaches, and marker-assisted selection (MAS), which enable precise modulation of biosynthetic and regulatory genes. Complementary postharvest interventions, such as optimized cold storage, modified-atmosphere packaging, hormonal elicitors, and controlled oxidative technologies, provide additional opportunities to maintain or enhance pigment stability after harvest. Collectively, these advances establish a comprehensive framework linking molecular regulation with practical vineyard, breeding, and postharvest strategies, offering an integrated pathway to improve anthocyanin consistency, berry quality, and the phenolic characteristics of grape-derived products. Full article

Gluten allergy is linked to high risk of anaphylaxis. The relative allergenicity of glutens (alcohol-soluble gliadin and acid-soluble glutenin) from the three commercially grown wheat species (diploid Triticum monococcum, tetraploid Triticum durum, hexaploid Triticum aestivum) is unknown. A comparative gluten allergenicity map (CGAM) from these species will enable the identification of potentially hyper-/hypo-/iso-allergenic species/varieties of wheat as well as the determination of substantial equivalence of genetically engineered (GE) or other novel wheat lines. Here, using a recently described novel mouse model, we tested the hypothesis that the three different wheat species will exhibit natural variation in their gluten allergenicity. Groups of Balb/c mice were transdermally sensitized to alcohol-soluble or acid-soluble gluten extracts followed by elicitation of systemic anaphylaxis. Initial studies were performed to validate the model for glutens from the three wheat species. Both glutens from all three wheat species elicited robust specific IgE responses, as well as systemic anaphylaxis. However, comparative mapping analysis revealed differences in capacity to elicit specific IgE among the three wheat species with T. aestivum being the most potent in both gluten extracts. Hypothermic shock response analysis revealed that the three species elicited similar kinetics and intensity of anaphylaxis. Nevertheless, when analyzing mucosal mast cell response, it was revealed that the glutens from T. aestivum emerged as the most potent elicitor. Collectively, these results yield the first CGAM that may be utilized for preclinical testing of the allergenic potential of glutens from novel (e.g., GE) wheats and processed wheat products against existing wheat glutens. Full article

Phytopathogenic diseases are a major limiting factor in agricultural production. Therefore, scientific research continues to focus on developing effective techniques to mitigate their impact on crop productivity. Seaweed extracts, used as nutritional supplements, organic fertilizers, or bio-pesticides, have demonstrated their ability to enhance plant growth, increase yield, and alleviate the effects of abiotic stress. This study aimed to evaluate the effect of the aqueous extract of Bifurcaria bifurcata, collected from the Atlantic coast of Sidi Bouzid (El Jadida, Morocco), on the growth of Solanum tuberosum L., as well as its bactericidal activity against soft rot caused by Dickeya dadantii. The chemical Characterization revealed that Bifurcaria bifurcata aqueous extract is rich in polar and hydrophilic functional groups. In addition, this extract is particularly rich in phenolic metabolites, particularly phenolic acids, such as p-coumaric acid, ferulic acid, vanillic acid, and caffeic acid, which are known for their potential antimicrobial mechanisms. However, the treatment with 4 g/L extract resulted in a significant reduction in disease symptoms (>60%) and enhanced plant growth parameters, including 21% increase in plant height and 33% increase in leaf number. POX activity increased 6-fold (from 0.12 to 0.7 µmol/min/mg protein), indicating successful elicitation of plant defense mechanisms. The Bifurcaria bifurcata extract could act as novel activators of plant defense mechanisms and serve as potential alternatives to chemical pesticides. Full article

Climate change-induced abiotic stress, particularly heat and drought during olive oil accumulation, significantly threatens the productivity and oil quality of olive trees (Olea europaea L.). This study investigated the efficacy of pre-harvest elicitation using the biostimulants harpin and chitosan (both as commercially available products) under summer conditions in Greece, in commercially productive rainfed groves of cv. ‘Megaritiki’. Multivariate analysis (PCA and factor analysis) revealed that pre-harvest application of these elicitors successfully balanced the trade-off between oil yield and quality. Both harpin and chitosan maintained hydrolytic (free acidity—0.25 and 0.29 g oleic acid 100 g⁻¹, respectively, compared to 0.56 g oleic acid 100 g⁻¹ in the control) and primary oxidative markers (peroxides—4.16 and 4.16 meq O₂ kg⁻¹, respectively, compared to 5.20 meq O₂ kg⁻¹ in the control) at exceptionally low levels compared to untreated trees. The treatments induced a distinctive metabolic shift regarding volatile compounds governed by the lipoxygenase (LOX) pathway. Harpin application was strongly associated with complex floral and fruity volatile compounds (2-hexen-1-ol and trans-2-hexenal) and a high α-tocopherol concentration (38.58 mg kg⁻¹ compared to 23.12 mg kg⁻¹ in the control), suggesting an enhanced physiological response in favor of oil quality attributes. Conversely, chitosan elevated the oxidative stability of the oil by increasing total phenol concentration (by almost 97% compared to the control) and prioritizing the accumulation of the stable monounsaturated fatty acids (oleic acid—increased by 12.5% compared to the control) over polyunsaturated ones (linoleic acid), while endowing the oil with desirable “green freshness” aromas (cis-3-hexenal). These results demonstrate that elicitation with harpin and chitosan is a potent tool for sustainably enhancing extra virgin olive oil quality under rainfed conditions in Greece, steering fruit metabolism toward a premium nutraceutical and sensory profile and enhancing the functional properties of the oil (phenol content, antioxidant capacity, monounsaturated fatty acids, α-tocopherol and squalene). Full article

While L-tryptophan is a precursor of plant growth regulators, its effects on secondary metabolism, amino acid profile and cell wall organization in flax callus remain underexplored. This study aimed to optimize flax callus shaken cultures and evaluate the impact of L-tryptophan (0.1 mM and 1 mM) on structural properties of plant cell walls in tested callus using Fourier transform infrared spectroscopy. The impact of L-tryptophan on callus proliferation and metabolism was also determined, because amino acids (among them L-tryptophan) can promote the growth of callus. The results showed that 1 mM L-tryptophan is an effective elicitor, which stimulates flax callus to accumulate larger amounts of bioactive compounds, especially carotenoids and polyphenols, than control callus cultured without L-tryptophan. A lower concentration of L-tryptophan (0.1 mM) slightly improved the level of determined secondary metabolites (except flavonoids). The effect of L-tryptophan on polymers in plant cell walls was investigated. The data confirm that the plant cell wall is a dynamic structure, capable of remodelling in response to growth conditions and external agents. L-tryptophan (0.1 and 1 mM) reduced cellulose levels and induced structural changes in cellulose compared to the untreated control. The structural analyses also suggested a decrease in lignin level and increase in pectin amounts in flax callus after tryptophan addition in comparison to control callus. The results may reflect the relationship between tryptophan and auxins (which are derived from tryptophan) and confirm the role of these metabolites in shaping the structure of the plant cell wall. In fact, an increase in tryptophan level was confirmed in flax callus in tested experimental conditions (supplementation of cultures with both doses of L-tryptophan). These findings have practical significance, because L-tryptophan is also used as a fertilizer or component of fertilizers in plant cultivation. Full article

Fresh figs are characterised by high perishability, leading to a limited postharvest shelf life. Consequently, preharvest elicitor application strategies have been explored to enhance their quality and storability. During the 2022 and 2023 seasons, figs (cv. Calabacita) grown under high-density conditions were treated with oxalic acid (OA; 1 and 2 mM), melatonin (MEL; 0.1 and 0.5 mM), and γ-aminobutyric acid (GABA; 10 and 50 mM) through foliar sprays applied two or three times. Fruits were harvested at commercial maturity and analysed immediately after harvest. Physicochemical and bioactive parameters were determined. Analysis of variance was used to assess treatment effects, and t-tests were used to evaluate differences in the number of applications and between seasons. Significant seasonal effects were observed, whereas no cumulative effect from repeated applications was detected. OA at 2 mM increased fruit weight (37.9 g) and size (42.5 mm) and delayed ripening. MEL treatments enhanced sugar accumulation (100.1 g kg⁻¹ and 96 g kg⁻¹ of glucose and fructose, respectively), while GABA treatments were associated with a more advanced maturity stage. Notably, OA (2 mM), MEL (0.5 mM), and GABA (50 mM) significantly increased enzymatic antioxidant activity by an average of 24% and non-enzymatic antioxidant capacity by around 17% in general terms. These results indicate that preharvest elicitor application is a promising and eco-friendly approach to improve the nutritional value and overall quality of fresh figs. Full article

The purpose of this study was to assess the effectiveness of two nanostructures (MgO and Zn/MgO) against Sclerotinia sclerotiorum, which causes white mold disease in peas, as direct antifungal agents or resistance inducers in pea plants. The direct antifungal activity of these nanostructures was evaluated by assessing their ability to inhibit S. sclerotiorum growth in vitro and reduce white mold severity in the greenhouse. The induction of resistance in pea plants was examined by assessing the expression of three defense-related genes using quantitative real-time PCR and measuring the phenolic compounds content in treated pea plants relative to untreated controls. The effect of the tested control agents on the growth and yield of pea plants was investigated. In comparison to the untreated control, S. sclerotiorum growth was markedly suppressed following treatment with the investigated compounds. The complete suppression (100%) of S. sclerotiorum growth was achieved with concentration levels of 100 mg/L for both MgO and Zn/MgO nanostructures. In greenhouse conditions, pea plants treated with the investigated chemicals showed a considerable reduction in the severity of white mold disease when compared to the untreated control plants. The transcript levels of 12-oxophytodienoate reductase 11 (OPR1), antioxidant peroxide (PsOXII), and chlorophyll a-b binding protein genes increased significantly in treated plants with MgO (3.1, 2.7, and 3.5-fold), fungicide (3.2, 2.8, and 2.8-fold), and Zn/MgO (3.5, 3, and 5-fold) compared to control, respectively. Pea plants treated with the tested nanoparticles generated more phenolic content than untreated controls. The application of fungicide and tested nanoparticles to peas greatly enhanced their growth properties. In light of our results, the application of these nanoparticles may represent a novel approach for controlling this pathogen. Full article

Yellow pitahaya (Selenicereus megalanthus Haw.) is increasing in popularity and is considered to be an exotic fruit with great potential for consumption due to its content of both nutritive and bioactive compounds with health-related properties. Pitahaya plants, grown in Ecuador, were treated with two elicitors: methyl jasmonate (MeJA) and methyl salicylate (MeSA), both at a 0.1 mM concentration. After harvesting, the fruits were transported to Spain and stored at two temperatures, 2 and 10 °C, for 55 days. The analytical determinations were physiological parameters (ethylene and respiration rates), organoleptic traits [firmness, color, total soluble solids (TSSs) and total acidity (TA)], and phytonutrients (total phenolics, carotenoids and total antioxidant activity). The results show that all the parameters evolved more rapidly at 10 °C than at 2 °C, which is due to storage temperature effects on fruit metabolism. For TSSs, reductions were observed at the two temperatures, while, for TA, a major reduction was obtained at 2 °C. Regarding storage, the respiration rates increased, especially at 2 °C. At the end of storage, total phenolics were higher in treated pitahayas. Moreover, fruits developed chilling injury (CI) at 2 °C based on the highest respiration rate and accelerated softening. Collectively, all the data suggest that both MeJA and MeSA could modulate yellow pitahaya ripening without detrimental effects on quality during postharvest storage. Full article

Methyl jasmonate (MeJA) is a defence-related phytohormone that triggers metabolic reprogramming in grapevines and modulates pathways associated with stress responses and secondary metabolism. However, the temporal organisation of leaf metabolic responses following MeJA elicitation remains insufficiently characterised. In this study, an untargeted metabolomic approach based on UPLC-QTOF-MS was applied to investigate the time-resolved metabolic response of Vitis vinifera L. cv. Tempranillo leaves following foliar application of 10 mM MeJA under controlled greenhouse conditions. Leaf samples were collected at 0, 3, 6, 18, 24, and 48 h post-treatment. After quality filtering, 2552 metabolite features were detected, of which 40 discriminant features met stringent statistical criteria (maximum fold change ≥ 2 and p ≤ 0.05). Putative annotation according to Metabolomics Standards Initiative guidelines (MSI levels 2–3) revealed modulation of several metabolite classes, including carbohydrate-derived conjugates, terpenoid-related metabolites, hydroxycinnamic acid derivatives, and flavonoid-associated compounds. Temporal profiling revealed structured and non-monotonic metabolic responses characterised by rapid early changes between 3 and 6 h, followed by delayed accumulation patterns peaking around 24 h. Early phases were mainly associated with carbohydrate-related metabolites, suggesting rapid redistribution of carbon resources after elicitor perception. These results indicate that MeJA-induced metabolic adjustment in Tempranillo leaves occurs through temporally differentiated response phases rather than a uniform metabolic shift, providing a time-resolved metabolomic framework for interpreting elicitor-driven defence responses in grapevine. Full article

Ceylon cinnamon (Cinnamomum verum J. Presl) bark essential oil (CBO) represents a promising source of natural bioactive compounds for biological plant protection. For the first time, the antibacterial and antifungal activity of CBO was systematically evaluated against a curated panel of phytopathogenic strains (IOR collection), revealing broad-spectrum efficacy across both bacteria and filamentous pathogens. This study evaluated its chemical composition, antimicrobial activity against phytopathogens, effects on bacterial metabolic activity, and its ability to induce plant defence responses. CBO was dominated by cinnamaldehyde, linalool, and eucalyptol. The oil exhibited strong antibacterial activity against Dickeya dadantii, Pectobacterium carotovorum, Pseudomonas syringae, and Xanthomonas hortorum as well as antifungal activity against Fusarium graminearum, F. culmorum, Rhizoctonia solani and Phytophthora cinnamomi. Metabolic assays revealed a marked reduction in bacterial metabolic activity, indicating that CBO disrupts physiological processes and inhibits growth. In planta experiments showed that foliar application of CBO stimulated PAL activity in wheat leaves without visible phytotoxic symptoms. These findings demonstrate a multifunctional mode of action of CBO, combining direct antimicrobial effects with the elicitation of plant defence responses, and support its potential application in sustainable crop protection. Full article

Loquat (Eriobotrya japonica Lindl.) is a subtropical evergreen fruit tree that accumulates abundant bioactive triterpene compounds with diverse pharmaceutical activities. Its leaves have been used in traditional Chinese medicine for over 1000 years. Methyl jasmonate (MeJA) is a conserved elicitor that stimulates plant secondary metabolism. However, the regulatory mechanisms of terpenoid biosynthesis after MeJA treatment in loquat callus remain largely unknown. In this study, we employed an integrated targeted metabolomic and transcriptomic approach to investigate the effect of exogenous MeJA on terpenoid biosynthesis in loquat callus. In total, 131 terpenoid compounds were detected, including 112 triterpenes, six triterpene saponins, seven diterpenoids, three sesquiterpenoids and three monoterpenoids. After MeJA treatment, a total of 55 and 33 differential metabolites (DEMs) were identified at 24 h and 48 h, respectively. Most DEMs were triterpene compounds, displaying increased accumulation. Among them, ursolic acid showed the highest accumulation at 24 h, and betulinic acid was most abundant at 48 h. Meanwhile, transcriptome analysis showed significant upregulation of terpenoid biosynthesis genes, including EjFPSs, EjSQEs, EjOSC2 and EjCYP716A2, as well as genes related to jasmonic acid (JA)-mediated signaling and JA-responsive genes in loquat callus treated with MeJA. Overall, these results provide a deeper understanding of the mechanism of terpenoid accumulation in loquat callus induced by MeJA and establish a theoretical basis for utilizing plant cell culture techniques to achieve production of the valuable terpenoid metabolites that are applied in the functional food and pharmacological industries. Full article

The objective of this study was to evaluate the preharvest application of γ-aminobutyric acid (GABA), melatonin (MT), and oxalic acid (OA), at different concentrations and application frequencies, on the physicochemical and microbiological quality of dried figs (cv. Calabacita) at commercial harvest and after 3 and 6 months of refrigerated storage. A further aim was to determine their impact on fungal populations and mycotoxin production. The results showed that untreated dried figs had a higher frequency of Aspergillus welwitschiae, A. tubingensis, and Aspergillus section Flavi, whereas elicitor-treated figs exhibited a lower incidence of toxigenic fungi. A. welwitschiae was the main ochratoxin A (OTA)-associated species detected, although the proportion of OTA-positive figs was lower in elicitor-treated samples than in the control. Aflatoxins (AFs) were detected only sporadically in 2 mM OA treatments, consistent with the limited activity of A. flavus at low storage temperatures. Conversely, Penicillium spp. were widespread but were associated with citrinin (CIT) production only under 2 mM OA treatments. Among the Alternaria toxins, alternariol (AOH) was detected solely in dried figs treated with 1 mM OA. Notably, all investigated mycotoxins were below the limit of detection (<LOD) in dried figs treated with 0.5 mM MT. Moderate elicitor concentrations (e.g., 0.5 mM MT and 50 mM GABA) and multiple preharvest applications generally provided the best balance between fungal suppression and fruit quality, significantly reducing Aspergillus spp. occurrence without promoting the growth of undesirable species. Overall, elicitor treatments decreased the incidence of toxigenic fungi, most likely through direct antifungal effects in senescent dried fruit rather than by inducing host defences. The combined use of preharvest elicitors with appropriate drying and storage conditions is a promising strategy to control fungal contamination and mycotoxin accumulation in dried figs while maintaining quality from preharvest storage. Further research is needed to optimise elicitor concentrations and application timing. Full article